Physiology: fever & ways of heat loss

Question 1

briefly describe what radiation is, in terms of heat loss

Answer 1

emission of heat energy in the form of electromagnetic waves from the body surface

Question 2

briefly describe what convection is, in terms of heat loss

Answer 2

transfer of heat by air/water currents that help carry heat away from the body(e.g. wind)

Question 3

briefly describe what conduction is, in terms of heat loss

Answer 3

transfer of heat objects in contact( heat moves from warmer to cooler objects)

Question 4

briefly describe what evaporation is, in terms of heat loss

Answer 4

expenditure of energy to convert water on skin surface/lining of airways into vapour

Question 5

give an example of active evaporative heat loss and what controls it

Answer 5

sweating, controlled by the sympathetic nervous system

Question 6

what affects the extent of evaporation

Answer 6

relative humidity of the atmosphere

Question 7

what is a pyrogen

Answer 7

something that induces fever

Question 8

what do pyrogens stimulate the release of

Answer 8

prostoglandins

Question 9

describe the action of prostoglandins

Answer 9

change temp. set point of the hypothalamus to a higher temp.

Question 10

how does the body respond to action of prostoglandins

Answer 10

initiates cold response mechanisms(e.g. shivering) to increase the body temp. to the new set point
this is a fever

Question 11

how does the body/anti-pyretics fight fever

Answer 11

induce hot response mechanisms(e.g. sweating) to reduce body temp.

Question 12

what body temp. defines hypothermia

Answer 12

<35 degrees

Question 13

what body temp. defines hyperthermia

Answer 13

> 40 degrees