Question

Select the correct statement regarding the hypothalamic hormones.

• A. Growth hormone secretion is regulated by GHRH
• B. Blood flows from the anterior pituitary to the hypothalamus in portal vessels.
• C. Hypothalamic releasing hormones are synthesized and secreted by neuron
• D. The hypothalamic releasing hormones reach through general circulation.

Answer 1

The correct option is C

Hypothalamic releasing hormones are synthesized and secreted by neuron

The hypothalamus is made up of several neurosecretory cells arranged in the form of nuclei which produce different hormones. The hormones produced by hypothalamus are of two types, the releasing hormones (which stimulate secretion of pituitary hormones) and the inhibiting hormones (which inhibit secretions of pituitary hormones). For example, a hypothalamic hormone called gonadotropin-releasing hormone (GnRH) stimulates the pituitary synthesis and release of gonadotropins. On the other hand, somatostatin from the hypothalamus inhibits the release of growth hormone from the pituitary. These hormones originating in the
hypothalamic neurons, pass through axons and are released from their nerve endings. These hormones reach the pituitary gland through a portal circulatory system and regulate the functions of the anterior pituitary. The posterior pituitary is under the direct neural regulation of the hypothalamus.