Breaking out in a sweat T7 Flashcards
1
Q
Explain how body temperature is maintained during a period of intense exercise, with reference to each stage within the homeostatic control mechanism.
(5)
A
- Temp increases above normal level.
- This is detected by thermo-receptors in skin/the hypothalamus.
- Impulses pass to hypothalamus.
- Heat loss centre activated.
- Impulses sent to sweat glands.
- Evaporation of sweat causes a cooling effect.
- Impulses sent to shunt vessels in the skin.
- Shunt vessels constrict / vasodilation.
- More blood flow through skin surface capillaries.
- More heat loss via radiation.
- Body temp. falls back to normal, via negative feedback.
2
Q
What is meant by the term homeostasis.
1
A
Maintenance of a constant internal environment.
3
Q
Define negative feedback.
1
A
When an increase/decrease in the norm triggers mechanisms to return the body back to normal.
4
Q
Why is it important that core temperature remains stable?
A
- Allows a stable rate of enzyme controlled reactions.
- Temp. too low, there is an insufficient concentration of kinetic energy, enzyme and substrates less likely to move and form substrate-complex.
- Temp too high, enzymes denature.