L4 - Thermoregulation

Question 1

Core Temperature

Answer 1

Approx 37

Question 2

Shell Temperature

Answer 2

1-6 lower than core

Question 3

How much heat produced per day?

Answer 3

6300kJ
Measured by O2 consumption
Varies based on environment, activity, hormones, age, gender, muscle mass and sleep

Question 4

Sources of heat production

Answer 4

Basal Metabolic rate 60%
Muscle contraction 30%
Food digestion 10%
Thermogenesis
Shivering
Radiation (sun)
Conduction (hot surfaces)

Question 5

Heat loss

Answer 5

Radiation 60%
Evaporation 25%
Convection 12%
Conduction 2%
Faeces and urine 1%

Question 6

Transfer of heat in body

Answer 6

Heat generated in body core
- Liver, brain, heart
Transferred through rest of body
- Conducton via tissue
- Convection via blood (larger effect)

Question 7

Thermoregulation when core temp decreases

Answer 7

1. Central thermoreceptors detect drop in temp
2. Control centre (hypothalamus) sends neural signal
3. Effectors recieve signal and increase metabolism (fats), activate muscles (shivering) and cutaneous blood vessel constriction (conserve heat)

Question 8

Thermoregulation when core temp increases

Answer 8

1. Peripheral thermoreceptors detect increase in temp
2. Control centre sends signal
3. Effectors stimulate sweat glands and vasodilation