Lecture 7 - Integument Physiology 1

Question 1

T/F: at every body orifice, the skin is continuous with the mucous membrane located there

Answer 1

True

Question 2

What are the 3 layers of the skin

Answer 2

1 - Epidermis
2 -Dermis
3 - Hypodermis

Question 3

what are the 4 distinct cell types within the epidermis

Answer 3

1 - Keratinocytes
2 - melanocytes
3 - Langerhans cells
4 - Merkel cells

Question 4

Keratinocytes

Answer 4

specialized epithelial cell

Question 5

Melanocytes

Answer 5

pigment cells

Question 6

Langerhans cells

Answer 6

specialized macrophage (local immunity)

Question 7

Merkel cells

Answer 7

specialized sensory cells

Question 8

What regulatory role does the dermis play

Answer 8

regulation of cell growth, proliferation, adhesion, migration, differentiation, and wound healing

Question 9

What insoluble fibers are found in the dermis

Answer 9

collagen, elastin, macromolecules

Question 10

T/F: many of the functions of the skin are performed in the dermis

Answer 10

True

Question 11

For some functional reasons, there is no subcutis in some areas. what are these areas?

Answer 11

Lip, cheek, eyelid, external ear, anus

Question 12

the hypodermis is 90% ______

Answer 12

triglyceride

Question 13

What are the 6 functions of the skin

Answer 13

1 - Physical barrier
2 - Immune defense against external threats
3 - metabolic functions
4 - Indicator
5 - Sensory perception
6 - Thermoregulation

Question 14

Physical barrier

Answer 14

Exclusion of external injurious agents and retention of necessary water, electrolytes, etc.

Question 15

Immune defense against external threats

Answer 15

external microorganisms with antimicrobial and antifungal properties

Question 16

metabolic functions

Answer 16

storage of nutrients and fluid
excretion of waste byproducts
vitamin D metabolism

Question 17

what is the active form of vitamin D

Answer 17

calcitriol (1,25 hydroxyvitamin D)

Question 18

Summarize Vitamin D metabolism

Answer 18

1 - Vitamin D3 is formed from pro-D3 via pre-D3 on exposure to sunlight
2 - binding protein in plasma translocates D3 into circulation
3 - D3 is hydroxylated in the liver
4 - hydroxylated again in the kidneys to the final product

Question 19

Indicator

Answer 19

general health or internal disease
camouflage
sexual dimorphism
olfactory cues

Question 20

Sensory perception

Answer 20

Via Merkel cells and somatic sensory

Question 21

How does the skin support thermoregulation?

Answer 21

supports haircoat
regulates the cutaneous blood supply
sweat gland functions

Question 22

How does the body attempt to raise basal temperature?

Answer 22

piloerection (hair standing on end) for trapping air
vasoconstriction brings blood toward the core
shivering
breakdown of brown fat

Question 23

What is the critical temperature?

Answer 23

the external temp at which internal heating mechanisms cannot maintain a constant body temp

Question 24

Brown fat has an increased _______ and ______

Answer 24

blood supply; mitochondria

Question 25

How does the body attempt to lower basal temperature?

Answer 25

vasodilation (brings blood closer to the skin for radiational loss of heat)
evaporative cooling

Question 26

heat transfer from an animal to a cool surface is called

Answer 26

conduction

Question 27

heat transferred from the animal to the environment

Answer 27

radiation

Question 28

heat loss from the movement of air

Answer 28

convection

Question 29

heat loss that occurs when water becomes a gas

Answer 29

evaporation

Question 30

what environmental temperature rises respiratory rate in cats and dogs

Answer 30

cat: 90
dog: 81-84

Question 31

what is respiratory alkalosis?

a. the dangerous lowering of CO2 in the body
b. disruption in the blood-gas equilibrium
c. both a and b

Answer 31

c

Question 32

What animal produces watery saliva as an additional cooling mechanism

Answer 32

cats