MCM Final - Skin Physiology

Question 0

glomus bodies

Answer 0

function to direct blood way from skin surface when exposed to cole temperature

- way to prevent heat loss
- also allows for max heat disappation

Question 1

apical skin

Answer 1

present on nose, lips, ears, hands, feet (more distal)

high surface are to volume ratio
-favors heat loss

has glomus bodies

under SNS control (tone high under normal conditions)

Question 2

non-apical skin

Answer 2

lacks glomus bodies

cholinergic - vasodilation
adrenergic - vasoconstriction

Question 3

kallinrein and bradykinin

Answer 3

vasoactive compounds relax vascular smooth muscle

Question 4

cutaneous blood supply

Answer 4

blood to dermis only (epidermis is avascular)

increased core temp - passive vasodilation - heath loss

decreased core temp - increase SNS tone vasoconstriction - conserve heat

Question 5

white reaction

Answer 5

blanching of skin when stroked with sharp instrument

expulsion of blood bc of microvascular smooth muscle contraction
-empties capillary loop

lasts 15-60 seconds

Question 6

triple response

Answer 6

with more forceful pointed instrument

red reaction > flare reaction > wheal reaction

Question 7

red reaction

Answer 7

increased redness due to vasodilator release from disturbed cells

Question 8

flare reaction

Answer 8

red line from red reaction spreads out after several seconds

dilation of arterioles from axon reflex (local neural response to sensory receptor stimuli)

Question 9

wheal reaction

Answer 9

line of injury with local edema

due to increased permeability in response to HISTAMINE

Question 10

apocrine sweat glands

Answer 10

empty into hair follicles

active at puberty

produce BO

no role in body temp reg

Question 11

merocrine sweat glands

Answer 11

aka eccrine

main role is body temp regulation

acetylcholine triggers sweat secretion
Na/K/Cl cotransporter mediates excretion of NaCl, urea, lactate > water follows

Na and Cl are reabsorbed resulting in HYPOTONIC SWEAT

Question 12

CFTR

Answer 12

cystic fibrosis transmembrane receptor

defects lead to inability to reabsorb Na and Cl of salt
excess loss of these ions
-bummer dude!

Question 13

intrinsic aging

Answer 13

independent of sun exposure

decreased epidermal thickness
decreased melanocytes
decreased immune surveillence
ECM decays

Question 14

photoaging

Answer 14

due to sun exposure

causes coarse wrinkles

Question 15

shivering

Answer 15

temp regulation in cold

-can increase heat production by 400% wowza!

Question 16

passive heat loss

Answer 16

radiation, convection, evaporation

Question 17

conduction

Answer 17

heat transfer between skin and solid environmental objects

Question 18

radiation

Answer 18

heat loss to air

Question 19

convection

Answer 19

wind carries heat away from body

Question 20

peripheral sensory receptors for heat

Answer 20

all over skin surface
both warm and cold sensors

pathway from CNT via thalamic pathway to cerebral cortex

Question 21

central receptors for heat sensation

Answer 21

near preoptic and anterior hypothalamus

sense internal (core) temperature

important in regulating during exercise

Question 22

efferent signals from the CNS in heat regulation

Answer 22

blood flow from core to skin surface

SNS adjusts skin blood blow

sweat glands (eccrine) activated by SNS (more evap cooling)

skeletal muscles shiver - involuntary contractions/relaxations
-increase body temp

Question 23

SNS effect on blood flow to skin

Answer 23

stronger affect on sweating (not so much on blood flow to skin)

Question 24

kinins

Answer 24

cause dilation of arterioles, constriction venules

increased capillary pressure and permeability

Question 25

cytokines and thermoregulation

Answer 25

released by macrophages and lymphocytes in response to infection and inflammation

release prostaglandins that interact with 3rd ventricle of brain

sweating inhibited and shivering occurs
-increase temp to enhance immune response

Question 26

mechanoreceptors in skin

Answer 26

pacinian, meissners, ruffinis, merkels, krauses