1.6: Integumentary System
- Identify the anatomy of the integumentary system
- Describe the main functions of the integumentary system
- Spell the integumentary system medical terms and use correct abbreviations
- Identify the medical specialties associated with the integumentary system
- Explore common diseases, disorders, and procedures related to the integumentary system
Integumentary System Word Parts
Click on prefixes, combining forms, and suffixes to reveal a list of word parts to memorize for the Integumentary System.
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Introduction to the Integumentary System
The skin and accessory structures are the largest organ system in the human body.The integumentary system refers to the skin and its accessory structures. In the adult human body, the skin makes up about 16 percent of body weight and covers an area of 1.5 to 2 m 2 .
In fact, the skin and accessory structures are the largest organ system in the human body. The skin protects your inner organs and it is in need of daily care and protection to maintain its health.
Watch this video:
Media 6.1. The Integumentary System, Part 1 – Skin Deep: Crash Course A&P #6 [Video]. Copyright 2015 by CrashCourse .
Practice integumentary system medical terms.
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Anatomy (Structures) of the Integumentary System
The skin and its accessory structures make up the integumentary system, which provides the body with overall protection. The skin is made of multiple layers of cells and tissues, which are held to underlying structures by connective tissue. The deeper layer of skin is well vascularized . It also has numerous sensory, and autonomic and sympathetic nerve fibers ensuring communication to and from the brain.
The skin is composed of two main layers:
- The epidermis
-
The
dermis
- Beneath the dermis lies the hypodermis
- On the diagram above find the two layers of the skin; epidermis and dermis .
- The literal breakdown for hypodermis is below the dermis. On the diagram above where can you locate it?
- Can you find a hair follicle , hair root and hair shaft ?
- Keep reading to find out what the arrector pili muscle does when you are frightened.
Epidermis
The epidermis is composed of keratinized, stratified squamous epithelium. It is made of four or five layers of epithelial cells, depending on its location in the body. It is avascular .
- Thin skin has four layers of cells. From deep to superficial, these layers are the stratum basale , stratum spinosum, stratum granulosum, and stratum corneum. Most of the skin can be classified as thin skin.
- Thick skin is found only on the palms of the hands and the soles of the feet. It has a fifth layer, called the stratum lucidum, located between the stratum corneum and the stratum granulosum (see Figure 6.2 ).
The cells in all of the layers except the stratum basale are called keratinocytes . Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant properties. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from the deeper layers (see Figure 6.3 ).
Dermis
Papillary Layer
The papillary layer is made of loose, areolar connective tissue, which means the collagen and elastin fibers of this layer form a loose mesh. This superficial layer of the dermis projects into the stratum basale of the epidermis to form finger-like dermal papillae (see Figure 6.4 ).  In addition, the papillary layer contains phagocytes , that help fight bacteria or other infections that have breached the skin. This layer also contains lymphatic capillaries, nerve fibers, and Meissner corpuscles .
Reticular Layer
Underlying the papillary layer is the much thicker reticular layer, composed of dense, irregular connective tissue. This layer is well vascularized and has a rich sensory and sympathetic nerve supply. The reticular layer appears reticulated due to a tight meshwork of fibers. Elastin fibers provide some elasticity to the skin, enabling movement. Collagen fibers provide structure and tensile strength, with strands of collagen extending into both the papillary layer and the hypodermis. In addition, collagen binds water to keep the skin hydrated. Collagen injections and Retin-A creams help restore skin turgor by either introducing collagen externally or stimulating blood flow and repair of the dermis, respectively.
Hypodermis
The hypodermis serves to connect the skin to the underlying fascia of the bones and muscles. It is not strictly a part of the skin, although the border between the hypodermis and dermis can be difficult to distinguish. The hypodermis consists of well-vascularized, loose, areolar connective tissue and adipose tissue, which functions as a mode of fat storage and provides insulation and cushioning for the integument.
Practice labeling the layers of the skin.
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Physiology (Function) of the Integumentary System
The skin and accessory structures perform a variety of essential functions, such as protecting the body from invasion by microorganisms, chemicals, and other environmental factors; preventing dehydration; acting as a sensory organ; modulating body temperature and electrolyte balance; and synthesizing vitamin D. The underlying hypodermis has important roles in storing fats, forming a “cushion” over underlying structures, and providing insulation from cold temperatures.
Protection
The skin protects the body from wind, water, and UV sunlight. It acts as a protective barrier against water loss and it also is the first line of defense against abrasive activity such as grit, microbes, or harmful chemicals. Sweat excreted from sweat glands deters microbes from over-colonizing the skin surface by generating dermicidin, which has antibiotic properties.
Sensory Function
The skin acts as a sense organ because the epidermis, dermis, and the hypodermis contain specialized sensory nerve structures that detect touch, surface temperature, and pain. These receptors are more concentrated on the tips of the fingers, which are most sensitive to touch, especially the Meissner corpuscle , which responds to light touch, and the Pacinian corpuscle , which responds to vibration. Merkel cells, seen scattered in the stratum basale, are also touch receptors. In addition to these specialized receptors, there are sensory nerves connected to each hair follicle, pain and temperature receptors scattered throughout the skin, and motor nerves innervate the arrector pili muscles and glands. This rich innervation helps us sense our environment and react accordingly,
Thermoregulation
The integumentary system helps regulate body temperature through its tight association with the sympathetic nervous system . The sympathetic nervous system is continuously monitoring body temperature and initiating appropriate motor responses.
-
When the
body becomes warm
sweat glands, accessory structures to the skin, secrete water, salt, and other substances to cool the body.
- Even when the body does not appear to be noticeably sweating, approximately 500 mL of sweat are secreted a day.
-
If the
body becomes excessively warm
due to high temperatures, vigorous activity, or a combination of the two, sweat glands will be stimulated by the sympathetic nervous system to produce large amounts of sweat.
- When the sweat evaporates from the skin surface, the body is cooled as body heat is dissipated.
- In addition to sweating, arterioles in the dermis dilate so that excess heat carried by the blood can dissipate through the skin and into the surrounding environment (Figure 2b) .
- This accounts for the skin redness that many people experience when exercising.
-
When
body temperatures drop
, the arterioles constrict to minimize heat loss, particularly in the ends of the digits and tip of the nose.
- This reduced circulation can result in the skin taking on a whitish hue.
- Although the temperature of the skin drops as a result, passive heat loss is prevented, and internal organs and structures remain warm.
- If the temperature of the skin drops too much (such as environmental temperatures below freezing), the conservation of body core heat can result frostbite .
Can you describe the thermoregulation process between the integumentary system and the sympathetic system?
- When body temperature is too warm.
- When body temperature is too cold.
Vitamin D Synthesis
Vitamin D is essential for general immunity against bacterial, viral and fungal infections.
The epidermal layer of human skin synthesizes Vitamin D when exposed to UV radiation. In the presence of sunlight, a form of Vitamin D 3 called cholecalciferol is synthesized from a derivative of the steroid cholesterol in the skin. The liver converts cholecalciferol to calcidiol, which is then converted to calcitriol (the active chemical form of the vitamin) in the kidneys.
- Vitamin D is essential for normal absorption of calcium and phosphorous, which are required for healthy bones.
- The absence of sun exposure can lead to a lack of vitamin D in the body, in children this can cause rickets . Vitamin D deficiency in elderly individuals may lead to osteomalacia .
- In present day society, Vitamin D is added as a supplement to many foods, including milk and orange juice, compensating for the need for sun exposure. In addition to its essential role in bone health, Vitamin D is essential for general immunity against bacterial, viral, and fungal infections.
Watch this video:
Media 6.2. The Integumentary System, Part 2 – Skin Deeper: Crash Course A&P #7 [Online video]. Copyright 2015 by CrashCourse .
Accessory Structures
Accessory structures of the skin include hair, nails, sweat glands, and sebaceous glands. These structures embryologically originate from the epidermis and can extend down through the dermis into the hypodermis .
Hair
Hair is a keratinous filament growing out of the epidermis . It is primarily made of dead, keratinized cells. Strands of hair originate in an epidermal penetration of the dermis called the hair follicle. The hair shaft is the part of the hair not anchored to the follicle, and much of this is exposed at the skin’s surface. The rest of the hair, which is anchored in the follicle, lies below the surface of the skin and is referred to as the hair root. The hair root ends deep in the dermis at the hair bulb, and includes a layer of mitotically active basal cells called the hair matrix. The hair bulb surrounds the hair papilla, which is made of connective tissue and contains blood capillaries and nerve endings from the dermis (see Figure 6.6 ).
Hair Function
Hair serves a variety of functions, including protection, sensory input, thermoregulation, and communication. For example:
- Hair on the head protects the skull from the sun.
- Hair in the nose and ears, and around the eyes (eyelashes) defends the body by trapping and excluding dust particles that may contain allergens and microbes.
- Hair of the eyebrows prevents sweat and other particles from dripping into and bothering the eyes.
Hair also has a sensory function due to sensory innervation by a hair root plexus surrounding the base of each hair follicle. Hair is extremely sensitive to air movement or other disturbances in the environment, much more so than the skin surface. This feature is also useful for the detection of the presence of insects or other potentially damaging substances on the skin surface.
Each hair root is connected to a smooth muscle called the arrector pili that contracts in response to nerve signals from the sympathetic nervous system, making the external hair shaft “stand up.” The primary purpose for this is to trap a layer of air to add insulation. This is visible in humans as goose bumps and even more obvious in animals, such as when a frightened cat raises its fur. Of course, this is much more obvious in organisms with a heavier coat than most humans, such as dogs and cats.
Hair Growth, Loss and Colour
Hair grows and is eventually shed and replaced by new hair. Hair typically grows at the rate of 0.3 mm per day. On average, 50 hairs are lost and replaced per day. Hair loss occurs if there is more hair shed than what is replaced and can happen due to hormonal or dietary changes. Hair loss can also result from the aging process, or the influence of hormones. Similar to the skin, hair gets its colour from the pigment melanin, produced by melanocytes in the hair papilla. Different hair color results from differences in the type of melanin. As a person ages, the melanin production decreases, and hair tends to lose its color and becomes gray and/or white.
Nails
The nail bed is a specialized structure of the epidermis that is found at the tips of our fingers and toes. The nail body is formed on the nail bed, and protects the tips of our fingers and toes as they are the farthest extremities and the parts of the body that experience the maximum mechanical stress (see Figure 6.7 ). The nail body forms a back-support for picking up small objects with the fingers. The nail body is composed of densely packed dead keratinocytes .
