define the terms skeletal muscle fiber, motor unit skeletal muscle twitch electrical stimulus and latent period
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"""Define The Terms Skeletal Muscle Fiber Motor Unit Skeltal Muscle Twitch"" Essays and Research Papers" Define the terms skeletal muscle fiber, motor unit, skeletal muscle twitch, electrical stimulus, and latent period. Skeletal muscle fibers are the individual cells that are bound together in fascicles. Many fascicles are bound together to make a muscle. A motor unit consists of a motor neuron and all of the muscle fibers in innervates. A skeletal muscle twitch is a mechanical response to a single action potential. During this experiment, we used an electrical stimulus to mimic the contractions of skeletal muscles. It is done in vitro to produce in vivo results.
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- A muscle fiber contracts in an all-or-none fashion. There is a slight latent period that occurs between when the stimulus arrives at the muscle and when the muscle contracts. Muscles will add motor units to a contraction, increasing the overall force of contraction.When a person is fully at rest, none of her muscles are contracting.here is a slight latent period that occurs between when the stimulus arrives at the muscle and when the muscle contracts. Muscles will add motor units to a contraction, increasing the overall force of contraction. When a person is fully at rest, none of her muscles are contracting.
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- Muscle fibres are cylindrical, and multinucleated. Muscle fibers are in turn composed of myofibrils. The myofibrils are composed of actin and myosin filaments, repeated in units called sarcomeres, the basic functional units of the muscle fiber. The sarcomere is responsible for the striated appearance of skeletal muscle, and forms the basic machinery necessary for muscle contraction. The term muscle refers to multiple bundles of muscle fibers called fascicles. All muscles also contain connective tissue arranged in layers of fasciae.
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Structure and Function of Skeletal Muscle The contraction of a muscle fiber is triggered by an action potential conducting over plasma membrane of the muscle fiber. The action potential conducts from the surface of the muscle fiber into the interior via transverse tubules (T tubules).These long tubes are continuous with the plasma membrane.t is through this connective tissue that the force generated by the individual cells is transmitted to the bone. A group of muscle cells are bundled together by collagen to form a fascicle. Since muscle cells are elongated and cylindrical, each muscle cell is usually called a muscle fiber.
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Cell Biology@ Yale Contraction of Smooth Muscle. Myosin filaments in smooth muscle are also activated by increases in cytosolic calcium but by a different mechanism than in skeletal/cardiac muscle. Seven transmembrane receptors trigger signaling cascades that lead to increases in cytosolic calcium. Contrast the organization of myosin and actin filaments in smooth muscle with skeletal/cardiac muscle. 2  List the events from release of acetylcholine to contraction of sarcomeres in skeletal muscle cells.
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"""Define The Terms Skeletal Muscle Fiber Motor Unit Skeltal Muscle Twitch"" Essays and Research Papers" made up of fascicles (bundle of cells) covered in perimysium. made up of muscle fibers (cells) covered in endomysium. myofibrils (made of molecular motors) make up each muscle fiber and sarcomeres are contained in each myofibril. blood vessels line in between the connective tissue coverings in between the fascicles. sarcolemma is the cell membrane of muscles with invaginations (t tubules) that go into the cells.
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Muscle force production and transmission The period between stimulus arrival and muscle force increase and shortening is known as the latent period (figure 3.1). Muscle activation involves a complex sequence of events that can be considered at two levels: (1) individual muscle fibers and (2) the entire muscle.
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- Like a single neuron, a single muscle fiber will not respond to any stimulus impulse that is below threshold. Any single stimulus impulse above threshold will produce a contraction, or single twitch (see Fig. 1), of the same strength. There are no gradations in the strength of the muscle response for a single twitch. Muscles outside the laboratory, however, do not use single twitches to produce motion. A muscle twitch is usually divided into three phases: 1) the latent period; 2) the contraction period; 3) the relaxation period (see Figure 4).
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What is the contraction phase (of muscles) and what events are occuring? Best Answer: A muscles contraction (also known as a muscle twitch or simply twitch) occurs when a muscle fibre generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten or remain the same. Though the term 'contraction' implies a shortening or reduction, when used as a scientific term referring to the muscular system contraction refers to the generation of tension by muscle fibers with the help of motor neurons. Contraction is will happen once a muscle is stimulated by a threshold stimulus. Muscle Contraction. 1. The distal end of a motor neuron releases acetylcholine. 2. Acetylcholine diffuses across the gap at the neuromuscular junction. 3.
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PhysioEx 3 Latent period: period of time that elapses b/w the generation of an AP in a muscle cell & the start of a contraction. Contraction phase: a period of time that starts at the end of the latent period & ends when muscle tension peaks. Relaxation phase: period of time from peak tension until the end of muscle contraction.
