Question

concept check (module 3)

1. prolactin has a permissive effect on oxytocin in breast tissue. if prolactin levels were high, but oxytocin receptors had been blocked by a drug, what would be the result?

oxytocin would have a stronger effect on the target cells.
there would be no change from normal hormone action on the target cells.
oxytocin would have less of an effect on the target cells.

1. glucagon and insulin have antagonistic effects. glucagon signaling results in an increase in blood glucose concentration. what do you expect is the result of insulin signaling?

a decrease in blood glucose concentration
the secretion of insulin causes the secretion of glucagon
an increase in blood glucose concentration

Explanation:

Question 1

Prolactin has a permissive effect on oxytocin in breast tissue, meaning it helps oxytocin act effectively. If prolactin receptors are blocked, even with high prolactin levels, oxytocin's effect is reduced. So oxytocin would have less of an effect on target cells.

Insulin and glucagon are antagonistic. Glucagon increases blood glucose, so insulin (which lowers blood glucose) signaling should cause the opposite of glucagon's effect. So insulin signaling should lead to a decrease in blood glucose concentration.

Answer:

Oxytocin would have less of an effect on the target cells.

Question 2