The epidermis in this part of the body has evolved a specialized structure upon which nails can form. The nail body forms at the nail root, which has a matrix of proliferating cells from the stratum basale that enables the nail to grow continuously. The lateral nail fold overlaps the nail on the sides, helping to anchor the nail body. The nail fold that meets the proximal end of the nail body forms the nail cuticle, also called the eponychium.
The nail bed is rich in blood vessels, making it appear pink, except at the base, where a thick layer of epithelium over the nail matrix forms a crescent-shaped region called the lunula (the “little moon”). The area beneath the free edge of the nail, furthest from the cuticle, is called the hyponychium. It consists of a thickened layer of stratum corneum.
Sweat Glands
Sudoriferous Glands
When the body becomes warm, sudoriferous glands produce sweat to cool the body. Sweat glands develop from epidermal projections into the dermis and are classified as merocrine glands; that is, the secretions are excreted by exocytosis through a duct without affecting the cells of the gland. There are two types of sweat glands, each secreting slightly different products.
An eccrine sweat gland is type of gland that produces a hypotonic sweat for thermoregulation as described previously. These glands are found all over the skin’s surface, but are especially abundant on the palms of the hand, the soles of the feet, and the forehead ( Figure 6.8 ). They are coiled glands lying deep in the dermis, with the duct rising up to a pore on the skin surface, where the sweat is released. This type of sweat, released by exocytosis , is hypotonic and composed mostly of water, with some salt, antibodies, traces of metabolic waste, and dermicidin, an antimicrobial peptide. Eccrine glands are a primary component of thermoregulation in humans and thus help to maintain homeostasis .
An apocrine sweat gland is usually associated with hair follicles in densely hairy areas, such as armpits and genital regions. Apocrine sweat glands are larger than eccrine sweat glands and lie deeper in the dermis, sometimes even reaching the hypodermis, with the duct normally emptying into the hair follicle. In addition to water and salts, apocrine sweat includes organic compounds that make the sweat thicker and subject to bacterial decomposition and subsequent smell. The release of this sweat is under both nervous and hormonal control, and plays a role in the poorly understood human pheromone response. Most commercial antiperspirants use an aluminum-based compound as their primary active ingredient to stop sweat. When the antiperspirant enters the sweat gland duct, the aluminum-based compounds precipitate due to a change in pH and form a physical block in the duct, which prevents sweat from coming out of the pore.
Aluminum-based compounds due to a change in pH form a physical block in the sweat gland duct. This prevents sweating.
Sebaceous Glands
A sebaceous gland is a type of oil gland that is found all over the body and helps to lubricate and waterproof the skin and hair. Most sebaceous glands are associated with hair follicles. They generate and excrete sebum, a mixture of lipids, onto the skin surface, thereby naturally lubricating the dry and dead layer of keratinized cells of the stratum corneum, keeping it pliable. The fatty acids of sebum also have antibacterial properties, and prevent water loss from the skin in low-humidity environments. The secretion of sebum is stimulated by hormones, many of which do not become active until puberty. Thus, sebaceous glands are relatively inactive during childhood.
Words not Easily Broken into Word Parts
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Common Integumentary System Abbreviations
Many terms and phrases related to the integumentary system are abbreviated. Learn these common abbreviations by expanding the list below.
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Changes Due to Aging
All systems in the body accumulate subtle and some not-so-subtle changes as a person ages. Among these changes are reductions in cell division, metabolic activity, blood circulation, hormonal levels, and muscle strength (see Figure 6.9 ). In the skin, these changes are reflected in decreased mitosis in the stratum basale, leading to a thinner epidermis. The dermis, which is responsible for the elasticity and resilience of the skin, exhibits a reduced ability to regenerate, which leads to slower wound healing. The hypodermis, with its fat stores, loses structure due to the reduction and redistribution of fat, which in turn contributes to the thinning and sagging of skin.
A reduced sweating ability can cause some elderly to be intolerant to extreme heat.
The accessory structures also have lowered activity, generating thinner hair and nails, and reduced amounts of sebum and sweat. A reduced sweating ability can cause some elderly to be intolerant to extreme heat. Other cells in the skin, such as melanocytes and dendritic cells, also become less active, leading to a paler skin tone and lowered immunity. Wrinkling of the skin occurs due to breakdown of its structure, which results from decreased collagen and elastin production in the dermis, weakening of muscles lying under the skin, and the inability of the skin to retain adequate moisture.
Disease and Disorders
The integumentary system is susceptible to a variety of diseases, disorders, and injuries. These range from annoying but relatively benign bacterial or fungal infections that are categorized as disorders, to skin cancer and severe burns, which can be fatal. In this section, you will learn several of the most common skin conditions.
One of the most talked about diseases is skin cancer . Most cancers are identified by the organ or tissue in which the cancer originates. One common form of cancer is skin cancer.
In general, cancers result from an accumulation of DNA mutations. These mutations can result in cell populations that do not die when they should and uncontrolled cell proliferation that leads to tumors. Although many tumors are benign , some metastasize . Cancers are characterized by their ability to metastasize.
Sun Damage
It requires about 10 days after initial sun exposure for melanin synthesis to peak, which is why pale-skinned individuals tend to suffer sunburns of the epidermis initially. Dark-skinned individuals can also get sunburns, but are more protected than are pale-skinned individuals. Too much sun exposure can eventually lead to wrinkling due to the destruction of the cellular structure of the skin, and in severe cases, can cause sufficient DNA damage to result in skin cancer. When there is an irregular accumulation of melanocytes in the skin, freckles appear. Moles are larger masses of melanocytes, and although most are benign, they should be monitored for changes that might indicate the presence of cancer (see Figure 6.10 ).
Basal Cell Carcinoma (BCC)
Basal cell carcinoma is a form of cancer that affects the mitotically active stem cells in the stratum basale of the epidermis. It is the most common of all cancers that occur in the United States and is frequently found on the head, neck, arms, and back, which are are as that are most susceptible to long-term sun exposure. Although UV rays are the main culprit, exposure to other agents, such as radiation and arsenic, can also lead to this type of cancer. Wounds on the skin due to open sores, tattoos, burns, etc. may be predisposing factors. Basal cell carcinomas start in the stratum basale and usually spread along this boundary. At some point, they begin to grow toward the surface and become an uneven patch, bump, growth, or scar on the skin surface (see Figure 6.11 ). Like most cancers, basal cell carcinomas respond best to treatment when caught early. Treatment options include surgery, freezing (cryosurgery), and topical ointments.
Squamous Cell Carcinoma (SCC)
Squamous cell carcinoma is a cancer that affects the keratinocytes of the stratum spinosum and presents as lesions commonly found on the scalp, ears, and hands (see Figure 6.12 ). It is the second most common skin cancer. The American Cancer Society reports that two of 10 skin cancers are squamous cell carcinomas, and it is more aggressive than basal cell carcinoma. If not removed, these carcinomas can metastasize . Surgery and radiation are used to cure squamous cell carcinoma .
Melanoma
A melanoma is a cancer characterized by the uncontrolled growth of melanocytes, the pigment-producing cells in the epidermis. Typically, a melanoma develops from a mole. It is the most fatal of all skin cancers, as it is highly metastatic and can be difficult to detect before it has spread to other organs. Melanomas usually appear as asymmetrical brown and black patches with uneven borders and a raised surface (see Figure 6.13 ). Treatment typically involves surgical excision and immunotherapy.
ABCDE for Early Diagnosis
Doctors often give their patients the following ABCDE mnemonic to help with the diagnosis of early-stage melanoma. If you observe a mole on your body displaying these signs, consult a doctor.
A
symmetry – the two sides are not symmetrical
B
orders – the edges are irregular in shape
C
olor – the color is varied shades of brown or black
D
iameter – it is larger than 6 mm (0.24 in)
E
volving – its shape has changed
Some specialists cite the following additional signs for the most serious form, nodular melanoma:
Elevated – it is raised on the skin surface
Firm – it feels hard to the touch
Growing – it is getting larger
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. This is primarily due to the inability of melanocytes to produce melanin. Individuals with albinism tend to appear white or very pale due to the lack of melanin in their skin and hair. Recall that melanin helps protect the skin from the harmful effects of UV radiation. Individuals with albinism tend to need more protection from UV radiation, as they are more prone to sunburns and skin cancer. They also tend to be more sensitive to light and have vision problems due to the lack of pigmentation on the retinal wall (Betts, et al., 2013)
Treatment of this disorder usually involves addressing the symptoms, such as limiting UV light exposure to the skin and eyes. In vitiligo , the melanocytes in certain areas lose their ability to produce melanin, possibly due to an autoimmune reaction. This leads to a loss of color in patches (see Figure 6.14 ). Neither albinism nor vitiligo directly affects the lifespan of an individual (Betts, et al., 2013)
Changes in Skin Colouration
Other changes in the appearance of skin colouration can be indicative of diseases associated with other body systems.
- Liver disease or liver cancer can cause the accumulation of bile and the yellow pigment bilirubin, leading to the skin appearing yellow or jaundiced .
- Tumors of the pituitary gland can result in the secretion of large amounts of melanocyte-stimulating hormone (MSH), which results in a darkening of the skin.
- Addison’s disease can stimulate the release of excess amounts of adrenocorticotropic hormone (ACTH), which can give the skin a deep bronze color
- A sudden drop in oxygenation can affect skin color, causing the skin to initially turn ashen (white).
- A prolonged reduction in oxygen levels, dark red deoxyhemoglobin becomes dominant in the blood, making the skin appear blue , a condition referred to as cyanosis . This happens when the oxygen supply is restricted, as when someone is experiencing difficulty in breathing because of asthma or a heart attack. However, in these cases the effect on skin color has nothing do with the skin’s pigmentation (Betts, et al., 2013)
Skin Disorders
Two common skin disorders are eczema and acne . Eczema is an inflammatory condition and occurs in individuals of all ages. Acne involves the clogging of pores, which can lead to infection and inflammation, and is often seen in adolescents. Other disorders, include seborrheic dermatitis (on the scalp), psoriasis, fungal infections, cold sores, impetigo, scabies, hives, and warts (Betts, et al., 2013).
