Name 5 skin appendages.
What is the main function of body hair?
To sense insects before they bite or sting.
What are three reasons for having hair on your head?
Guards against head trauma, heat loss, and sunlight
What are flexible strands produced by hair follicles?
What is another word for hairs?
What are the chief regions of the hair?
The shaft and root
In the shaft, keratinization is ________, but in the root, keratinization is ________.
What are the three concentric layers of keratinized cells in a hair?
Medulla, cortex, cuticle
Which of the three is absent from fine hairs?
The _______ consists of large cells and airspaces.
What's the bulky layer surrounding the medulla?
The ________ is formed from a single layer of cells overlapping one another.
When the cuticle wears away at the tip of the hair shaft, allowing keratin fibrils in the cortex and medulla to frizz out. This is called a ________.
Hair pigment is made by _______ at the base of the hair follicle, and transferred to the cortical cells.
How is red hair colored?
By an iron-containing pigment called trichosiderin
When melanin production decreases, and air bubbles replace melanin in the hair shaft, the hair ________.
Turns gray (or white)
________ fold down from the epidermal surface into the dermis.
The deep end of the follicle expands to form a ________.
A knot of sensory nerve endings is called a ________.
Hair follicle receptor
A hair follicle receptor is also called a ________.
Hair root plexus
A hair follicle receptor or hair root plexus wraps around each _______.
________ is a nipplelike bit of dermal tissue that protrudes into the hair bulb.
What supplies nutrients to the growing hair and signals it to grow?
The wall of the hair follicle is composed of what 3 things?
The outer peripheral connective tissue sheath
The inner epithelial root sheath
A glassy membrane
The actively dividing area of the hair bulb that produces the hair is the ________.
The hair matrix originates from the _____ _____.
The two classifications of hair are:
The coarse, longer hair is ________, and pale, fine hair is _________.
Terminal hairs of puberty grow in response to the effects of ________.
What is excessive hairiness called?
Hair thinning and some degree of baldness is called ________.
________ is when the immune system attacks the follicles and the hair falls out in patches.
The white crescent of the nail is called:
The borders of the nails are overlapped by skinfolds called ________.
The fold that projects onto the body is the ________.
The thickened region beneath the free edge of the nail is the ________.
Sweat glands are also called ________.
How many sweat glands does the average person have?
Up to 3 million
What are the two types of sweat glands?
Eccrine sweat glands are also called _______.
Merocrine sweat glands
Sweat is 99% ________.
Water, salts, vitamin C, antibodies, dermcidin, and traces of metabolic waste.
Sweat is _______, with a Ph between ___ and ___.
4 and 6
________ glands begin functioning at puberty and play little role in maintaining a constant body temp.
Modified apochrine glands found in the lining of the external ear canal
Oil glands are also called ________ glands.
True or False:
Sebaceous glands are also found in the thick skin of the palms and soles.
Sebaceous glands are found all over the body except the thick skin. Eccrine glands are particularly abundant on the palms and soles.
Sebaceous glands produce an oily substance called ________.
Overactive sebaceous glands can cause ________ in infants. This is also called _______.