2.6: accessory structures: nails & glands

composition

-hard keratin, no melanocytes

-external: nail plate

-nail bed: underlying nail plate

-nail matrix: site of nail growth

functions

protection, object manipulation

glands

groups of modified epithelial cells located in dermis

exocrine glands & types of glands

release non-hormonal secretions secretions

-sweat

-sebaceous

*eccrine sweat glands

-abundant throughout body

-sweat secreted into skin surface via ducts

-99% water, solutes & bactericidal liquid

-thermoregulation

-emotional sweating begins on palms & spreads elsewhere

apocrine sweat glands

-only in genital regions

-nonfunctional until puberty

-sweat released through hair follicles

-bacterial activities on surface with sweat produce odor

ceruminous glands: modified sweat

-found in lining of ear canal

-secrete cerumen for lubrication & protection

mammary glands

-found in adipose tissue of breasts

-secrete milk: proteins, lipids, carbs

-present in males & females

-develop only during pregnancy & lactation

sebaceous glands (structurally different from other glands)

-most numerous on face & scalp

-secrete into hair follicle

-largely inactive until puberty

-secrete sebum: lubricates/ waterproofs skin & hair, bactericidal properties