ANATB - The Integumentary System II (Cutaneous glands, Hair, Nails)

what are the skin appendages and what do they do?

cutaneous glands, hair, hair follicles, and nails. maintain body homeostasis

the cutaneous glands are all

exocrine glands

how do exocrine glands release their secretions to the skin surface?

via ducts

the two groups of cutaneous glands and how they are formed:

sebaceous and sweat glands. formed by cells of the stratum basale but reside almost entirely in the dermis

where are sebaceous glands found, what is another name for them, and what is their product?

(also called oil glands) all over the skin except on palms and soles. they produce sebum

what is sebum and what does it do?

a mixture of oily substances and fragmented cells. a lubricant that keeps the skin soft and moist, also kills bacteria on skin

Physiology of acne, blackheads, whiteheads

acne: when sebaceous gland ducts are blocked by sebum, active infection of the sebaceous glands

blackhead: when sebaceous gland ducts are blocked by sebum, when the accumulated material oxidizes and dries, darkening

whitehead: when sebaceous gland ducts are blocked by sebum, if material does not dry or darken

also known as “cradle cap” in infants, caused by overactivity of the sebaceous glands, starts as pink raised lesions that form a brown-yellow crust of oily scales

seborrhea

where are sweat glands found, what is another name for them, and what are the 2 types

all of the body. sudoriferous glands. eccrine and apocrine

what do eccrine glands produce, what is their function? how does sweat reach skin?

sweat. inhibits the growth of bacteria, regulates heat. via a duct that opens externally (a sweat pore)

what does sweat contain?

water, salts, vitamin c, lactic acid, metabolic wastes

how is the production of sweat controlled?

by nerve endings in eccrine sweat glands that cause secretion of sweat when temperature is too high

where are apocrine glands found, what do they secrete?

axillary and genital areas (less numerous but larger). secretes water, salts, fatty acids, and proteins, empties into hair follicles. odorless, but can smell due to bacteria on the skin feeding on it

how are apocrine glands activated?

by nerve fibers during pain, stress, and arousal

what is hair? what are its functions?

a flexible epithelial structure of keratinized cells. guarding the head against bumps, shielding eyes via eyelashes, keep foreign particles out of respiratory tract, keeping warm

the part of the hair enclosed in a sheath called the hair follicle

the root

the part of the hair projecting from the scalp

the shaft

how does hair form?

by division of the nourished stratum basale cells from the hair bulb deep in the follicle, the cells are pushed away from the matrix, becoming keratinized and dying

what is the matrix?

the growth zone where hair begins to grow

what is the cuticle?

a single layer of cells that overlap like shingles and enclose the cortex, keeps hair from matting, most heavily keratinized region

hair pigment is made by _____ in the hair bulb

melanocytes

what are hair follicles?

compound structures of epithelial tissue and dermal connective tissue

what do hair papilla do?

provide bloody supply to the matrix in the hair bulb

what is a hair bulb?

the deepest part of the follicle

tiny, smooth muscles attach hair follicles to dermal tissue, when contracted, they cause hair to stand upright

arrector pili

the visible attached portion of a nail is called the ____. the ____ is embedded in the skin.

body, root

the borders of a nail are overlapping folds of skin called ____. the thick, outer edge is usually called the ____

nail folds, cuticle

the stratum basale of the epidermis that extends beneath the nail is the ___. the ____ is responsible for nail growth.

nail bed, nail matrix