Ch.3 Physiology & Histology Of The Skin (Six Primary Functions)

Question 1

What are the 6 primary functions of the skin?

Answer 1

PHASES

PROTECTION
HEAT REGULATION
ABSORPTION
SENSATION
EXCRETION
SECRETION

Question 2

Describe protection function: Acid Mantle

Answer 2

•Acid mantle ph of 5.5 is a hydropilidic water/oil) film protecting from virus/bacteria & part of the barrier function
•Barrier function is skins mechanism to protect from irritation & water loss on skin surface by evaporation aka TRANSepidermal water loss.
•lipids are protective oils, contribute to barrier function & are part of the intercellular matrix (fluid)
•Damage to barrier layer= SAD
sensitivity, aging, dehydration,

Question 3

Describe protection function: Melanocytes

Answer 3

•cells that produce pigment & protect from UV rays
•Melanocytes produce pigment granules called melanosomes
•melanosomes produce a protein called melanin
•melanin travels up from basal cell layer of the stratum germinativum through dendrites (finger like projections)
• UV can damage DNA in melanocytes & cause skin cancer

Question 4

Describe protection function: Repair

Answer 4

•Skin can self heal allowing protection from infection & damage from injury
•through blood clotting & hyperproduction of cells skin can restore normal thickness
•epidermal growth factor (a hormone) stimulates skin cells to reproduce & heal
•proteins & peptides trigger fibroblasts (cell stimulators) & cells to rejuvenate .
•cells in immune system are protective components

Question 5

Describe HEAT REGULATION function:

Answer 5

•average body temp is 98.6
•climate changes = skin adjusts
•Body Thermoregulation methods:
RIPE (radiation, insulation, perspiration, evaporation)
•sweat to prevent overheating ( release sweat through glands) then evaporation on skins surface to cool
•blood flow & vessel dilation assist in cooling
•constriction of blood vessels & decreased blood flow =protection from cold
•fat layer helps insulate & warm body
•shivering is an automatic response & aids in warming
•ARRECTOR PILI MUSCLES attached to hair follicles contract, straightening hair (goosebumps) creating air pockets under hair

Question 6

Describe ABSORPTION function:

Answer 6

•Absorption of chemicals, hormones, moisture & oxygen is necessary for skin health
•Vitamin D is synthesized & produced when exposed to sun
•through cells, hair follicles & sebaceous glands the skin absorbs products
•molecular size of product determines absorption level(lipid soluble absorb better).
•absorption is through follicle walls , sebaceous glands , INTERcellular (between) or TRANScellular (accross)
•small molecules with permeable cell walls penetrate the cells. Large cells with non permeable =absorbed through glands
•lipid-soluble =oil

Question 7

Describe SENSATION function:

Answer 7

•sensory nerve fibers are most abundant in fingertips & are the most sensitive parts of the body.

•sensory nerves sends informational impulse and motor nerve sends response impulse

Question 8

Describe EXCRETION function:

Answer 8

•sudoríferos gland- excretes perspiration
(Sweat gland) prevents overheating
•liver & kidney detox
•heavy sweating Can cause dehydration & loss of mineral balance
•sweat is part of the acid mantle

Question 9

Describe SECRETION function:

Answer 9

•sebum- oily, protects hair and skin & lubricates hair/skin, slows evaporation of water (TRANSepidermal water loss) & maintains water levels
•sebaceous glands- (oil glands) are an appendage (attached) to sebum producing follicles
• skin is 50-70% water
•Emotional stress & hormone imbalance Can can stimulate sebum production causing acne

Question 10

What are pores and follicles?

Answer 10

Pores- tubelike openings for sweat glands on the epidermis (sweating)

Follicles- tubelike depressions with oil glands attached (sebum secretion)