The hypothalamus is functionally anatomically connected to the poster, pituitary globe by bridge of
The correct answer and explanation is:
Correct Answer: The hypothalamus is functionally and anatomically connected to the posterior pituitary lobe by a bridge of nerve fibers.
The hypothalamus and the posterior pituitary gland (also known as the neurohypophysis) are connected through a specialized network of nerve fibers known as the hypothalamo-hypophyseal tract. This tract forms a direct neural connection, making the posterior pituitary an extension of the hypothalamus rather than a true gland.
Neurosecretory cells located in the hypothalamus produce two primary hormones: oxytocin and antidiuretic hormone (ADH), also called vasopressin. These hormones are not released immediately after production. Instead, they travel down the axons of the neurosecretory cells through the hypothalamo-hypophyseal tract. The hormones are stored in the axon terminals located in the posterior pituitary until a signal is received for their release into the bloodstream.
The connection between the hypothalamus and posterior pituitary is crucial for the body’s homeostasis. For example, ADH helps regulate the body’s water balance by increasing water reabsorption in the kidneys, while oxytocin plays a role in childbirth and lactation by stimulating uterine contractions and milk ejection, respectively.
Unlike the anterior pituitary, which is connected to the hypothalamus via the hypophyseal portal system (a network of blood vessels), the posterior pituitary does not synthesize hormones. It simply stores and secretes the hormones made in the hypothalamus.
This direct nerve-based connection ensures that hormone release from the posterior pituitary is tightly regulated by neural signals from the hypothalamus. This efficient communication system allows for rapid response to the body’s needs, such as maintaining water balance and responding to stress or reproduction-related signals.