Integumentary System Accessory Structures Flashcards
hair
- non-living (keratin + cuticle)
- around 2.5 million hairs on most of body
- 25% of hair on head
hair growth
from hair follicles in epidermis down into dermis and extends above skin surface
hair functions
- protect from UV damage
- help cushion light impact
- reduce insect and pathogen entry
- important as sensory receptors
follicle
surrounded by connective tissue then sensory neuron
nails
keratinised epidermal cells forming a clear, solid covering over the distal ends of digits
nail growth
nail body grows from nail root and extends over nail bed
nail functions
- protects exposed tips of digits
- helps digit withstand distortion
- allows manipulation and grip of small objects
- allows scratching and grooming of the body
sweat glands
- apocrine
- merocrine
apocrine sweat glands
- pubic & axillary regions, around nipples
- activated at puberty
- secrete sweat into hair follicles
- odour since bacteria use it for nutrition
merocrine sweat glands
- secrete onto skin surface
- more numerous and widely distributed
- palms and soles have highest numbers
merocrine sweat composition
water, electrolytes, organic compounds, and an antibiotic peptide that works in high salt conditions
merocrine sweat gland functions
- cools skin surface
- excrete water, electrolytes, etc
- dilutes harmful chemicals on skin
- discourages microbrial growth
sebaceous glands
- oil glands
- sebum
- inhibits bacterial growth
- lubricates and protects keratin of hair
oil glands
discharge oily, lipid secretion (sebum) into hair follicles and onto skin
sebum
comprised from triglycerides, cholesterol, proteins, electrolytes
sebaceous follicles discharge locations
directly onto epidermal surface to lubricate skin surface, located on face, back, chest, nipples and external genitalia
