6.3 - Cutaneous Glands

types of skin glands

eccrine sweat glands, apocrine sweat glands, sebaceous glands, ceruminous glands, and mammary glands

apocrine sweat glands (location)

groin, anal region, axilla, areola, and, in mature males, the beard area

apocrine sweat glands (distinguishing characteristics)

ducts lead into nearby hair follicles rather than directly to the skin surface, and secretory parts have much larger lumen than those of an eccrine gland

apocrine sweat glands

scent glands that respond especially to stress and sexual stimulation, are not active until puberty, enlarge and shrink in phase with the menstrual cycle, and secrete sex hormones

sex hormones

chemicals that exert subtle effects on the sexual behavior and physiology of other people

bromhidrosis

disagreeable body odor

eccrine sweat glands (location)

widely distributed over the entire body, but are especially abundant on the palms, soles, and forehead

eccrine sweat glands (merocrine sweat glands)

simple tubular glands with a twisted coil in the dermis or hypodermis, and an undulating or coiled duct leading to a sweat pore on the skin surface, which is lined by a stratified cuboidal epithelium in the dermis and by keratinocytes in the epidermis

eccrine sweat glands (function)

cooling the body

myoepithelial cells

specialized cells found amid the secretory cells at the deep end of both apocrine and eccrine sweat glands

myoepithelial cells (function)

have contractile properties similar to those of smooth muscle that are stimulated by the sympathetic nervous system particularly under conditions of overheating, nervousness, or arousal

insensible perspiration

perspiration that evaporates about as fast as it is produced, so it goes unnoticed

diaphoresis

copius sweat is produced and notably wets the skin in conditions like heat, exercise, and circulatory shock

perspiration

secretion that is 99% water and has a pH ranging from 4 to 6

cutaneous transpiration

process in which water diffuses between the keratinocytes and evaporates from the skin surface

sebaceous glands

flask-shaped holocrine glands with short ducts that typically open into a hair follicle, although some open directly onto the skin surface

sebaceous glands (function)

secrete sebum

sebum

oily secretion that consists of broken-down cells that are replaced by mitosis at the base of the gland

sebum (function)

keeps the skin and hair from becoming dry, brittle, and cracked

ceruminous glands

coiled, simple tubular, modified apocrine glands found only in the external ear canal with ducts leading to hair follicles or the skin surface of the ear canal

cerumen (earwax)

composed of sebum, dead epidermal cells, and the yellow, waxy secretion of ceruminous glands

cerumen (function)

keeps the eardrum pliable, waterproofs the ear canal, kills bacteria, and coats the guard hairs of the ear, making them sticky and more effective in blocking foreign particles from entering the canal

mammary glands

milk-producing modified apocrine sweat glands that develop within the female breast during pregnancy and lactation, produce a richer secretion, and channel it through ducts to a nipple for efficient conveyance to the offspring