Thermoregulation

Question 1

Core temperature varies with

Answer 1

Time of day
Stage of menstrual cycle
level of activity
age

Question 2

Regulatory mechanisms for maintaining body temp

Answer 2

Detectors in skin
hypothalamus
receptors in the core
-spinal cord
-viscera
-great veins

Question 3

Heat exhaustion

Answer 3

Failure of Cardio system
-decrease in circulating blood
-vasodilation of skin vessels
Dilated pupils and sweats profusely 
core temp normal or slightly elevated

Question 4

Heatstroke

Answer 4

Elevated core temperature
-loss of consciousness and convulsions
Cell/tissue damage

Question 5

2 forms of heatstroke

Answer 5

Classical- env. stress overwhelms an impaired thermoregulatory system- pt has preexisting condition

Exertional- Primary factor- high metabolic heat production
- pt usually young and fit

Question 6

Malignant hyperthermia

Answer 6

Massive increase in skeletal muscle in
-metabolic rate
-O2 consumption
-heat production
Majority of individuals have gene mutations
- ryanodine receptor- disrupt Ca homeostasis in skeletal muscle

Question 7

Hypothermia

Answer 7

core temp <95/35
common after immersion in cold water
Heat production cannot increase enough to compensate for heat loss

Question 8

frostbite

Answer 8

most vulnerable areas
-earlobes
-digits
Extensive ice crystals form in the cells of the skin and subQ areas
Gangrene can occur

Question 9

Radiation

Answer 9

Transfers heat as EM waves btwn objects
transfer rate depends on difference btwn two objects
mostly occurs during rest

Question 10

Conduction

Answer 10

Heat transfer btwn objects in contact

minimal exchange

Question 11

Convection

Answer 11

Loss or gain of heat by movement of air or water over body

Question 12

Evaporation

Answer 12

water fro skin and respiratory tract
-can carry larges amount of heat generated by body
occurs mostly during exercise

Question 13

Rate of heat production approx =

Answer 13

metabolic rate

Question 14

Rate of heat loss determined by

Answer 14

Rate of movement from core to skin
transfer from skin to env.
-most heat transferred from the core to the skin is by convection in the blood

Question 15

Skin as radiator system

Answer 15

Driven by SNS

• vasoconstriction when cold
• vasodilation when hot

Question 16

Free nerve endings in skin

Answer 16

Have many cold receptors to prevent hypothermia

Question 17

Aldosterone

Answer 17

allows the body to conserve NaCl in body instead of losing it while sweating

Question 18

Congenital anhidrosis

Answer 18

genetic inability to secrete sweat

-intolerant of warm env.

Question 19

Pyrogens

Answer 19

Body temperature is maintained higher when present

-take them away and the hypothalamus resets and body temperature returns to normal