While deep tendon reflexes involve a single connection between afferent and efferent neurons (i.e., a monosynaptic reflex), the expression of a deep tendon reflex requires additional spinal connections.
Determining how many hairs are lost from the average human body in a typical day can be difficult, however. Some experts believe daily hair loss of between 50 and 100 hairs can be considered normal, while others say up to 200 hairs may be lost on average per day. Anything above the 200 hairs per day mark, however, should be considered excessive. There are many myths surrounding what is normal in regards to hair loss. Within the standard measurement, the rate of hair loss can vary based on your age as well as genetic influences.
The hair you can see is actually a string of dead keratin cells. The average adult head has about 100,000 to 150,000 hairs and loses up to 100 of them a day; finding a few stray hairs on your hairbrush is not necessarily cause for alarm. At any one time, about 90% of the hair on a person's scalp is growing. Each follicle has its own life cycle that can be influenced by age, disease, and a wide variety of other factors. This life cycle is divided into three phases: