Question

Release of sex hormone is under the control of a hormone secreted by the
(a)Pituitary
(b)Hypothalamus
(c)Thyroid
(d)Both A and B

Answer 1

Hint: Sex Hormones are mainly gonadal steroids or gonadocorticoids that interact with the steroid hormone receptors and these are namely androgen, estrogen, and progesterone. These are made by the gonads or the adrenal glands or by conversion from other sex steroids in other tissues.

Complete answer:
Both Pituitary and Hypothalamus glands have a role in the release of sex hormones. It is controlled by the pulsatile release of a Hypothalamic hormone named GnRH or gonadotropin-releasing hormone. This GnRH further stimulates the release of LH and FSH (luteinizing hormone and follicle-stimulating hormone respectively) at the Pituitary gland. This LH binds with the target cells i.e. Leydig cells in the case of males and theca cells in females and results in the releasing of sex Hormone.

Additional Information: The released LH binds to the target cells and increases the production of steroidogenic acute regulatory protein or simply stAR which promotes the transfer of cholesterol to the inner mitochondrial membrane and this results in the initiation of steroidogenesis. By the action of P450scc, Cholesterol is converted to pregnenolone.
Pituitary gland- It is a pea-sized small gland located at the base of the brain between the eyes and attached to the hypothalamus. It is an important part of the endocrine system and secretes pituitary hormones namely Adrenocorticotropic hormone, Thyroid-stimulating hormone, Growth hormone, prolactin, and two gonadotropins- LH and FSH.
Hypothalamus- It is located at the base of the brain as well and connects the endocrine system to the nervous system. It has the main role in controlling body temperature, hunger, thirst, and circadian cycle. It releases hormones like oxytocin, vasopressin, etc.
Therefore, the correct answer is “both A and B”.

Note: Sex hormones are mainly steroids that interact with vertebrate steroid hormone receptors. The pituitary and Hypothalamus have great roles in the secretion of these hormones. However, the thyroid gland has no role in this. It is the largest gland found in the human body and is present in the throat. This controls the rate by which the body burns energy, makes proteins, and also the sensitivity of the body to other hormones. The hormones made by the thyroid gland are thyroxine (T4) and triiodothyronine(T3). It also produces calcitonin that plays a role in calcium homeostasis.