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Contraction and Relaxation Steps in the contraction and relaxation of skeletal muscles: 1  Nerve impulse, or electrical signal, travels down the nerve to the terminal to cause the release of the neurotransmitter acetylcholine (ACh). 2  ACh diffuses across the neuromuscular junction and binds to the receptor sites.
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- The muscle twitch:the response of whole muscle to a single threshold. stimulus. a. Threshold:the minimum stimulus necessary to cause slightest visible. motion of the muscle. b. Myogram: the recording of a muscle twitch. 1) Latent period: a few msec. 2) Period of contraction: 30 msec.
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- Introduction Muscle tissues share four basic properties:  Excitability: the ability to respond to stimulation Skeletal muscles normally respond to stimulation by the nervous system.Cardiac and smooth muscles respond to the nervous system and circulating hormones.uscle Contraction Contracting muscle fibers exert a pull, or tension, and shorten in length.Caused by interactions between thick and thin filaments in each sarcomereTriggered by presence of calcium ionsContraction itself requires the presence of ATP.
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- A muscle cell never contracts partially. Once the stimulus reaches the depolarization threshold, the muscle membrane depolarizes and the cell (fiber) contracts. The all or none response is the same for nerves cells, where if a threshold stimulus for depolarization is reached, the membrane depolarizes. Any increase in the intensity of the stimulus does not result in a greater response. Either a muscle or nerve cell depolarizes completely or not at all..so all or none at all. In this way, a muscle fiber always contracts maximally, even if the contraction is initiated by a large electrical shock rather than a motor neuron signal..the contraction is the same intensity, either maximal or nonexistent.
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Exercise 2: Skeletal Muscle Physiology: Activity 1: The Muscle Twitch and the Latent Period Lab Report Exercise 2: Skeletal Muscle Physiology: Activity 1: The Muscle Twitch and the Latent Period Lab Report Pre-lab Quiz Results You scored 100% by answering 5 out of 5 questions correctly. 1. Skeletal muscles are connected to bones by You correctly answered: b. tendons.
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- Muscle contraction in initiated by an action potential sent from the brain or spinal cord to the axon terminal of a motor neuron.onfidence votes 60. Muscle contraction in initiated by an action potential sent from the brain or spinal cord to the axon terminal of a motor neuron. Calcium then goes into the axon terminal which causes the release of the neurotransmitter acetylcholine which binds to receptors on the plasmalemma.
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latent period latent period. (also called reaction time) the first period of a simple muscle contraction, being the interval between the stimulus being applied and the contraction occurring, usually around 0.01 seconds. See Fig. 204 .
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Chapter 9: Muscular System List the sequence of events involved in skeletal muscle fiber contraction beginning with the necessary motor impulse initiated by the brain. Explain how and why a contracted muscle relaxes. Name the three pathways that regenerate energy/ATP in muscle cells.
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- The contraction produced can be described as a twitch, summation, or tetanus, depending on the frequency of action potentials. In skeletal muscles, muscle tension is at its greatest when the muscle is stretched to an intermediate length as described by the length-tension relationship.
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Motor Units Such a contraction is called a twitch. Thus, each motor unit is either relaxed or each presynaptic action potential causes an action potential in all of the muscle fibers of the motor unit, causing them all to contract at once.
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Physiolab 9.0 Exercise 2 3. Describe the process of excitation-contraction coupling in skeletal muscle fibers. ACH is released at the end-plate potential. ACH diffuses into the sarcolemma, attaches to the receptors in the motor end plate and causes a change in the ions permeability that creates graded depolarization of the end-plate potential.
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"""Define The Terms Skeletal Muscle Fiber Motor Unit Skeltal Muscle Twitch"" Essays and Research Papers" SHEET EXERCISE 2 Skeletal Muscle Physiology NAME: Jasmine Young LAB TIME/DATE: 1. Define each of the following... terms: • motor unit - A motor unit consists of a motor neuron and all of the muscle fibers it innervates. • twitch - Skeletal Muscle twitch is the mechanical response to a single action potential.
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- Thick and thin filaments are organized into contractile units called sarcomeres. A sarcomere extends from one Z line to the next and represents the fundamental unit of muscle contraction. From Copstead, 1995.
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- The axons of somatic motor neurons synapse with skeletal muscles. All somatic motorneurons release the neurotransmitter acetylcholine (ACh) from their synaptic knobs. ACh isalways excitatory at synapses with skeletal muscle fibers; a synapse between a motor neuron anda muscle fiber is called a neuromuscular junction.
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Muscle contraction Skeletal muscle contractions can be broadly separated into twitch, summation, and tetanic contractions. In a twitch contraction, a single action potential, whether from a motor neuron or from within the muscle, causes the muscle fiber to produce a single contraction and relaxation cycle called a twitch.uscle contractions can be described based on two variables: length and tension. A muscle contraction is described as isometric if the muscle tension changes but the muscle length remains the same. In contrast, a muscle contraction is isotonic if muscle length changes but the muscle tension remains the same.