Mammalian Physiology

Question 1

Thermal Regulation

Answer 1

Types:

Poikilothermy: body temp varies with environment

Homeothermy: maintenance of constant temperature

Mechanism:

Ectothermy: use external sources to regulate heat (cold-blooded)

Endothermy: use internal sources (warm-blooded)

Question 2

Mammalian Thermoregulation

Answer 2

Mammals are endothermic homeotherms - mammals use up to 10x as much energy as equivalent-sized mammals

Mammals have fur/hair to provide insulation

Mammal body temperature is generally regulated at 37±1 °C but can vary (e.g hibernations, fevers)

Question 3

Mammalian Metabolism

Answer 3

Maintaining body temperature requires energy - cost is minimised when environmental temperature is closest to body temp (Tb)

Each species has a range of environmental temperatures at which it can maintain Tb at low cost - the Thermal Neutral Zone (TNZ) (can be fine-tuned by changing insulation)

when environment goes above or below TNZ the cost of maintaining Tb increases considerably

Question 4

Equation of Temperature

Answer 4