Question

GnRH, a hypothalamic hormone, needed in reproduction, acts on.
A. Posterior pituitary gland and stimulates secretion of LH and relaxin
B. Anterior pituitary gland and stimulates secretion of LH and oxytocin
C. Anterior pituitary gland and stimulates secretion of LH and FSH
D. Posterior pituitary gland and stimulates secretion of Oxycontin and FSH

Answer 1

GnRH is known as a gonadotropin hormone which is usually released by the hypothalamus. GnRH secretion usually differs in men and the women. In women, the pulse frequency often fluctuates in the cycle of menses wherein a huge surge of the GnRH is then observed before ovulation. In males however, this hormone is usually produced in pulses with a consistent/stable or normal frequency.

Complete answer:
Gonadotropin releasing hormone normally regulates the secretion of the LH(or luteinizing hormone) and FSH(or follicle stimulating hormone) from the anterior pituitary. The GnRH is then produced by hypothalamus and is normally supplied through the bloodstream into the pituitary gland. Parts of the brain then sends out the neural inputs which often control the secretion of GnRH. In females, the secretion in particular, is normally controlled by the sex steriods through the negative feedback. In addition, the hormone then causes the release of the progesterone and estrogen in the ovaries. In males, GnRH often causes the testicles to produce testosterone..

GnRH then triggers the production & secretion of the FSH and LH at the pituitary gland. They are then regulated by a he metrics, in size, the frequency of the GnRH pulses in addition to the feedback which is received from the strogens and the androgens. FSH is often released with a favourable condition of the GnRH pulses which are at quite a low frequency while the LH pulse production is often triggered by GnRH pulses which are at a higher frequency parallely in comparison to former.

Hence, the correct answer is option (C).

Additional information:
Damage to the hypothalamus can also then lead to a lack in the GnRH secretion which can halt the normal production of LH and the FSH. In women, this often results in loss of the menstrual cycles, in men which leads to loss of sperm production and overall, loss of the hormones in ovaries and the testes.

Note: GnRH is then secreted from the hypothalamic cells. These hormones are then let into the bloodstream into the blood vessels which then carry the hormone to the pituitary gland. In the response, the pituitary gland then releases the FSH and LH which is usually critical for the normal health of male & the female reproductive systems.