In endocrine signaling,if the receptor molecule is removed from the target organ,then it will:

Receptors for protein hormones are located

In heart cells,which molecule acts as a second messenger and increases the contraction of muscle cells in response to adrenaline?

Receptors are made up of $.......$.

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: $FSH$,which interacts with membrane-bound receptors,does not enter the target cell.
Reason $(R)$: Binding of $FSH$ to its receptors generates a second messenger (cyclic $AMP$) for its biochemical and physiological responses.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which of the following glands secrete peptide hormones?