Question

Hypophyseal portal system is found in
A. Kidney
B. Liver
C. Brain
D. Heart

Answer 1

Hint: The hypophyseal portal system allows for the communication between the hypothalamus and the anterior pituitary gland structures for the hormonal signals. This system also plays an important role in many diseases involving the pituitary and central nervous system.

Step by step answer:The hypophyseal portal system helps to connect the brain to the anterior pituitary. This system is made up of two capillary beds, one is in the median and the other is in the anterior pituitary. The portal capillary bed in the median prominence is from the superior hypophyseal arteries and it is divided into two parts as an external and an internal plexus. The capillaries of the external plexus form the hexagonal, wire-like mesh embedded in the external surface of the median prominence. The interior of each hexagonal unit is filled with the axon terminals and with the glial tissue. It also includes tanycyte processes. The internal plexus consists of capillary loops that emerge from the external plexus and rise into the upper regions of the internal zone. The blood coming from the capillary system of the median is carried into a capillary bed in the anterior pituitary by the long portal veins. From the anterior pituitary capillary bed, the portal blood drains into the cavernous and the posterior intercavernous sinuses.
Therefore, the correct answer is option C.

Note:The hypophyseal portal circulation helps to provide the mechanism for the hypothalamic neuroendocrine regulation of the pituitary function and also it is responsible for the release of various pituitary hormones into the systemic circulation to maintain the homeostasis. The main hormones that are transported by this system include gonadotropin- the releasing hormone; corticotropin-the releasing hormone, growth hormone; Thyrotropin- the releasing hormone.