Keratin & Cellular Properties
The key protein produced in large amounts in the stratum granulosum that makes skin water-resistant.
What is keratin?
The visible part of the hair on the surface of the skin consisting of dead, keratinized cells.
What is the hair shaft?
The oily lipid secretion produced by sebaceous glands to lubricate hair and inhibit bacteria.
What is sebum?
The dense mass of dead, keratinized cells that forms the visible body of the nail.
What is the nail body?
The blood vessel activity that causes light skin to flush red during inflammation, excitement, or heat.
What is vasodilation (or dilation of dermal blood vessels)?
The outermost epidermal layer consisting of 15–30 layers of dead, flattened, keratinized cells.
What is the stratum corneum?
The smooth muscle attached to hair follicles that contracts to pull hairs vertical and produce goosebumps.
What is the arrector pili muscle?
The condition caused when sebaceous ducts become blocked, accumulating secretions and trapping bacteria.
What is acne?
he pale, white crescent-shaped area located near the root of the nail.
What is the lunula?
The vascular response that causes the skin to turn pale when frightened or cold.
What is vasoconstriction (or constriction of dermal blood vessels)?
The spinous epidermal layer located immediately superficial to the stratum germinativum where cells continue to divide.
What is the stratum spinosum?
The three concentric layers of a hair from outside to inside.
What are the cuticle, cortex, and medulla?
The two areas on the human body where sebaceous glands are completely absent.
What are the palms of the hands and soles of the feet?
The structural term for the nail cuticle formed by an extension of the stratum corneum.
What is the eponychium?
Four distinct sensory stimuli detected and relayed by skin sensory receptors.
What are touch, pressure, pain, and temperature?
Four animal structures formed by combinations of keratin besides hair and nails.
What are horns, hooves, feathers, and baleen plates?
The root cause of white hair in aging individuals.
What is a lack of pigment production combined with air bubbles within the hair shaft?
The sweat glands that discharge secretions directly onto the skin surface to regulate body temperature.
What are merocrine (or eccrine) sweat glands?
The exact site where nail production occurs beneath an invisible fold of epithelium.
What is the nail root?
Three essential functions performed by nerve fibers in the dermal layer.
What are controlling blood flow, adjusting gland secretions, and monitoring sensory receptors?
The epidermal layer where cells cease cell division and begin manufacturing large amounts of keratin.
What is the stratum granulosum?
The average daily growth rate of hair and the duration range of its active growth phase.
What is 0.3 mm per day and 2 to 7 years?
The locations where apocrine sweat glands empty into hair follicles and the reason their secretions produce odor.
What are the armpits, nipples, and groin, and because bacteria feed on the secretions?
The underlying epidermal layer covered by the nail body, and the layer beneath the free edge.
What are the nail bed and the hyponychium?
The small structure at the base of the hair follicle that houses capillaries and nerve endings to feed growing hair.
What is the hair papilla?