Tag: role of hormones in reproduction

Estrogens are produced primarily by the ovaries. They are released by the Graafian follicles on the ovaries and are also secreted by the corpus luteum after the egg has been released from the follicle and from the placenta. 

Estrogen is the female sex hormone which is secreted by developing follicles in the ovary. Secretion of gonadotropins during the follicular phase of ovarian cycle stimulate growth and development of follicles. These developing follicles secrete estrogen. Thus, the correct answer is option C.

There are two major female sex hormones: estrogen and progesterone. Both of these are steroid hormones. In women, most estradiol is released from the ovaries and adrenal glands. It is also released by the placenta during pregnancy.

The primary function of oestrogen is the development of the female body and secondary sexual characteristics. These include breasts, endometrium, regulation of the menstrual cycle etc. They are present in significantly higher amounts in women after menarche (onset of menstrual periods at puberty) until menopause (cessation of menstrual periods after completion of reproductive age). Hence, oestrogen is a feminizing hormone.

Oestrogens, in females, are produced primarily by the ovaries, and during pregnancy, the placenta. Follicle-stimulating hormone (FSH) stimulates the ovarian production of oestrogens by the granulosa cells of the ovarian follicles and corpora lutea. Synthesis of oestrogens starts in theca interna cells in the ovary, by the synthesis of androstenedione from cholesterol. 

Ovaries produce and release two groups of sex hormones progesterone and estrogen. 

Relaxin, HCG and placental lactogen are protein hormones having amino acids bonded together in a polypeptide chain. Estradiol is a steroid hormone and has three cyclohexyl rings and one cyclopentyl ring joined into a single structure. Thus, the correct answer is D.

Oestrogen is a steroid hormone which is secreted by females gonads. Oestrogen is the hormone which is responsible for the development of secondary sexual characteristics in the female at puberty. It causes the development of breasts, axial and pubic hair and fat distribution. It is also responsible for the maintenance and maturation of the sexual organs in the human body. The hormone also plays role in thickening of the endometrium and other aspects of menstrual cycle and pregnancy.