Hibernation and topor. Flashcards
What is torpor ?
Topor is the process where an animals body temperature will drop over night for a few days (never below 15 degrees celcius) and become physically inactive to save enrgy in cold environments- also known as adaptive hypothermia.
In which animals is hibernation most common ?
Small mammals at high latitudes and altitudes where cold weather is sustained for a long period of time.
How much does the body temp of a hibernating animal drop during hibernation ?
Will drop close to the ambient temperature but will never drop below 0 degrees as this would be lethal.
Name 3 problems associated with hibernation.
- Poor muscle and nervous coordination
- Slow circulation causes the risk of thrombosis
- Drop in kidney activity causes the build up of toxic waste.
How are animals prepared for hibernation?
The euthermal season is organised that hibernation is possible during cold wether. Reproductoin is timed when the food is abundant so that young are big enough to enter hibernation. Fat stores increase rapidly in the late summer.
Once entering hibernation what happens to the body of the organism ?
Wide fluctuations in heart rat and oxygen consumption.
What happens to the heart rate and cardiac output during hibernation ?
- Heart rate drops to 3-10 bpm
- Cardiac output becomes 1.5 % of the normal
What is periodic arousal ?
Where animals in hibernation wake up sporadically through the cold season
Why period arousal ?
Alarm response to temp or vibration. To eat. Remove toxic waste. Restore blood sugar levels.
Which parts of the body is blood directed to first during arousal ?
Forelimbs, Heart, Diaphragm and thorax.
What changes are made to blood flow in periodic arousal ?
Heart rate is increased and vasodiltion occurs
What is a temperature set point in the hypothalamus ?
if a threshold temperature is reached the hypothalamus causes the metabolic rat to increase to increase body temp.
How much energy does hibernation save compare dto if the animal styed euthermic during this period ?
87.8 %
What happens to the blood and endocrine glands during hibernation?
- Acidosis (decrease in pH)
- Increase in the bloods affinity for oxygen
- Atrophy of the endocrine glands occurs