Eczema
Eczema is an allergic reaction that manifests as dry, itchy patches of skin that resemble rashes (see Figure 6.15 ). It may be accompanied by swelling of the skin, flaking, and in severe cases, bleeding. Symptoms are usually managed with moisturizers, corticosteroid creams, and immunosuppressants (Betts, et al., 2013).
Acne
Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). It is most common along with the onset of puberty due to associated hormonal changes, but can also occur in infants and continue into adulthood. Hormones, such as androgens, stimulate the release of sebum. An overproduction and accumulation of sebum along with keratin can block hair follicles. This plug is initially white. The sebum, when oxidized by exposure to air, turns black. Acne results from infection by acne-causing bacteria ( Propionibacterium and Staphylococcus ), which can lead to redness and potential scarring due to the natural wound healing process (see Figure 6.16 ) (Betts, et al., 2013).
Ringworm
Tinea or dermatophytosis is often referred to as ringworm. Ringworm presents as a circular rash that is itchy and red and can be found on various parts of the body. It is referred to by the location that it is found:
-
- Tinea Pedis – feet or commonly referred to as athlete’s feet
- Tinea Capitis – scalp
- Tinea barbae – beard
- Tinea manuum – hands
- Tinea unguium – Toenails and fingernails also called onychomycosis
- Tinea corporis – Body parts such as arms and legs (Center for Disease Control and Prevention, 2018a)
To learn more about ringworm, visit the Center for Disease Control and Prevention’s web page on fungal infections.
Psoriasis
Psoriasis is a chronic autoimmune disorder that results in patches of thick red skin with the appearance of silvery scales.  Psoriasis can be confused with other skin disease so a dermatologist is the best physician to diagnosis psoriasis. Treatments may include creams, ointments, ultraviolet light therapy and medication (Center for Disease Control and Prevention, 2018). To learn more, visit the Center for Disease Control and Prevention’s web page on psoriasis .
Injuries
Skin injuries set off a healing process that occurs in several overlapping stages.
- The first step to repairing damaged skin is the formation of a blood clot that helps stop the flow of blood and scabs over with time. Many different types of cells are involved in wound repair, especially if the surface area that needs repair is extensive.
- Before the basal stem cells of the stratum basale can recreate the epidermis, fibroblasts mobilize and divide rapidly to repair the damaged tissue by collagen deposition, forming granulation tissue.
- Blood capillaries follow the fibroblasts and help increase blood circulation and oxygen supply to the area.
- Immune cells, such as macrophages, roam the area and engulf any foreign matter to reduce the chance of infection (Betts, et al., 2013).
Burns
A burn results when the skin is damaged by intense heat, radiation, electricity, or chemicals. The damage results in the death of skin cells, which can lead to a massive loss of fluid. Dehydration, electrolyte imbalance, and renal and circulatory failure follow, which can be fatal. Burn patients are treated with intravenous fluids to offset dehydration , as well as intravenous nutrients that enable the body to repair tissues and replace lost proteins. Another serious threat to the lives of burn patients is infection . Burned skin is extremely susceptible to bacteria and other pathogens , due to the loss of protection by intact layers of skin (Betts, et al., 2013).
Burn Classification
Burns are sometimes measured in terms of the size of the total surface area affected. This is referred to as the rule of nines , which associates specific anatomical areas with a percentage that is a factor of nine (see Figure 6.17 ) (Betts, et al., 2013).
Burns are also classified by the degree of their severity .
- A first-degree burn is a superficial burn that affects only the epidermis. Although the skin may be painful and swollen, these burns typically heal on their own within a few days. Mild sunburn fits into the category of a first-degree burn.
- A second-degree burn goes deeper and affects both the epidermis and a portion of the dermis. These burns result in swelling and a painful blistering of the skin. It is important to keep the burn site clean and sterile to prevent infection. If this is done, the burn will heal within several weeks.
- A third-degree burn fully extends into the epidermis and dermis, destroying the tissue and affecting the nerve endings and sensory function. These are serious burns that may appear white, red, or black; they require medical attention and will heal slowly without it.
- A fourth-degree burn is even more severe, affecting the underlying muscle and bone.
Oddly, third and fourth-degree burns are usually not as painful because the nerve endings themselves are damaged. Full-thickness burns cannot be repaired by the body, because the local tissues used for repair are damaged and require debridement , or amputation in severe cases, followed by grafting of the skin from an unaffected part of the body, or from skin grown in tissue culture for grafting purposes. Skin grafts are required when the damage from trauma or infection cannot be closed with sutures or staples (Betts et al., 2013).
Scars and Keloids
Most cuts or wounds, with the exception of ones that only scratch the epidermis, lead to scar formation. Scarring occurs in cases in which there is repair of skin damage, but the skin fails to regenerate the original skin structure. Fibroblasts generate scar tissue in the form of collagen, and the bulk of repair is due to the basket-weave pattern generated by collagen fibers and does not result in regeneration of the typical cellular structure of skin. Instead, the tissue is fibrous in nature and does not allow for the regeneration of accessory structures, such as hair follicles, sweat glands, or sebaceous glands (Betts, et al., 2013).
Sometimes, there is an overproduction of scar tissue, because the process of collagen formation does not stop when the wound is healed; this results in a keloid . In contrast, scars that result from acne and chickenpox have a sunken appearance and are called atrophic scars (Betts, et al., 2013)
Scarring of skin after wound healing is a natural process and does not need to be treated further. Application of mineral oil and lotions may reduce the formation of scar tissue. However, modern cosmetic procedures, such as dermabrasion, laser treatments, and filler injections have been invented as remedies for severe scarring. All of these procedures try to reorganize the structure of the epidermis and underlying collagen tissue to make it look more natural (Betts, et al., 2013).
Bedsores and Stretch Marks
Skin and its underlying tissue can be affected by excessive pressure. One example of this is called a bedsore. Bedsores, also called decubitus ulcers, are caused by constant, long-term, unrelieved pressure on certain body parts that are bony, reducing blood flow to the area and leading to necrosis . Bedsores are most common in elderly patients who have debilitating conditions that cause them to be immobile. Most hospitals and long-term care facilities have the practice of turning the patients every few hours to prevent the incidence of bedsores. If left untreated bedsores can be fatal if they become infected (Betts, et al., 2013)
The skin can also be affected by pressure associated with rapid growth. A stretch mark results when the dermis is stretched beyond its limits of elasticity, as the skin stretches to accommodate the excess pressure. Stretch marks usually accompany rapid weight gain during puberty and pregnancy. They initially have a reddish hue, but lighten over time. Other than for cosmetic reasons, treatment of stretch marks is not required. They occur most commonly over the hips and abdomen (Betts, et al., 2013).
Calluses
When you wear shoes that do not fit well and are a constant source of abrasion on your toes, you tend to form a callus at the point of contact. This occurs because the basal stem cells in the stratum basale are triggered to divide more often to increase the thickness of the skin at the point of abrasion to protect the rest of the body from further damage. This is an example of a minor or local injury, and the skin manages to react and treat the problem independent of the rest of the body. Calluses can also form on your fingers if they are subject to constant mechanical stress, such as long periods of writing, playing string instruments, or video games. A corn is a specialized form of callus. Corns form from abrasions on the skin that result from an elliptical-type motion (Betts, et al., 2013).
Medical Terms in Context
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Medical Specialties and Procedures Related to the Integumentary System
A dermatologist is a medical doctor with specialized training in treating diseases, disorders and injuries related to the integumentary system and its accessory structures. There are many dermatologic subspecialties such as cosmetic dermatology, dermatopathology and pediatric dermatology. To learn more visit the Dermatology and Subspecialties section of the Canadian Dermatology Association website.
Dermatologists can be specially trained to perform a procedure called Mohs surgery. Mohs surgery excises skin cancers in thin layers until all cancer is removed from the tissue (Mayo Clinic Staff, 2017).
Integumentary System Vocabulary
Adipocytes
Fat cells.
Adipose tissue
Fat tissue.
Autonomic nerve fibers
Unconsciously regulates communication to and from the brain.
Avascular
Without blood vessels.
Benign
Noncancerous, harmless.
Cancer
A process where abnormal cells in the body divide uncontrollably.
Cyanosis
Abnormal condition of blue (bluish colour, lips and nail beds). Typically caused by low oxygenation.
Debridement
Excision of damaged tissue or foreign object.
Dehydration
Loss of fluids/water is greater than what is taken in.
Dermatologic
Pertaining to dermatology.
Dermatopathology
Study of diseases of the skin.
Dermis
The layer of skin that is made of dense, irregular connective tissue that houses blood vessels, hair follicles, sweat glands, and other structures.
Epidermis
Outer layer of skin, made of closely packed epithelial cells.
Excises
Remove by cutting out.
Exocytosis
Active transport of molecules out of the cell.
Fascia
Fibrous tissue.
Frostbite
Conservation of core body heat results in the skin actually freezing.
Hypodermis
Literally means below the dermis. The layer of skin below the dermis that is composed mainly of loose connective and fatty tissues.
Infection
Invasion by disease-causing organisms.
Intravenous
Pertaining to within the vein.
Jaundiced
Yellow-coloured.
Keloid
Formation of a raised or hypertrophic scar.
Keratinocytes
Cells that manufacture and store the protein keratin.
Meissner corpuscle
Tactile corpuscle that responds to light and touch, touch receptor.
Meissner corpuscles
Tactile corpuscle that responds to light and touch, touch receptors.
Melanocytes
Specialized cells that produce melanin which is a dark pigment responsible for colouration of skin and hair.
Metastasize
Production of cells that can mobilize and establish tumors in other organs of the body.
Necrosis
Tissue death.
Osteomalacia
Softening of the bones.
Pacinian corpuscle
Lamellated corpuscle that responds to vibration.
Pathogens
Disease-causing agents.
Phagocytes
Cells that engulf and absorb bacteria and cell particles.
Reticulated
Net like.
Rickets
A painful condition in children where bones are misshapen due to a lack of calcium, causing bow leggedness.
Scar
Collagen-rich skin formed after the process of wound healing that differs from normal skin.
Stratum Basale
Deepest layer of the epidermal.
Sympathetic nerve fibers
Flight or fight response determines communication to and from the brain.
Sympathetic Nervous System
Responsible for fight or flight responses.
Vascularized
Has numerous blood vessels.
