Chapter 6 Section 2
catagen phase
a brief regression period where cell division ceases and the follicle undergoes involution
diffuse hair loss
a dramatic and distressing condition where hair is shed from all parts of the scalp
lanugo
a fine, unpigmented, downy hair that first appears on the fetus in the last trimester of development
hyponychium
a region of thickened stratum corneum over which the free nail edge projects
sebaceous glands
a small gland in the skin which secretes a lubricating oily matter into the hair follicles to lubricate the skin and hair
sweat glands
a small gland that secretes sweat, situated in the dermis of the skin
hair matrix
a structure immediately adjacent to the hair papilla in the hair bulb, houses keratinization
cerumen
a waterproof earwax secreted by ceruminous glands
eponychium
also know as the cuticle, a narrow band of epidermis extending from the margin of the nail wall onto the nail body
sweat pore
an indented region where there is an opening for the sweat gland on the epidermal surface
hair follicle
an oblique tube that surrounds the hair root
sebum
an oily, waxy secretion produced by sebaceous glands
male pattern baldness
causes loss of hair first from only the crown region of the scalp rather than uniformly
sweat
clear secretion released by exocytosis
cuticle
coats the hair, formed by a single cell layer around the cortex
apocrine sweat glands
coiled, tubular glands that release their secretion into hair follicles in the axillae, around the nipples, in the pubic region, and in the anal region
hair bulb
consists of epithelial cells and is a swelling at the base where the hair originates in the dermis
free edge
distal whitish part of the nail
hirsutism
excessive male pattern baldness in areas of the body that normally do not have terminal hair
nail folds
folds of skin that overlap the nail
hair
found almost everywhere on the body except the palms of the hands and palmar surfaces of the fingers, the sides and soles of the feet and toes, and portions of the external genitalia
cortex
hard structure that is formed by several layers of flattened cells closer to the outer surface of the developing hair
epidermal derivatives
includes the nails, hair, and exocrine glands of the skin, which are all derived from the epidermal epithelium
connective tissue root sheath
layer of a hair follicle that originates from the dermis
epithelial tissue root sheath
layer of a hair follicle that originates from the epidermis
nail bed
layer of epidermis which contains only the deeper, living cell layers of the epidermis
mammary glands
modified apocrine sweat glands
ceruminous glands
modified apocrine sweat glands located only in the external auditory meatus, where their secretion forms a waterproof earwax called cerumen
medulla
not found in all hair types, a remnant of the soft core of the matrix
nail body
pinkish part of the nail that covers a layer of epidermis that is called the nail bed
hair papilla
surrounded by epithelium at the base of the bulb, composed of a small amount of connective tissue containing tiny blood vessels and nerves
anagen phase
the active phase of growth where living cells of the hair bulb are rapidly growing, dividing, and transforming into hair
nail matrix
the actively growing part of the nail
merocrine sweat glands
the most numerous and widely distributed sweat glands
vellus
the primary human hair and is found on the upper and lower limbs
nail root
the proximal part of the nail embedded in the skin
thermoregulation
the regulation of body temperature by evaporation of fluid from the skin
telogen phase
the resting phase and is usually the phase where the hair is shed
shaft
the third portion of the hair that extends beyond the skin surface
lunula
the whitish semilunar area of the proximal end of the nail body
root
the zone of the hair extending from the bulb to the skin surface
arrector pili
thin ribbons of smooth muscle that extend from the hair follicle to the dermal papillae
alopecia
thinning of the hair
sweat gland duct
transports the secretion to the surface of the epidermis or into a hair follicle
terminal hair
usually coarser, pigmented, and longer than vellus
