Flashcards in Animal Physiology-Environment Deck (39)
What happens to CNS activity during hibernation?
Must continue despite reduction in electrical and metabolic activit.It regulates maintenance of a set body temp, cardiac rhythm and respiratory. In addition, the animal should still be sensitive to external stimuli such as light, temp and touch
What happens to adipose tissue during hibernation?
Both WAT and BAT must remain responsive and retain function at the low Tb values of torpor
WAT is the dominant metabolic fuel throughout the hibernation
BAT is also responsible for the heat generation that maintains Tb when decreases in Ta
Does the black bear hibernate?
It does drop its temperature (not very much) however this is not true hibernation and is simply termed 'winter sleep'
Siberian hamsters save energy by exhibiting daily torpor, how does this save energy?
Reduces energy intake requirements and this means less time spent foraging which uses a lot of energy (the longer the bout, the bigger the energy saving) but remember that daily torpor does not cause rates to drop as low as hibernating animals
What is aestivation?
A state of torpor that is associated with lack of food and high environmental temperatures. Fish, reptiles, amphibians and some small mammals exhibit this. It allows survival of animals through long dry seasons (arid conditions): 9-10 months of a year
How can direct calorimetry measure energy use?
A method in which the animal is in a chamber surrounded by two chambers of water and the temperature of the water is measured. This gives an indication of the total heat loss which is proportional to the energy used
It can also be done with how much frozen ice is melted and collected
How can indirect respirometry measure energy use?
The animal is enclosed within the respirometer which contains soda lime - a CO2 absorbent and drying agent. The respirometer is sealed and a fixed volume of oxygen is introduced. Expired carbon dioxide and water are absorbed and thus the time taken for chamber pressure to return to its initial value indicates the rate of oxygen consumption by the animal (which indicates energy use)
How do you work out Heat production?
Heat production = C (body temperature (TB)) – ambient temperature (TA))