Test Yourself
An interactive or media element has been excluded from this version of the text. You can view it online here:
https://ecampusontario.pressbooks.pub/medicalterminology/?p=245
References
Centers for Disease Control and Prevention. (2018, October 25). Psoriasis . Centers for Disease Control and Prevention: Fungal Diseases. https://www.cdc.gov/psoriasis/
Centers for Disease Control and Prevention. (2018a, August 6). Ringworm . Centers for Disease Control and Prevention: Fungal Diseases. https://www.cdc.gov/fungal/diseases/ringworm/definition.html
CrashCourse. (2015, January 6). The Integumentary system, part 1 – skin deep: Crash Course A&P #6 [Video]. YouTube. https://youtu.be/Orumw-PyNjw
CrashCourse. (2015, February 16). The Integumentary system, part 2 – skin deeper: Crash Course A&P #7 [Video]. YouTube. https://youtu.be/EN-x-zXXVwQ
Mayo Clinic Staff. (2017, September 6). Mohs surgery . Mayo Clinic. https://www.mayoclinic.org/tests-procedures/mohs-surgery/about/pac-20385222#:~:text=Mohs%20surgery%20is%20a%20precise,known%20as%20Mohs%20micrographic%20surgery .
Image Descriptions
Figure 6.1 image description: This illustration shows a cross section of skin tissue. The outermost layer is called the epidermis, and occupies one fifth of the cross section. Several hairs are emerging from the surface. The epidermis dives around one of the hairs, forming a follicle. The middle layer is called the dermis, which occupies four fifths of the cross section. The dermis contains an erector pilli muscle connected to one of the follicles. The dermis also contains an eccrine sweat gland, composed of a bunch of tubules. One tubule travels up from the bunch, through the epidermis, opening onto the surface a pore. There are two string-like nerves travelling vertically through the dermis. The right nerve is attached to a Pacinian corpuscle, which is a yellow structure consisting of concentric ovals similar to an onion. The lowest level of the skin, the hypodermis, contains fatty tissue, arteries, and veins. Blood vessels travel from the hypodermis and connect to hair follicles and erector pilli muscle in the dermis. [Return to Figure 6.1].
Figure 6.2 image description: Part A is a micrograph showing a cross section of thin skin. The topmost layer is a thin, translucent layer with irregular texture and areas where cells are sloughing off. The deepest layer is dark purple and extends into the third layer with finger like projections. The third light purple layer contains thin bands of fibers and small, dark cells. The fourth, and deepest layer, is darker than the third layer, but is still light purple. It contains thick fiber bands that are loosely packed. Part B is a magnified view of the epidermis of thick skin. It shows the topmost layer is five times thicker than the topmost layer of thin skin. The topmost layer of thick skin is also denser and less translucent than the topmost layer of thin skin. [Return to Figure 6.2].
Figure 6.3 image description: The outer layer of cells in this micrograph is the thinnest layer and stained deep purple due to full keratinization of dead cells. The next layer occupies one quarter of the micrograph, is lightly stained, and is a dense collection of cells. The third layer from the top is mostly white, with lightly stained, loosely-packed strands radiating in random directions. The bottom-most layer is densely-packed, with thick bands of highly organized muscle tissue that are darkly stained. [Return to Figure 6.3].
Figure 6.4 image description: This micrograph shows layers of skin in a cross section. The papillary layer of the dermis extends between the downward fingers of the darkly stained epidermis. The papillary layer appears finer than the reticular layer, consisting of smaller, densely-packed fibers. The reticular layer is three times thicker than the papillary layer and contains larger, thicker fibers. The fibers seem more loosely packed than those of the papillary layer, with some separated by empty spaces. Both layers of the dermis contain cells with darkly stained nuclei. [Return to Figure 6.4].
Figure 6.5 image description: Part A is a photo of a man skiing with several snow-covered trees in the background. Part B is a diagram with a right and left half. The left half is titled “ Heat is retained by the body,” while the right half is titled “Heat loss through radiation and convection.” Both show blood flowing from an artery through three capillary beds within the skin. The beds are arranged vertically, with the topmost bed located along the boundary of the dermis and epidermis. The bottommost bed is located deep in the hypodermis. The middle bed is evenly spaced between the topmost and bottommost beds. In each bed, oxygenated blood (red) enters the bed on the left and deoxygenated blood (blue) leaves the bed on the right. The left diagram shows a picture of snowflakes above the capillary beds, indicating that the weather is cold. Blood is only flowing through the deepest of the three capillary beds, as the upper beds are closed off to reduce heat loss from the outer layers of the skin. The right diagram shows a picture of the sun above the capillary beds, indicating that the weather is hot. Blood is flowing through all three capillary beds, allowing heat to radiate out of the blood, increasing heat loss. Part C is a photo of a man running through a forested trail on a summer day. [Return to Figure 6.5].
Figure 6.6 image description: A cross section of the skin containing a hair follicle. The follicle is teardrop shaped. Its enlarged base, labeled the hair bulb, is embedded in the hypodermis. The outermost layer of the follicle is the epidermis, which invaginates from the skin surface to envelope the follicle. Within the epidermis is the outer root sheath, which is only present on the hair bulb. It does not extend up the shaft of the hair. Within the outer root sheath is the inner root sheath. The inner root sheath extends about half of the way up the hair shaft, ending midway through the dermis. The hair matrix is the innermost layer. The hair matrix surrounds the bottom of the hair shaft where it is embedded within the hair bulb. The hair shaft, in itself, contains three layers: the outermost cuticle, a middle layer called the cortex, and an innermost layer called the medulla. [Return to Figure 6.6].
Figure 6.7 image description: The anatomy of the fingernail region. The top image shows a dorsal view of a finger. The proximal nail fold is the part underneath where the skin of the finger connects with the edge of the nail. The eponychium is a thin, pink layer between the white proximal edge of the nail (the lunula), and the edge of the finger skin. The lunula appears as a crescent-shaped white area at the proximal edge of the pink-shaded nail. The lateral nail folds are where the sides of the nail contact the finger skin. The distal edge of the nail is white and is called the free edge. An arrow indicates that the nail grows distally out from the proximal nail fold. The lower image shows a lateral view of the nail bed anatomy. In this view, one can see how the edge of the nail is located just proximal to the nail fold. This end of the nail, from which the nail grows, is called the nail root. [Return to Figure 6.7].
Figure 6.8 image description: An illustration of an eccrine sweat gland embedded in a cross section of skin tissue. The eccrine sweat gland is a bundle of white tubes embedded in the dermis. A single white tube travels up from the bundle and opens on to the surface of the epidermis. The opening is called a pore. There are several pores on the small block of skin portrayed in this diagram. [Return to Figure 6.8].
Figure 6.9 image description: This figure consists of two photos. One photo shows a young woman on the phone. Her skin is smooth and unwrinkled. The other photo shows an elderly women in the same posture while on the phone. The skin of her hands and forearms is wrinkled. [Return to Figure 6.9].
Figure 16.10 image description: Five photos of moles. The three upper photos show moles that are small, flat, and dark brown. The bottom left photo shows a dark black mole that is raised above the skin. The bottom right photo shows a large, raised, reddish mole with protruding hairs. [Return to Figure 6.10].
Figure 16.17 image description: This diagram depicts the percentage of the total body area burned when a victim suffers complete burns to regions of the body. Complete burning of the face, head and neck account for 19% of the total body area. Burning of the chest, abdomen and entire back above the waist accounts for 36% of the total body area. Anterior and posterior surfaces of the arms and hands account for 18% of the total body area (9% for each arm). The anterior and posterior surface of both legs, along with the buttocks, accounts for 36% of the total body area (18% for each leg). Finally, the anterior and posterior surfaces of the genitalia account for 1% of the total body area. [Return to Figure 6.17].
Unless otherwise indicated, this chapter contains material adapted from Anatomy and Physiology (on OpenStax ), by Betts, et al. and is used under a a CC BY 4.0 international license . Download and access this book for free at https://openstax.org/books/anatomy-and-physiology/pages/1-introduction .


2.8: Test Yourself- Answers
1. What is the most accurate way to take the temperature of a one-year-old client?
a. Oral temperature
b. Rectal temperature **
c. Axillae temperature
d. Tympanic temperature
Rationale: The correct answer is b (rectal temperature). Rectal temperature is the most accurate measurement method for children under two years of age, who are not able to readily follow directions.
2. An adult client is drinking coffee. How should the healthcare provider measure the client’s temperature? Select all that apply .
a. Take the client’s oral temperature right away
b. Take the client’s axillary temperature right away **
c. Take the client’s tympanic temperature right away **
d. Take the client’s rectal temperature in five minutes
e. Wait two minutes and take the client’s oral temperature
Rationale: The correct answers are b and c (take the client’s axillary or tympanic temperature right away). Recent consumption of a hot drink or cold drink alters a client’s oral temperature. Thus, temperature is taken via the axillary or tympanic route if a client has recently had a hot or cold drink. You can take an oral temperature if you wait 15 minutes after hot drink consumption.
3. What is the best way to measure temperature in a client who is confused? Select all that apply.
a. Oral temperature
b. Rectal temperature
c. Axillary temperature **
d. Tympanic temperature **
e. Temporal artery temperature **
Rationale: The correct answers are c, d, and e (axillary, tympanic and temporal artery temperature). A client who is confused often cannot follow directions, so they may not follow directions to close their mouth as required when taking an oral temperature. Additionally, it is not safe to measure rectal temperature when a client is confused. Thus, it is best to measure axillary, tympanic, or temporal artery temperature.
4. An infant’s tympanic temperature is 37.7°C. How should the healthcare provider respond?
a. Apply a cold compress
b. Re-take in the other ear
c. Recognize this as normal **
d. Take a rectal temperature
Rationale: The correct answer is c (recognize this as normal). A temperature of 37.7°C is normal for an infant, so no further action is required.
5. How should the healthcare provider take the temperature of an adult client who is post-operation day two following oral surgery?
a. Avoid measuring temperature
b. Take rectal temperature once a shift
c. Take tympanic temperature as needed **
d.T ake oral temperature every four hours
Rationale: The correct answer is c (tympanic temperature). Taking oral temperature is avoided after oral surgery, and taking rectal temperature is avoided in the adult population. Thus, the best method is to measure tympanic temperature.


