2.Integumentary system Flashcards
Identify 3 layers of skin
epidermis, dermis and subcutaneous (hypodermis)
Describe epidermis
-most superficial layer
-no blood vessels or nerve endings
-melanocytes found
-no hair
Describe dermis
contains blood vessels, sensory nerves, sweat glands & ducts, sebaceous gland, hair and arrestor pili muscle
Describe subcutaneous layer
continuous layer of tissue (adipose and areolar)
Function of subcutaneous layer
insulate, store energy and shock absorb
Outline vitamin D production
skin exposed to UV light
UV light reacts with enzymes
pre vitamin D forms which is rearranged into vitamin D
Identify functions of integumentary system
Protection
Absorption
Sensation
Temperature regulation
Excretion
Vitamin D formation
(PASTED)
How does integumentary system carry out ‘Protection’
intact barrier prevents against invasion by pathogens, UV, mild trauma and chemicals
How does integumentary system carry out ‘Absorption’
limits absorption of drugs and toxic chemicals eg Mercury
How does integumentary system carry out ‘Sensation’
-nerve endings in the dermis are sensitive to stimuli eg nocioreceptors
How does integumentary system carry out ‘Temp regulation’
regulates body temp via vasodilation and constriction/sweat glands and piloerection
describe vasodilation
Increase diameter of blood vessels, increase blood flow increased heat loss by radiation
describe vasoconstriction
Decreased diameter of blood vessels, decreased blood flow decreased heat loss by radiation
How do sweat glands regulate body temperature
Sweat released onto skin surface, increased heat loss by evaporation
How does piloerection regulate body temp
Erector pili muscle cause the erection of hairs, trapping air molecules on the surface of the skin, creating insulating barrier and decreasing heat loss by radiation
piloerection /
goosebumps
How does integumentary system carry out ‘Excretion’
Sodium chloride, sweat, urea and garlic can be excreted via skin
Sudoriferous glands =
sweat glands
Apocrine means
open to hair follicle
Eccrine means
open to skin
what are arrector pili muscle
smooth muscle fibers
Identify functions of hair
regulate body temp
protect eg against sun/trap pathogens eg nasal hairs
provide sensory information
Describe structure of hair
keratin filaments with a root and shaft attached to arrestor pili muscle
How does hair have a protective function
against sunburn, debris, dust and foreign particles eg eyelashes, scalp, nose
How does hair provide sensory information
hairs in vestibular system of inner ear detects head movements re:position and balance
structure of nails
hard keratin plates that protect tips of fingers & toes
3 parts of nail are
eponychium
hyponychium
perionychium
Outline functions of nail
-serves as protective plates to help prevent scraping/cutting of fingers in envy activities
-enhance sensation
What are sebaceous glands
-attach to hair and secrete sebum
Contrast two types of sweat glands
Eccrine-most numerous/smaller/water and NaCl
Apocrine-armpits,scrotum,anus,labia/odour
Function of sebaceous glands
secrete oil/SEBUM
-keeps hair soft and pliable
-acts as anti fungal and antibacterial
-lubricates skin/maintains hydration of skin
what are ducts and pores
ducts are the pathway for sebum whereas pore is the opening to skin
