Exam 39: Physiology, Homeostasis, and Temperature Regulation

Rainbow trout use acetylcholinesterase to break down the neurotransmitter acetylcholine.Researchers measured the rate at which this happened at 17°C and after the fish was acclimatized to 2°C.Their results showed that the rate was close to the same at both temperatures.Which is the most likely explanation for this result?

Suppose your car represents a physiological system.The desired speed of your car is

Ectotherms

Some birds, such as swifts, can lower their body temperature during periods of inactivity, which is an example of _______ hypothermia.

If you test the maximal tension a person can exert in her skeletal muscles at 35°C, it will be close to what she can exert at 25°C.But if she falls into icy water that is about 15°C, her ability to exert maximal tension in her skeletal muscles decreases sharply to about 30% of what she can exert at 25°C.From these data, you can conclude that the Q₁₀ value of exerting maximal tension in humans

Refer to the figure. If you were running very fast, which of these tissues would tire most quickly?

Refer to the graph. If the plot shows data collected from an experiment on a dog, at which environmental temperature does the dog expend energy to lose heat?

In an organ that secretes saliva, the tissue secreting the saliva is epithelial, and the tissue providing support for the organ is _______.

Which Q₁₀ value indicates that a reaction is not temperature sensitive?

Most biological Q₁₀ values are between _______ and _______.

The mechanism of heat production in brown fat depends on

A "hot" fish differs from a "cold" fish in having

Refer to the graph showing data collected from a mouse exposed to different ambient temperatures. What is the mouse's lower critical temperature?

Shivering

The temperature sensitivity of a physiological process or reaction is described in terms of its _______ value.

Which is an example of acclimatization?

Most physiological processes

Positive feedback

Refer to the figure showing the results of an experiment on a ground squirrel.Experimenters used a probe to directly heat or cool the squirrel's hypothalamus and measured the animal's metabolic rate and body temperature in response to this manipulation. A reasonable conclusion from these results is that the hypothalamus acts as a thermostat, controlling _______.

Refer to the figure. Which part of the figure shows the tissue most likely to be found lining ducts or tubules with a transport function?