12.1: The Exploitation of Symmetry Can Help Simplify Numerical Calculations
To a fully understand the math behind group theory one needs to take a look at the theory portion of the Group Theory topic or refer to one of the reference text listed at the bottom of the page. Never the less as Chemist the object in question we are examining is usually a molecule. Though we live in the 21 st century and much is known about the physical aspects that give rise to molecular and atomic properties. The number of high level calculations that need to be performed can be both time consuming and tedious. To most experimentalist this task is takes away time and is usually not the integral part of their work. When one thinks of group theory applications one doesn't necessarily associated it with everyday life or a simple toy like a Rubik's cube. A Rubik's cube is an a cube that has a \(3 \times 3\) array of different colored tiles on each of its six surfaces, for a total of 54 tiles. Since the cube exist in 3D space, the three axis are \(x\), \(y\), \(z\). Since the rubik's cube only allows rotation which are called operations, there are three such operations around each of the \(x\), \(y\), \(z\) axis.
Of course the ultimate challenge of a Rubik's cube is to place all six colors on each of the six faces. By performing a series of such operations on the Rubik's cube one can arrive at a solution (A link of a person solving a Rubik's cube 1 in 10.4s with operations performed noted, the operations performed will not translate to chemistry applications but it is a good example of how symmetry operations arrive at a solution). The operations shown in the Rubik's cube case are inherent to the make up of the cube, i.e., the only operations allowed are the rotations along the x, y, z axis. Therefore the Rubik's cube only has x,y,z rotation operations. Similarly the operations that are specific to a molecule are dependent on its symmetry.
Using group theory, we can exploit the symmetry of molecules to give us a rich amount of information on the molecular orbitals, rotations, and vibrations of bonds, to name a few. Making symmetry arguments, we can skip complicated quantum calculations to gain qualitatively accurate information.
In section 10.7 , we used Hückel theory to explore the \(\pi\) bonding network of benzene by constructing linear combinations of \(2p_x\) atomic orbitals on the carbon atoms. In doing so, the roots of the secular equations were found via solving the \(6 \times 6\) secular determinant.
\[\left|\begin{array}{cccccc}x&1&0&0&0&1\\1&x&1&0&0&0\\0&1&x&1&0&0\\0&0&1&x&1&0\\0&0&0&1&x&1\\1&0&0&0&1&x\end{array}\right|=0\label{31} \]
Since the secular determinant is a \(6 \times 6\) matrix, there are six solutions or values of \(x\) that can be determined after expanding the determinant into the resulting (6th-order) polynomial.
\[ x^6-6x^4 + 9x^2 -4 =0 \label{poly1} \]
Secular determinants are formulated in terms of a specific basis set; i.e., a set of functions that describe the wavefunctions. For the determinnat in Equation \(\ref{31}\), that basis set is the the \(\{|2p_z \rangle \}\) orbitals on the carbons. However, any basis set can be used to represent the determinant (long as it span the same space). For example, the following linear combination of \(\{|2p_z \rangle \}\) orbitals could also be used:
\[\begin{align} & | \phi_1 \rangle = \dfrac{1}{\sqrt{6}} \left[ | 2p_{z1} \rangle+ | 2p_{z2} \rangle + | 2p_{z3} \rangle + | 2p_{z4} \rangle + | 2p_{z5} \rangle + | 2p_{z6} \rangle \right] \nonumber \\ & | \phi_2 \rangle = \dfrac{1}{\sqrt{4}} \left[ | 2p_{z2} \rangle + | 2p_{z3} \rangle - | 2p_{z4} \rangle - | 2p_{z5} \rangle \right] \nonumber \\ & | \phi_3 \rangle = \dfrac{1}{\sqrt{3}} \left[ | 2p_{z1} \rangle + \dfrac{1}{2}| 2p_{z2} \rangle - \dfrac{1}{2} | 2p_{z3} \rangle - | 2p_{z4} \rangle - \dfrac{1}{2} | 2p_{z5} \rangle + \dfrac{1}{2} | 2p_{z6} \rangle \right] \nonumber \\ & | \phi_4 \rangle = \dfrac{1}{\sqrt{4}} \left[ | 2p_{z2} \rangle - | 2p_{z3} \rangle + | 2p_{z4} \rangle - | 2p_{z5} \rangle \right] \nonumber \\ & | \phi_5 \rangle = \dfrac{1}{\sqrt{3}} \left[ | 2p_{z1} \rangle - \dfrac{1}{2}| 2p_{z2} \rangle - \dfrac{1}{2} | 2p_{z3} \rangle + | 2p_{z4} \rangle - \dfrac{1}{2} | 2p_{z5} \rangle - \dfrac{1}{2} | 2p_{z6} \rangle \right] \nonumber \\ & | \phi_6 \rangle = \dfrac{1}{\sqrt{6}} \left[ | 2p_{z1} \rangle- | 2p_{z2} \rangle + | 2p_{z3} \rangle - | 2p_{z4} \rangle + | 2p_{z5} \rangle - | 2p_{z6} \rangle \right] \nonumber \end{align} \nonumber \]
In this new basis set \(\{\phi \rangle \}\), the secular determinant Equation \(\ref{31}\) is represented as
\[\left|\begin{array}{cccccc} x+2&0&0&0&0&0 \\0&x-2&0&0&0&0 \\0&0&x+1& \dfrac{x+1}{2}&0&0 \\0&0& \dfrac{x+1}{2} &x+1&0&0 \\0&0&0&0&x-1& \dfrac{x-1}{2} \\0&0&0&0& \dfrac{x-1}{2} &x-1\end{array}\right|=0\label{32} \]
This is the determinant into a bock diagonal form; which can be expanded into a product of smaller determinants to give the polynomial
\[ \dfrac{9}{16} ( x +2)(x-2)(x+1)^2(x-1)^2=0 \nonumber \]
The roots to this equation are \(\pm2\), \(\pm1\) and \(\pm 1\). This is not surprising since these are the same roots obtained from expanding the determinant in the original basis set (Equation \(\ref{poly1}\)). You may remember that the selection of a specific basis set to represent a function does not change the fundamental nature of the function (e.g., a parabola in 2D space is the same curve if represented in terms of Cartesian coordinates (\(x\) and \(y\)) or polar coordinates (\(\theta\) and \(r\)), which both span 2-D space).
As you recall, Hückel theory (irrespective of the basis set ) was used to simplify the general secular determinant (e.g., for benzene)
\[\left|\begin{array}{cccccc} H_{11} - ES_{11} & H_{12} - ES_{12} & H_{13} - ES_{13} & H_{14} - ES_{14} & H_{15} - ES_{15} & H_{16} - ES_{16} \\ H_{21} - ES_{21} & H_{22} - ES_{22} & H_{23} - ES_{23} & H_{24} - ES_{24} & H_{25} - ES_{25} & H_{26} - ES_{26} \\ H_{31} - ES_{31} & H_{32} - ES_{32} & H_{33} - ES_{33} & H_{34} - ES_{34} & H_{35} - ES_{35} & H_{36} - ES_{36} \\ H_{41} - ES_{41} & H_{42} - ES_{42} & H_{43} - ES_{43} & H_{44} - ES_{44} & H_{45} - ES_{45} & H_{46} - ES_{46} \\ H_{51} - ES_{51} & H_{52} - ES_{52} & H_{53} - ES_{53} & H_{54} - ES_{54} & H_{55} - ES_{55} & H_{56} - ES_{56} \\ H_{61} - ES_{61} & H_{62} - ES_{62} & H_{63} - ES_{63} & H_{64} - ES_{64} & H_{65} - ES_{65} & H_{66} - ES_{6} \end{array}\right|=0\label{33} \]
where \( H_{ij}\) are the Hamiltonian matrix elements
\[ H_{ij} = \langle \phi_i | \hat{H} | \phi_j \rangle = \int \phi _{i}H\phi _{j}\mathrm {d} v \nonumber \]
and \( S_{ij} \) are the overlap integrals.
\[ S_{ij}= \langle \phi_i | \phi_j \rangle = \int \phi _{i}\phi _{j}\mathrm {d} v \nonumber \]
In general, this involves solving 36 Hamiltonian matrix elements (\(H_{ij}\)) and 36 overlap integrals (\(S_{ij}\)), which can be a daunting task to do by hand without the assumptions of Hückel theory to help out. As with the application of Hückel theory, which was used to set most of these integrals to zero, solving for the energies from Equation \(\ref{33}\) can be simplified by using the intrinsic symmetry of the benzene system to demonstrate (rigorously) that many of these integrals are zero. This is the subject of group theory. Group theory is used to exploit the symmetry of molecules to quickly gain insights into their properties, such as vibrations and molecular orbitals.


3.1: Chapter 3 Introduction
Food provides the body with the nutrients it needs to survive. Many of these critical nutrients are biological macromolecules, or large molecules, necessary for life. Different smaller organic molecule (monomer) combinations build these macromolecules (polymers). What specific biological macromolecules do living things require? How do these molecules form? What functions do they serve? We explore these questions in this chapter.
Contributors and Attributions
Remixed and/or curated from the following works:
Clark, M. A., Douglas, M., & Choi, J. (2018). 1.3.1 Introduction . In Biology 2e . OpenStax (CC BY 4.0; Access for free at https://openstax.org/books/biology-2e/pages/1-introduction ).


5.4: Text Effects
Learning Objectives
- Change text using text effects.
In addition to formatting changes we previously discussed in Fonts , you can also apply effects to text with the Text Effects option. This was known as WordArt in previous versions of Word. You can add shadows, bevels, reflections, and much more.
The Text Effects button is in the Font group of the ribbon.
The top options in the Text Effects menu have some pre-created styles to choose from.
The Text Effects menu also has the options Outline , Shadow , Reflection , and Glow .
Outline
Outline applies a border around the letters of the text.
Hover over each color to preview what the outline will look like. Click on the color to apply it. If you want to change the outline to a color not in the menu, pick More Outline Colors… for more options.
Use the weight option to change the thickness of the outline.
The Dashes option lets you make a dashed or dotted outline. There are many different kinds of dashes and dots to choose from.
Shadow
Shadow applies a shadow to the letters of the text. Hover over one of the A icons to preview the effects. Click on the A to apply that shadow style.
There are a lot of different shadow options.
The Shadow Options… option at the bottom of the menu allows you to customize the shadows even further by changing the color, transparency, blur, angle, and distance of the shadows.
- Color: The default shadow is black, but you can change the color to anything you want.
- Transparency: The higher the the transparency, the lighter the shadow.
- Blur: An increased blur makes the borders of the shadow more fuzzy, while a decreased blur makes the borders of the shadow more concrete.
