Question

Which of the hormones are produced by the hypothalamus and stored in posterior pituitary?
(a) ADH and oxytocin
(b) FSH and LH
(c) TSH and STH
(d) ACTH and MSH

Answer 1

Hint: First hormone has function in the kidney for retention of water and vasopressor action and the second hormone is also known as uterotonics which plays a major role in the contraction of uterine muscles.

Complete step by step answer:
The two hormones secreted by the posterior pituitary are antidiuretic hormone (ADH) or vasopressin and oxytocin. The posterior pituitary gland hormones are synthesized by cell bodies within the hypothalamus. The posterior pituitary gland hormones aren't located within the pituitary gland itself but there are large neurons, called magnocellular neurons, located within the hypothalamus. The hormones are then transported within the axoplasm of the neuron nerve fibers which passes from the hypothalamus to the posterior pituitary gland gland.
ADH is made primarily within the supraoptic nuclei Oxytocin is made primarily within the paraventricular nuclei.
So, the correct answer is, ‘ADH and oxytocin.’

Additional information:
- In the absence of ADH, the luminal membranes of the tubular epithelial cells of the collecting ducts are almost impermeable to water.
- Inside the cell wall are an outsized number of special vesicles that have highly water permeable pores called aquaporins.
- When ADH acts on the cell, it first combines with membrane receptors which activate adenylyl cyclase and cause the formation of cAMP inside the tubular cell cytoplasm.
- Then, within the absence of ADH, the whole process reverses in another 5 to 10 minutes.
Oxytocin role of action:
- It may be a posterior pituitary gland gland hormone secreted by the posterior pituitary gland.
- Oxytocin acts through G protein- coupled receptors and therefore the phosphoinositide - calcium second- messenger system to contract uterine smooth muscle.
- Oxytocin also stimulates the discharge of prostaglandins and leukotrienes that augment contraction.
- Oxytocin in small doses increases both the frequency and therefore the force of uterine contractions.
- At higher doses, it produces sustained contraction.

Note:
- Hypothalamic control of the posterior pituitary glands.
- The posterior pituitary gland gland consists mainly of glial- like cells called pituicytes.
- The pituitary doesn't secrete hormones but they act simply as a structure for giant numbers of trigeminal nerve fibers and terminal nerve endings from nerve tracts that originate in the supraoptic and paraventricular nuclei of the hypothalamus.