Homeostasis and negative feedback：练习题

In mammals, which of the following best describes the principle of negative feedback in homeostasis?

Which of the following best explains why maintaining a stable blood pH is vital for homeostasis in mammals?

In mammals, homeostatic control of blood pH is critical for survival. Explain the biochemical consequence for metabolic pathways if the blood pH deviates significantly from the set point.

Thermoregulation in mammals involves the integration of multiple physiological systems. A researcher noted that extreme hypothermia can trigger a process where a decrease in core temperature leads to a reduction in metabolic rate, causing temperature to drop even further.

Identify the specific type of feedback represented by this self-reinforcing cycle and explain why the possession of separate mechanisms for cooling and warming is generally superior to a single mechanism for maintaining a stable body temperature.

Explain how the possession of separate mechanisms involving negative feedback provides a greater degree of control over the internal environment than a single mechanism.

(a) Define the term homeostasis and explain why it is essential for mammals to maintain a constant blood pH for metabolic efficiency. (2 marks)

(b) Describe the basic components of a negative feedback loop and explain how they work together to restore a physiological factor to its set point. (2 marks)

Mammals possess sophisticated systems to maintain their internal environment within narrow limits.

(a) Explain how the possession of separate mechanisms for cooling and warming the body provides a greater degree of control than a single mechanism. (2 marks)

(b) Describe the sequence of events in a negative feedback loop, beginning from the detection of a stimulus by a receptor to the response by an effector. (3 marks)