- Angle: In real life, the direction of a shadow is determined by the angle of the light. The Angle option in the Shadow Options lets you change the direction of that imaginary light to alter the path of the shadow.
- Distance: The shadow can be very close, almost behind the letters, or it can be far away.
Reflection
Reflection reflects the letters of the text as if held up to a mirror. Hover over each option to preview, and click the option to apply it.
There are a couple variations of reflections to choose from. You can also select Reflection Options… to customize the transparency, size, blur, and distance of the reflection.
Glow
Glow applies a fuzzy colored shape around the letters of the text that makes the letters appear to be glowing. Hover over each option to preview, and click the option to apply it.
A glow can be any color. Go to More Glow Colors to choose a color not already visible in the menu. You can also select Glow Options… to customize the size and transparency.
Practice Question
Contributors and Attributions
- Text Effects. Authored by : Lumen Learning. License : CC BY: Attribution


Skip to main content
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5.0: Video Introduction to Chapter 5
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Introduction to the topics to be covered in Chapter 5: structures as trusses vs frames and machines; two-force members; methods of analysis for trusses and for frames and machines.
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5.1: Structures
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Definition of an engineering structure. The classification of structures into trusses and frames or machines.
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5.2: Two-Force Members
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Definition of two-force members, and how to identify them. The importance of two-force members in truss analysis problems.
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5.3: Trusses
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Definition of trusses, and their classification into plane and space trusses. Overview of the methods for analyzing trusses: the method of joints and method of sections.
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5.4: Method of Joints
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Using the method of joints, a process centering on the joints or connection points between the members, to solve for the unknown forces acting on members of a truss. Includes several worked examples.
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5.5: Method of Sections
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Using the method of sections, a process that involves breaking the truss down into sections to each be analyzed as a separate rigid body, to solve for unknown forces acting on members of a truss. Includes several worked examples.
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5.6: Frames and Machines
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Definition of a frame or machine as a structure with at least one non-two-force member. Distinguishing between frames and machines by structure rigidity.
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5.7: Analysis of Frames and Machines
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Steps of the process for analyzing frames and machines and determining the forces experienced by each component. Includes several worked examples.
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5.8: Chapter 5 Homework Problems
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2.10.1: Review Questions
Review Questions
From where on Earth could you observe all of the stars during the course of a year? What fraction of the sky can be seen from the North Pole?
2.
Give four ways to demonstrate that Earth is spherical.
3.
Explain, according to both geocentric and heliocentric cosmologies, why we see retrograde motion of the planets.
4.
In what ways did the work of Copernicus and Galileo differ from the views of the ancient Greeks and of their contemporaries?
5.
What were four of Galileo’s discoveries that were important to astronomy?
6.
Explain the origin of the magnitude designation for determining the brightness of stars. Why does it seem to go backward, with smaller numbers indicating brighter stars?
7.
Ursa Minor contains the pole star, Polaris, and the asterism known as the Little Dipper. From most locations in the Northern Hemisphere, all of the stars in Ursa Minor are circumpolar. Does that mean these stars are also above the horizon during the day? Explain.
8.
How many degrees does the Sun move per day relative to the fixed stars? How many days does it take for the Sun to return to its original location relative to the fixed stars?
9.
How many degrees does the Moon move per day relative to the fixed stars? How many days does it take for the Moon to return to its original location relative to the fixed stars?
10.
Explain how the zodiacal constellations are different from the other constellations.
11.
The Sun was once thought to be a planet. Explain why.
12.
Is the ecliptic the same thing as the celestial equator? Explain.
13.
What is an asterism? Can you name an example?
14.
Why did Pythagoras believe that Earth should be spherical?
15.
How did Aristotle deduce that the Sun is farther away from Earth than the Moon?
16.
What are two ways in which Aristotle deduced that Earth is spherical?
17.
How did Hipparchus discover the wobble of Earth’s axis, known as precession ?
18.
Why did Ptolemy have to introduce multiple circles of motion for the planets instead of a single, simple circle to represent the planet’s motion around the Earth?
19.
Why did Copernicus want to develop a completely new system for predicting planetary positions? Provide two reasons.
20.
What two factors made it difficult, at first, for astronomers to choose between the Copernican heliocentric model and the Ptolemaic geocentric model?
21.
What phases would Venus show if the geocentric model were correct?


17.6: Get Your Career Off on the Right Track
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- Last updated
- Save as PDF
Mark this section of the text with a permanent bookmark because you are going to want to refer back to it many times during the remainder of your college career. Yes, we are going to give you a road map to find, keep, and advance in that job that is perfect for you.
Think Positively
To be successful in life and in a career, you need to be positive. Positive thinking is making a conscious effort to think with an optimistic attitude and to anticipate positive outcomes. Positive behavior means purposely acting with energy and enthusiasm. When you think and behave positively, you guide your mind toward your goals and generate matching mental and physical energy.
Positive thinking and behavior are often deciding factors in landing top jobs: your first job, a promotion, a change of jobs—whatever career step you are targeting. That’s because the subconscious is literal; it accepts what you regard as fact. Follow these steps to form the habit of positive thinking and to boost your success:
- Deliberately motivate yourself every day. Think of yourself as successful, and expect positive outcomes for everything you attempt.
- Project energy and enthusiasm. Employers hire people who project positive energy and enthusiasm. Develop the habit of speaking, moving, and acting with these qualities.
- Practice this positive-expectation mindset until it becomes a habit.  Hiring decisions are influenced largely by this positive energy. The habit will help you reach your peak potential.
- Dwell on past successes. Focusing on past successes to remind yourself of your abilities helps in attaining goals. For example, no one is ever born knowing how to ride a bicycle or how to use a computer software program. Through training, practice, and trial and error, you master new abilities. During the trial-and-error phases of development, remind yourself of past successes; look at mistakes as part of the natural learning curve. Continue until you achieve the result you want, and remind yourself that you have succeeded in the past and can do so again. You fail only when you quit trying! 11
Take a Good Look at Yourself
Once you’ve developed a positive, “can do” attitude, the next step is to better understand yourself. Ask yourself two basic questions: “Who am I?” and “What can I do?”
Who Am I? This question is the start of self-assessment , examining your likes and dislikes and basic values. You may want to ask yourself the following questions:
- Do I want to help society?
- Do I want to help make the world a better place?
- Do I want to help other people directly?
- Is it important for me to be seen as part of a big corporation? Or do I prefer to be part of a smaller organization?
- Do I prefer working indoors or outdoors?
- Do I like to meet new people, or do I want to work alone?
Are you assertive? Assess your assertiveness by taking the quiz in Table 17.7 .
What Can I Do? After determining what your values are, take the second step in career planning by asking, “What can I do?” This question is the start of skill assessment , evaluating your key abilities and characteristics for dealing successfully with problems, tasks, and interactions with other people. Many skills—for instance, the ability to speak clearly and strongly—are valuable in many occupations.
Be sure to consider the work experience you already have, including part-time jobs while going to school, summer jobs, volunteer jobs, and internships. These jobs teach you skills and make you more attractive to potential employers. It’s never too early or too late to take a part-time job in your chosen field. For instance, someone with an interest in accounting would do well to try a part-time job with a CPA (certified public accountant) firm.
| Fun Self-Test—How Assertive Are You? | ||||
|---|---|---|---|---|
| Rate your level of agreement with the following statements using the scale below: | ||||
| Strongly Agree | Agree | Neither Agree nor Disagree | Disagree | Strongly Disagree |
|
||||
| See the scoring guidelines at the end of this chapter to obtain your score. |
Table 17.7
In addition to examining your job-related skills, you should also look at your leisure activities. Some possible questions: Am I good at golf? Do I enjoy sailing? Tennis? Racquetball? In some businesses, transactions are made during leisure hours. In that case, being able to play a skillful, or at least adequate, game of golf or tennis may be an asset.
It’s hard to like your job if you don’t like the field that you’re in. Most career counselors agree that finding work you’re passionate about is one of the critical factors behind career success. That’s why so many career counselors love all those diagnostic tools that measure your personality traits, skill levels, professional interests, and job potential.
The internet is virtually exploding with tests and assessments that you can take. Try, for example, http://www.self-directed-search.com . This test is based on the theory that people and work environments can be classified into six basic types: realistic, investigative, artistic, social, enterprising, and conventional. The test determines which three types best describe you, and it suggests occupations that could be a good match. The Keirsey Character Sorter ( http://www.keirsey.com ) is a first cousin of Myers-Briggs. It sorts people into four temperaments: idealists, rationals, artisans, and guardians. Like Myers-Briggs, it not only places you in an overall category, but it also offers a more detailed evaluation of your personality traits. To find a bunch of tests in one place, use a search engine and search “online personality tests.”
Understand What Employers Want
Employers want to hire people who will make their businesses more successful. The most desirable employees have the specific skills, transferable career competencies, work values, and personal qualities necessary to be successful in the employers’ organizations. The more clearly you convey your skills as they relate to your job target, the greater your chance of landing your ideal job. 13
Job-Specific Skills. Employers seek job-specific skills (skills and technical abilities that relate specifically to a particular job). Two examples of job-specific skills are using specialized tools and equipment and using a custom-designed software program.
Transferable Skills and Attitudes. Change is a constant in today’s business world. Strong transferable career skills are the keys to success in managing your career through change. The most influential skills and attitudes are the abilities to:
- Work well with people.
- Plan and manage multiple tasks.
- Maintain a positive attitude.
- Show enthusiasm.
Employers need workers who have transferable career competencies—basic skills and attitudes that are important for all types of work. These skills make you highly marketable because they’re needed for a wide variety of jobs and can be transferred from one task, job, or workplace to another. Examples include these:
- Planning skills
- Research skills
- Communication skills
- Human relations and interpersonal skills
- Critical thinking skills
- Management skills
- Project management skills
Take, for example, a construction supervisor and an accountant. Both must work well with others, manage time and specific tasks, solve problems, read, and communicate effectively—all transferable competencies. They both must be competent in these areas even though framing a house and balancing a set of financial information (the job-specific skill for each field, respectively) are not related. In every occupation, transferable competencies are as important as technical expertise and job-specific skills.
