Thermoregulation - Topic 1 Flashcards
What is an ectotherm?
Enctotherms have body temperature that changes with the temperature of the environment
What is an endotherm?
Endotherms generate metabolic heat to maintain internal temperature
Periphery of the body and core temperature?
The periphery of the body can withstand some deviation from core temperature
What is conduction?
direct contact
What is convection?
heat moves from core to body surface
What is radiation?
Warm objects loose heat through radiation
What is evaporation?
sweat evaporates and cools the body
How is temperature change detected in endotherms?
In endotherms temperature sensitive cells in the hypothalamus detect temperature changes and trigger homeostatic responses
Temperature receptors are also found in the skin
How is temperature regulated?
Structural features
Behavioral responses
Physiological mechanisms
What are structure for heat regulation?
- Special body covering and blubber
- Vascular body parts for heat exchanges
- Brown adipose (fat) tissue
- Increased number of mitochondria
What are behavioral responses?
Kleptothermy - huddling together
Torpor - metabolic rate
Improve evaporate cooling - licking limbs, spraying water in body, wallowing in mud or water
What are physical mechanism to generate heat?
Vasoconstriction
Shivering
Piloerection
TRH
What is vasoconstriction?
is the constriction of the blood vessels in the skin which prevents heat loss
What is shivering?
Involuntary movement of muscles generates large amounts of heat, stimulated by adrenaline
What is piloerection?
Goosebumps: caused by the contraction of muscles at base of hair follicle and causes hairs on skin to stand up. It traps warm air close to the skin
