Question

In females, hormone inhibin is secreted by
a. Granulosa cells and corpus luteum
b. Granulosa and theca cells
c. Granulosa and cumulus oophorus cells
d. Granulosa cells and zona pellucida

Answer 1

Hint: In humans, Inhibin inhibits FSH production. Females produce this Inhibin in the gonads, pituitary gland, placenta, corpus luteum, granulosa cells and other organs while males secrete it from the Sertoli cells, located inside the testes.

Complete answer:
Inhibin is a multifunctional hormone that regulates pituitary FSH secretion. Inhibin is gonadal messengers involved in negative feedback control on FSH released from the pituitary gland. Inhibin is paracrine ovarian and testicular regulators. Its paracrine effects in the uteroplacental unit are currently used in the diagnosis of male and female infertility, gynaecological and gestational diseases.
Inhibin is glycoproteins produced by the granulosa and theca cells of the ovary and by the Sertoli cells of the testis. There are two active molecular forms of Inhibin:
Inhibin A
Inhibin B
Inhibin A and Inhibin B are heterodimers made by an α subunit and either βA (inhibin A) or βB (inhibin B) subunits.
Hence, the correct answer is (A) In females, hormone inhibin is secreted by Granulosa cells and corpus luteum

Note:We can conclude that:
Inhibin A and inhibin B are synthesised at different times in human males and females and from several different cell types. Both suppress FSH production and show local paracrine effects in the gonads.
Ovary and testis are the main inhibin A- and inhibin B-producing organs since puberty.
Inhibin A is secreted mainly by the corpus luteum and is involved in the negative feedback control of FSH secretion during the luteal–follicular transition.
Inhibin B is secreted by antral follicles in response to FSH. Thus, inhibin B level is a marker of ovarian function.
Inhibin B is a marker of spermatogenesis. Its secretion decreases with age.
During pregnancy, the placenta predominantly secretes Inhibin A also produced by the corpus luteum.