Find Your First Professional Job
The next step is landing the job that fits your skills and desires. You need to consider not only a general type of work but also your lifestyle and leisure goals. If you like to be outdoors most of the time, you might be very unhappy spending eight hours a day in an office. Someone who likes living in small towns may dislike working at the headquarters of a big corporation in Los Angeles, New York City, or Chicago. But make sure that your geographic preferences are realistic. Some parts of the country will experience much greater growth in jobs than others in the coming years.
According to recent research by Glassdoor, the online job listings and career site, the top 10 best cities for jobs in 2017 are:
- Pittsburgh, PA
- Indianapolis, IN
- Kansas City, MO
- Raleigh-Durham, NC
- St. Louis, MO
- Memphis, TN
- Columbus, OH
- Cincinnati, OH
- Cleveland, OH
- Louisville, KY 14
You might start answering the question “What will I do?” by studying the Occupational Outlook Handbook , published every two years by the U.S. Department of Labor ( https://www.bls.gov/ooh ) . The most recent Handbook edition projects job opportunities by industry through the year 2026. The Handbook is divided into 25 occupational clusters describing 325 job profiles (with a section on military careers). Among the clusters are education, sales and marketing, transportation, health, and social services. Each job description tells about the nature of the work, working conditions, required training, other qualifications, chances for advancement, employment outlook, earnings, related occupations, and sources of more information. Another good source of job information is the website for the National Association of Colleges and Employers ( http://www.naceweb.org ) . If you are a member of a minority group, you might want to check out https://www.blackcareernetwork.com or http://www.saludos.com .
Use the Internet to Find a Job
Today, most job searches are done online. Rarely do job seekers use “snail mail” to send a résumé to a potential employer. Therefore, you need to do your homework when it comes to creating a résumé and posting it to various websites, as well as sending it electronically to a specific company’s careers web page.
Let’s start with the résumé. There are thousands of job-related sites and millions of résumés on the internet. To break through the clutter, you must start with a great résumé—a written description of your education, work experience, personal data, and interests. There are plenty of online resources that can provide you with tips and actual templates to use when creating your résumé. For example, CollegeGrad ( https://collegegrad.com ) provides more than 100 preformatted templates for over 30 college majors on its website that you can use to tailor your résumé and highlight your specific skills and talents. 15 Of course, there are many other sources for creating a résumé, including the actual websites of most online job-listing services.
Once you have created an electronic résumé, you have several options when it comes to your job search. First, you can target specific companies where you would like to work. Then go to their corporate websites and look for a careers page on the website. For example, Google has an extensive careers section on its website that provides detailed information on how to apply to become a “Googler,” along with a section on what the company’s interview process entails and how Google makes hiring decisions. 16
You can also try posting your résumé on the top 10 most popular job websites. They are so large that they are worth checking out first. They tend to have more jobs listed, represent more companies, and have larger résumé databases, which attract even more companies. 17
- Indeed (www.indeed.com)
- Monster ( https://www.monster.com )
- Glassdoor ( https://www.glassdoor.com )
- CareerBuilder ( https://www.careerbuilder.com )
- SimplyHired ( https://www.simplyhired.com )
- JobDiagnosis (www.jobdiagnosis.com)
- Nexxt ( https://www.nexxt.com )
- ZipRecruiter ( https://www.ziprecruiter.com )
- USAJobs ( https://www.usajobs.gov )
The Multimedia Résumé
If you are going to become a computer programmer, web developer, graphics designer, artist, sculptor, singer, dancer, actor, model, animator, cartoonist, or anyone who would benefit by the photographs, graphics, animation, sound, color, or movement inherent in a multimedia résumé, then this résumé is for you. For most people, however, a multimedia résumé and personal home page on the internet aren’t necessary. Most internet service providers and commercial online services provide some space on their sites for subscriber home pages. 18
Getting Your Electronic Résumé into the Short Pile
Applicant tracking systems (ATSs) screen for keywords, which either reject your résumé or move it on to the short list. Your task is to use keywords that will produce as many “hits” as possible. Keywords tend to be more of the noun or noun phrase type (Total Quality Management, Walmart, Sales Manager) as opposed to power action verbs often found in traditional résumés (developed, coordinated, organized). Every occupation and career field has its own jargon, acronyms, and buzzwords. There are also general keywords that apply to transferable skills important in many jobs, such as teamwork, writing, and planning.
Use these tips for adding effective keywords to your résumé:
- The best source of keywords is the actual job listing, which is likely to contain many, if not all, of the keywords that an employer will use to search the résumé database.
- Include plenty of keyword nouns and noun phrases throughout your résumé. If you have a “Summary of Qualifications” section at the beginning of your résumé, try not to repeat verbatim the contents of this section.
- If you are applying for technical positions, you can list your skills, separating each noun or phrase by a comma.
- In some fields, a simple list of skills does not sufficiently describe the job seeker’s background. Where appropriate, include accomplishments, as well, but be sure to include enough keywords to satisfy the ATS searches. 19
There are several ways to determine what keywords are appropriate for your industry and job.
- Look through recent job postings online. Certain words will reappear consistently. Those are your “key” words.
- Make sure your résumé contains the keywords and concepts used in the particular job listing you are applying to.
- Talk to people in the career field you are targeting, and ask them what keywords are appropriate to the positions you are applying to.
- Research specific company websites that appeal to you in terms of getting a job with that specific organization, and review the “About Us” section. Try to use some of the key words the company uses to describe its corporate environment as part of your résumé descriptions. 20
- Visit professional association websites, and read the content carefully. Many of these are loaded with industry-related jargon that may be appropriate for your résumé.
If you are still in college , try to get at least one internship in the career field you’re targeting. Even if your internship lasts only a few weeks, you will significantly increase your keyword count to build a resume, not to mention gain valuable experience that will get the attention of hiring professionals. 21
I’ve Landed a Job Interview
If some of the companies you contacted want to speak with you, your résumé achieved its goal of getting you a job interview. Look at the interview as a chance to describe your knowledge and skills and interpret them in terms of the employer’s specific needs. To make this kind of presentation, you need to do some research on the company. A great place to start is the company’s own corporate website.
As you do your information search, you should build your knowledge in these three areas:
- General Information about the Occupational Field. Learn about the current and predicted industry trends, general educational requirements, job descriptions, growth outlook, and salary ranges in the industry.
- Information about Prospective Employers. Learn whether the organization is publicly or privately owned. Verify company names, addresses, products, or services (current and predicted, as well as trends); history; culture; reputation; performance; divisions and subsidiaries; locations (U.S. and global); predicted growth indicators; number of employees; company philosophies and procedures; predicted job openings; salary ranges; and listings of managers of your targeted department within the organization. Also learn about the competitors and customers.
- Information about Specific Jobs. Obtain job descriptions; identify the required education and experience; and determine prevalent working conditions, salary, and fringe benefits.
Interview Like a Pro
An interview tends to have three parts: icebreaking (about five minutes), in which the interviewer tries to put the applicant at ease; questioning (directly or indirectly) by the interviewer; and questioning by the applicant. Almost every recruiter you meet will be trying to rate you in 5 to 10 areas. The questions will be designed to assess your skills and personality.
Many firms start with a screening interview , a rather short interview (about 30 minutes) to decide whether to invite you back for a second interview. Sometimes screening interviews can take place online via Skype, FaceTime, or some other form of videoconferencing. Only about 20 percent of job applicants are invited back. The second interview is usually a half day or a day of meetings set up by the human resource department with managers in different departments. After the meetings, someone from the human resource department will discuss other application materials with you and tell you when a letter of acceptance or rejection is likely to be sent. (The wait may be weeks or even months.) Many applicants send follow-up letters in the meantime to show they are still interested in the firm.
For the interview, you should dress conservatively. Plan to arrive about 10 to 15 minutes ahead of time. Try to relax. Smile and make eye contact with (but do not stare at) the interviewer. Body language is an important communicator. The placement of your hands and feet and your overall posture say a good deal about you. Here are some other tips for interviewing like a pro:
-
Concentrate on being likable.
As simplistic as it seems, research proves that one of the most essential goals in successful interviewing is to be liked by the interviewer. Interviewers want to hire pleasant people others will like working with on a daily basis. Pay attention to the following areas to project that you are highly likable:
- Be friendly, courteous, and enthusiastic.
- Speak positively.
- Smile.
- Use positive body language.
- Make certain your appearance is appropriate.
- Make eye contact when you speak.
- Project an air of confidence and pride. Act as though you want and deserve the job, not as though you are desperate.
- Demonstrate enthusiasm. The applicant’s level of enthusiasm often influences employers as much as any other interviewing factor. The applicant who demonstrates little enthusiasm for a job will never be selected for the position.
- Demonstrate knowledge of and interest in the employer. “I really want this job” is not convincing enough. Explain why you want the position and how the position fits your career plans. You can cite opportunities that may be unique to a firm or emphasize your skills and education that are highly relevant to the position.
- State your name and the position you’re seeking. When you enter the interviewer’s office, begin with a friendly greeting and state the position you’re interviewing for: “Hello, Ms. Levine, I’m Bella Reyna. I’m here to interview for the accounting position.” If someone has already introduced you to the interviewer, simply say, “Good morning, Ms. Levine.” Identifying the position is important because interviewers often interview for many different positions.
- Focus on how you fit the job. Near the beginning of your interview, as soon as it seems appropriate, ask a question similar to this: “Could you describe the scope of the job and tell me what capabilities are most important in filling the position?” The interviewer’s response will help you focus on emphasizing your qualifications that best match the needs of the employer.
- Speak correctly. Grammatical errors can cost applicants the job. Use correct grammar, word choice, and a businesslike vocabulary, not an informal, chatty one. Avoid slang. When under stress, people often use pet phrases (such as you know ) too often. This is highly annoying and projects immaturity and insecurity. Don’t use just or only . “I just worked as a waiter.” Don’t say “I guess.” Avoid the word probably because it suggests unnecessary doubt. Ask a friend or family member to help you identify any speech weaknesses you have. Begin eliminating these speech habits now.
Also, you should avoid the following “disqualifiers” at all costs. Any one of these blunders could cost you your dream job:
- Don’t sit down until the interviewer invites you to; waiting is courteous.
- Don’t bring anyone else to the interview; it makes you look immature and insecure.
- Don’t smoke or bring a beverage with you.
- Don’t put anything on or read anything on the interviewer’s desk; it’s considered an invasion of personal space.
- Don’t chew gum or have anything else in your mouth; this projects immaturity.
- If you are invited to a business meal, don’t order alcohol. When ordering, choose food that’s easy to eat while carrying on a conversation.
