When a hormone is present in high levels for a long time, the number of receptors on target-cells may decrease. This is called
A) sensory adaptation
B) paracrine regulation
C) up-regulation
D) down-regulation

Question

Quizplus · Accepted Answer

Down-regulation refers to the decrease in the number of receptors on target cells due to the presence of a hormone in high levels for a long period of time. This is a form of negative feedback to prevent overstimulation of the target cells.

When a Hormone Is Present in High Levels for a Long