5.3 - Functions of Skin

Question 1

Function - Protection

Answer 1

• From physical trauma
• Melanocytes: UV radiation
• Sebaceous gland secretions, langerhans cells, outer layer of dead cells all protect from invasion by pathogens

Question 2

Function - Regular water loss/gain

Answer 2

Keratinized cells- waterproof

Question 3

Function - Eliminate excess water and waste

Answer 3

Sweat glands: secrete water
Perspiration contains small amounts of salt, ammonia, uera, and other wastes

Question 4

Sensible perspiration

Answer 4

Sweat than can be felt

Question 5

Insensible perspiration

Answer 5

Sweat that occurs without awareness

Question 6

Function - Vitamin D

Answer 6

• Keratinocytes in skin produce Vitamin D when exposed to a little UV radiation
• Vitamin D goes to liver and kidneys to make Calcitriol
• Calcitriol regulates calcium uptake by digestive system (and metabolism of calcium and phosphorous)
• Calcium - phosphorous compounds are important for bone development and mineralization (strong and flexible)

Question 7

Rickets

Answer 7

Soft and deformed bones - not enough vitamin D

Question 8

Function - Gathers information

Answer 8

• Sensory receptors in skin send info to CNS
• Most numerous in fingers, touch important to sexual arousal

Question 9

Function - Temperature (warm)

Answer 9

• Muscles contract, ATP breaks, heat is released
• smooth muscle layer relaxes
• diameter of blood vessels increased (vasodilation)
• more blood moves to surface; heat is released; sweat glands activated

Question 10

Function - Temperature (cold)

Answer 10

• vasoconstriction - blood vessels dilate
• shivering - rhythmic muscular contractions
• arrector pili muscles attached to hair follicles create goosebumps (insulation with raised hair in animals)

Question 11

Necrosis

Answer 11

severely restricted blood flow from cold temps, results in frostbite

Question 12

Hyperthermia

Answer 12

Body temp above normal
seen as heat exhaustion, heat stroke, fever

Question 13

Heat exhaustion

Answer 13

• raised body temp but can sweat
• rapid water and electrolyte loss
• leads to heat stroke

Question 14

Heat stroke

Answer 14

• Raised body temp with inability to sweat (max 110 F), fatal

Question 15

Fever

Answer 15

• artificially raised normal temperature by immune system response or pathogen
• shivering increases temp, fever breaks and sweat brings set temperature back to normal

Question 16

Hypothermia

Answer 16

• Body temp below normal
• Uncontrollable shivering, incoherent speech, lack of coordination (90-95 F)
• Pulse rate slows, unconsciousness (80-90 F)
• Shallow breathing, shivering diminished, rigidity sets in - 50% mortality rate