Question

3.1.9 - 12c
the liver acts to keep blood glucose at a relatively constant level. it takes up glucose from the blood when levels are too high, and adds glucose to the blood when levels are too low.
are these actions of the liver an example of homeostasis?
yes, because homeostasis involves the maintenance of constant internal conditions.
no, because homeostasis involves only positive feedback, not feedback inhibition.
no, because homeostasis involves only tissues and organs from the same organ system.

Explanation:

Homeostasis is the maintenance of a stable internal environment. The liver's regulation of blood glucose levels (taking up glucose when high and adding when low) is a classic example of maintaining a constant internal condition (blood glucose level). Positive feedback is not the only mechanism in homeostasis (negative feedback like here is also common). Also, homeostasis can involve different organ systems.

Answer:

Yes, because homeostasis involves the maintenance of constant internal conditions.