Regulation Of Temperature

Question 1

Which part of the brain is responsible for temperature regulation?

Answer 1

Hypothalamus

Question 2

What is normal body temperature?

Answer 2

37 degrees celcius

Question 3

What is the maximum temperature that someone can survive?

Answer 3

43 degrees celcius

Question 4

Where can core temperature be taken from?

Answer 4

Ear canal
Oral cavity
Axilla
Rectum

Question 5

Which organs produce the most heat through metabolism?

Answer 5

Brain
Skeletal muscles
Visceral organs

Question 6

The most exposed areas of skin in the fingers, toes, ears and nose there are additional blood vessels. What are these called and what is their function?

Answer 6

Arteriovenous anastomoses. They are shunt vessels and can open and close in order to allow less/more blood to the extremities according to thermoregulatory requirements

Question 7

Explain the countercurrent arrangement of deep arteries and veins in relation to thermoregulation.

Answer 7

Deep arteries and veins are in close proximity, so in cold environments arteries will be at or near core temperature and blood temperature will cool as blood travels away from the core. Heat can be transferred from the arteries to the returning veins to progressively warm blood in the veins to core temperature.

Question 8

How can heat be lost from the body?

Answer 8

Conduction
Convection
Radiation
Sweat

Question 9

What are the behavioural responses as a result of a decrease in temperature?

Answer 9

Seeking warmer environment
Putting on warmer clothes
Turning heating up
Eating and drinking warm fluids

Question 10

What are the physiological responses to a decrease in temperature?

Answer 10

Vasoconstriction
Shivering
Non-shivering thermogenesis

Question 11

Vasoconstriction results from an increase in sympathetic activity. T/F?

Answer 11

True

Question 12

Describe the shivering process.

Answer 12

ATP is hydrolysed by muscle contraction which produces heat energy.
Muscles perform no external work so virtually all energy is converted to heat energy

Question 13

Is shivering involuntary or voluntary?

Answer 13

Mostly involuntary

Question 14

What is non-shivering thermogenesis?

Answer 14

The production of heat through processes other than muscle contraction such as brown fat metabolism

Question 15

Describe brown fat metabolism in relation to thermoregulation.

Answer 15

Cold environments result in an increase in catecholamine secretions which activate hormone-sensitive lipase in brown fat cells. The resulting glycerol and free fatty acids can be used for heat production. Tri-iodothyronine also causes the synthesis of uncoupling protein one which uncouples the electron transport chain from ATP synthesis to produce heat rather than storing energy as ATP

Question 16

What are the behavioural responses to an increase in temperature?

Answer 16

Shedding of clothing
Reduction of activity
Drinking cold fluids
Seeking cooler environment

Question 17

What are the physiological responses to an increase in temperature?

Answer 17

Vasodilation

Sweating

Question 18

Evaporation of sweat is most efficient in humid conditions. T/F?

Answer 18

False - humid conditions make sweat evaporation less efficient

Question 19

ADH and aldosterone are secreted when sweating is increased. Why?

Answer 19

When sweating increases sodium and chloride reabsorption from sweat becomes less efficient. ADH and aldosterone promote electrolyte reabsorption in the kidneys to prevent against electrolyte imbalance