Question

permissive action of hormones is best described as what?
the synergistic action of two hormones on a target organ.
a hormone counteracting the effects of another hormone.
a hormone enhancing the responsiveness of a target organ to another hormone.
a hormone directly causing a physiological response in the absence of other hormones.
a hormone inhibiting the action of another hormone.

Explanation:

• Option 1: Synergistic action means two hormones working together to have a combined effect (e.g., both increasing a response). This is not permissive action.
• Option 2: A hormone counteracting another is an antagonistic effect (e.g., one hormone lowering blood sugar and another raising it). Not permissive.
• Option 3: Permissive action is when one hormone enhances the responsiveness of a target organ to another hormone. For example, estrogen (a hormone) priming the uterus so that progesterone (another hormone) can have a more effective action on it.
• Option 4: This describes a hormone acting alone, not in relation to another hormone's action (which is what permissive action is about - a relationship between hormones).
• Option 5: Inhibiting another hormone's action is different from permissive action. Permissive is about enhancing responsiveness, not inhibiting.

Answer:

A hormone enhancing the responsiveness of a target organ to another hormone.