Integumentary System: Oil and Sweat Glands

sweat glands

also called sudoriferous glands

all skin surfaces have sweat glands besides the nipples and external genetalia

2 types of sweat glands

eccrine(merocrine) sweat gland, and apocrine sweat gland

• contain myoepithelial cells

eccrine sweat gland

most numerous type, abundant on palms, soles and forehead

• ducts connect to pores

• function in thermoregulation

• their secretion is sweat

apocrine sweat gland

confined to axillary & anogenital areas

• secrete vicious milky or yellowish sweat that contains fats & proteins

• larger than eccrine glands

• begin to function at puberty

modified apocrine glands

cerimus glands- lining of external ear canal, secrete earwax

mammary glands- secrete milk

sebaceous (oil) glands

widely distributed, except for thick skin of palms & soles

most develop from hair follicles & secrete into hair follicles

• relatively inactive before puberty

• secrete sebum

  • oily holocrine secretion

  • bactericidal (bacteria killer)

  • softens hair/skin

Body temperature regulation

under normal resting body temperature, sweat glands produce about 500ml/day of unnoticeable sweat called insensible perspiration

sensible perspiration

designed to cool the body, if body temperature rises dilation of dermal vessels can increase sweat gland activity to produce 12L (3 gallons) of noticeable sweat

cold external environment

dermal blood vessels constrict

skin temperature drops to slow passive heat loss

cutaneous sensory receptors

part of nervous system, free nerve endings sense pain stimuli

• exteroceptors respond to stimuli outside the 

  • ex. temperature, touch

Blood Reservoir

skin can hold 5% of body’s total blood volume

• skin vessels can constrict to shunt blood to other organs such as exercising a muscle

excretion

sweating can cause sweat and water loos

skin can excrete ammonia, urea, and uric acid