Question

Melanocyte stimulating hormone (MSH) is secreted by ___________ of the pituitary
A. Anterior lobe
B. Median lobe
C. Posterior lobe
D. Not any particular lobe

Answer 1

Melanocyte stimulating hormone (MSH) is also called intermedin. This is named after the pituitary lobe from which it is secreted. The pituitary gland consists of two parts-Adenohypophysis and Neurohypophysis. Adenohypophysis is formed of two lobes-anterior lobe and median lobe while neurohypophysis forms of the posterior lobe. The three lobes of the pituitary are given in the options to choose from.

Complete answer:
MSH is called intermedin or melanotropin. They are released by the median lobe of the pituitary into the bloodstream. The melanotropin then circulates in the blood until it comes in contact with melanocortin receptors (MCR). These receptors are present primarily on melanocytes (pigment-containing cells). The binding of MSH to MCR ensures higher pigmentation and subsequent darkening of the skin. MSH is also shown to have to suppress appetite in mammals.
MSH secretion is inhibited by corticosteroids from the adrenal cortex.

Let’s check on the other two lobes and see their characteristics.
Anterior lobe – It is also called adenohypophysis. This part of the pituitary has at least five different types of hormone-producing cells. The hormones secreted from this region include Adreno cortico tropic hormone (ACTH), Follicular stimulating hormone (FSH), Luteinizing hormone (LH), Growth hormone (GH, somatotropin), and prolactin (PRL)
Posterior lobe – The posterior pituitary is called neurohypophysis. It is considered an extension of the hypothalamus from the brain. So the posterior lobe in itself doesn’t have any hormone-producing cells. They usually store hypothalamus secreted hormones and adequately secrete them to the bloodstream. The hormones stored here are oxytocin and vasopressin.

Melanocyte stimulating hormone (MSH) is secreted by the median lobe of the pituitary.

Note:
If we just know about anterior and posterior pituitary lobes, it can be confusing to place MSH in any of these options. Especially with an option saying not any particular lobe. So be sure of the fact that only anterior and median lobes produce hormones on their own. And the median lobe only produces MSH (intermedin).