- Don’t offer a limp handshake; it projects weakness. Use a firm handshake. 22
Select the Right Job for You
Hard work and a little luck may pay off with multiple job offers. Your happy dilemma is deciding which one is best for you. Start by considering the “FACTS”:
- Fit: Do the job and the employer fit your skills, interests, and lifestyle?
- Advancement and growth : Will you have the chance to develop your talents and move up within the organization?
- Compensation : Is the employer offering a competitive salary and benefits package?
- Training: Will the employer provide you with the tools needed to be successful on the job?
- Site: Is the job location a good match for your lifestyle and your budget?
A great way to evaluate a new location is through Homefair ( http://www.homefair.com ) . This site offers tools to help you calculate the cost of moving, the cost of living, and the quality of life in various places. The Moving Calculator helps you figure out how much it will cost to ship your worldly possessions to a particular city. The Relocation Crime Lab compares crime rates in various locations. The City Snapshots feature compares demographic, economic, and climate information for two cities of your choosing. The Salary Calculator computes cost-of-living differences between hundreds of U.S. and international cities and tells you how much you’d need to make in your new city to maintain your current standard of living.
Start Your New Job
No time is more crucial, and possibly nerve-racking, than the first few months at a new job. During this breaking-in period, the employer decides whether a new employee is valuable enough to keep and, if so, in what capacity. Sometimes the employee’s whole future with the company rides on the efforts of the first few weeks or months. Most firms offer some sort of formal orientation. But generally speaking, they expect employees to learn quickly—and often on their own. You will be expected to become familiar with the firm’s goals; its organization, including your place in the company; and basic personnel policies, such as coffee breaks, overtime, and parking.
Here are a few tips on making your first job rewarding and productive:
- Listen and learn: When you first walk into your new job, let your eyes and ears take everything in. Do people refer to one another by first names, or is the company more formal? How do people dress? Do the people you work with drop into one another’s open offices for informal chats about business matters? Or have you entered a “memo mill,” where anything of substance is put on email and talks with other employees are scheduled through their administrative assistants? Size up where the power lies. Who seems to most often assume a leadership role? Who is the person others turn to for advice? Why has that person achieved that position? What traits have made this person a “political leader”? Don’t be misled by what others say, but also don’t dismiss their evaluations. Make your own judgments based on what you see and hear. Effective listening skills help you learn your new job responsibilities quickly. Take the quiz in Table 17.8 to see if you are a good listener.
- Do unto others: Be nice. Nice people are usually the last to be fired and among the first to be promoted. Don’t be pleasant only with those who can help you in the company. Be nice to everyone. You never know who can help you or give you information that will turn out to be useful. Genuinely nice people make routine job assignments, and especially pressure-filled ones, more pleasant. And people who are dealt with pleasantly usually respond in kind.
- Don’t start out as a maverick: If every new employee tried to change tried-and-true methods to suit his or her whims, the firm would quickly be in chaos. Individual needs must take a back seat to established procedures. Devote yourself to getting things done within the system. Every manager realizes that it takes time for a new person to adjust. But the faster you start accomplishing things, the faster the boss will decide that you were the right person to hire.
- Find a great mentor: The leading cause of career unhappiness is working for a bad boss. Good jobs can easily be ruined by supervisors who hold you back. In contrast, your career will soar (and you will smile every day) when you have a great mentor helping you along the way. If you find a job with a super mentor, jump at the chance to take it.
| Fun Self-Test—Are You a Good Listener? | ||||
|---|---|---|---|---|
| Rate your level of agreement with the statements below using the following scale: | ||||
| Strongly Agree | Agree | Neither Agree nor Disagree | Disagree | Strongly Disagree |
|
||||
| See the scoring guidelines at the end of this chapter to obtain your score. |
Table 17.8
Moving Up
Once you have been on the job for a while, you will want to get ahead and be promoted. Table 17.9 offers several suggestions for improving your chances of promotion. The first item might seem a bit strange, yet it’s there for a practical reason.
So there you have it. Remember: it’s never too early to begin planning your career—the future is now.
| How to Move Up |
|---|
|
Table 17.9


6.3.2: Finding Solutions to Inequalities in Context
Lesson
Let's solve more complicated inequalities.
Exercise \(\PageIndex{1}\): Solutions to Equations and Solutions to Inequalities
- Solve \(-x=10\)
- Find 2 solutions to \(-x>10\)
- Solve \(2x=-20\)
- Find 2 solutions to \(2x>-20\)
Exercise \(\PageIndex{2}\): Earning Money For Soccer Stuff
-
Andre has a summer job selling magazine subscriptions. He earns $25 per week plus $3 for every subscription he sells. Andre hopes to make at least enough money this week to buy a new pair of soccer cleats.
- Let \(n\) represent the number of magazine subscriptions Andre sells this week. Write an expression for the amount of money he makes this week.
- The least expensive pair of cleats Andre wants costs $68. Write and solve an equation to find out how many magazine subscriptions Andre needs to sell to buy the cleats.
- If Andre sold 16 magazine subscriptions this week, would he reach his goal? Explain your reasoning.
- What are some other numbers of magazine subscriptions Andre could have sold and still reached his goal?
- Write an inequality expressing that Andre wants to make at least $68.
- Write an inequality to describe the number of subscriptions Andre must sell to reach his goal.
-
Diego has budgeted $35 from his summer job earnings to buy shorts and socks for soccer. He needs 5 pairs of socks and a pair of shorts. The socks cost different amounts in different stores. The shorts he wants cost $19.95.
- Let \(x\) represent the price of one pair of socks. Write an expression for the total cost of the socks and shorts.
- Write and solve an equation that says that Diego spent exactly $35 on the socks and shorts.
- List some other possible prices for the socks that would still allow Diego to stay within his budget.
- Write an inequality to represent the amount Diego can spend on a single pair of socks.
Exercise \(\PageIndex{3}\): Granola Bars and Savings
-
Kiran has $100 saved in a bank account. (The account doesn’t earn interest.) He asked Clare to help him figure out how much he could take out each month if he needs to have at least $25 in the account a year from now.
- Clare wrote the inequality \(-12x+100\geq 25\), where \(x\) represents the amount Kiran takes out each month. What does \(-12x\) represent?
- Find some values of \(x\) that would work for Kiran.
- We could express all the values that would work using either \(x\leq\underline{\quad}\) or \(x\geq\underline{\quad}\). Which one should we use?
- Write the answer to Kiran’s question using mathematical notation.
-
A teacher wants to buy 9 boxes of granola bars for a school trip. Each box usually costs $7, but many grocery stores are having a sale on granola bars this week. Different stores are selling boxes of granola bars at different discounts.
- If \(x\) represents the dollar amount of the discount, then the amount the teacher will pay can be expressed as \(9(7-x)\). In this expression, what does the quantity \(7-x\) represent?
- The teacher has $36 to spend on the granola bars. The equation \(9(7-x)=36\) represents a situation where she spends all $36. Solve this equation.
- What does the solution mean in this situation?
- The teacher does not have to spend all $36. Write an inequality relating 36 and \(9(7-x)\) representing this situation.
- The solution to this inequality must either look like \(x\geq 3\) or \(x\leq 3\). Which do you think it is? Explain your reasoning.
Are you ready for more?
Jada and Diego baked a large batch of cookies.
- They selected \(\frac{1}{4}\) of the cookies to give to their teachers.
- Next, they threw away one burnt cookie.
- They delivered \(\frac{2}{5}\) of the remaining cookies to a local nursing home.
- Next, they gave 3 cookies to some neighborhood kids.
- They wrapped up \(\frac{2}{3}\) of the remaining cookies to save for their friends.
After all this, they had 15 cookies left. How many cookies did they bake?
Summary
Suppose Elena has $5 and sells pens for $1.50 each. Her goal is to save $20. We could solve the equation \(1.5x+5=20\) to find the number of pens, \(x\), that Elena needs to sell in order to save exactly $20. Adding -5 to both sides of the equation gives us \(1.5x=15\), and then dividing both sides by \(1.5\) gives the solution \(x=10\) pens.
What if Elena wants to have some money left over? The inequality \(1.5x+5>20\) tells us that the amount of money Elena makes needs to be greater than $20. The solution to the previous equation will help us understand what the solutions to the inequality will be. We know that if she sells 10 pens, she will make $20. Since each pen gives her more money, she needs to sell more than 10 pens to make more than $20. So the solution to the inequality is \(x>10\).
Glossary Entries
Definition: Solution to an Inequality
A solution to an inequality is a number that can be used in place of the variable to make the inequality true.
For example, 5 is a solution to the inequality \(c<10\), because it is true that \(5<10\). Some other solutions to this inequality are 9.9, 0, and -4.
Practice
Exercise \(\PageIndex{4}\)
The solution to \(5-3x>35\) is either \(x>-10\) or \(-10>x\). Which solution is correct? Explain how you know.
Exercise \(\PageIndex{5}\)
The school band director determined from past experience that if they charge \(t\) dollars for a ticket to the concert, they can expect attendance of \(1000-50t\). The director used this model to figure out that the ticket price needs to be $8 or greater in order for at least 600 to attend. Do you agree with this claim? Why or why not?
Exercise \(\PageIndex{6}\)
Which inequality is true when the value of \(x\) is -3?
- \(-x-6<-3.5\)
- \(-x-6>3.5\)
- \(-x-6>-3.5\)
- \(x-6>-3.5\)
(From Unit 6.3.1)
Exercise \(\PageIndex{7}\)
Draw the solution set for each of the following inequalities.
1. \(x\leq 5\)
2. \(x<\frac{5}{2}\)
(From Unit 6.3.1)
Exercise \(\PageIndex{8}\)
Write three different equations that match the tape diagram.
(From Unit 6.1.3)
Exercise \(\PageIndex{9}\)
A baker wants to reduce the amount of sugar in his cake recipes. He decides to reduce the amount used in 1 cake by \(\frac{1}{2}\) cup. He then uses \(4\frac{1}{2}\) cups of sugar to bake 6 cakes.
- Describe how the tape diagram represents the story.
- How much sugar was originally in each cake recipe?
(From Unit 6.1.2)
Exercise \(\PageIndex{10}\)
One year ago, Clare was 4 feet 6 inches tall. Now Clare is 4 feet 10 inches tall. By what percentage did Clare’s height increase in the last year?
(From Unit 4.3.3)