Pineal Gland (Epiphysis).pptx00000000000

The pineal gland

1. Pineal Gland (Epiphysis )

2. Pineal Glad-- Introduction a small cone-like structure It is a part of the  diencephalon . It is a neuroendocrine gland secretes the hormone melatonin Secretes several other polypeptide hormones that have a regulatory function on other  endocrine glands .

3. Pineal Gland classified as one of the secretory circumventricular organs of the brain, meaning that it has direct access to the bloodstream via fenestrated capillaries.

4. Pineal Gland projects posteriorly from the wall of the  third ventricle  above the  quadrigeminal plate , resting in the groove between the two superior colliculi. has several functions, the most important of which is maintaining the body’s circadian rhythm and regulating the sleep-wake cycle.

5. Pineal Gland plays a role in modulating the onset of puberty and the  development of the reproductive system .

6. Pineal Gland a part of the epithalamus , one of the three divisions of the diencephalon. develops as an outward projection from the posterior wall of the third ventricle, below the splenium of corpus callosum. It sits in the groove between the two superior colliculi, and is bilaterally related to the posterior aspects of the two thalami .

7. Pineal Gland The pineal gland is attached to the rest of the brain by the pineal stalk, The parenchyma mostly consists of cords and clusters of pinealocytes , and supporting astrocyte-like neuroglial cells.

8. Pineal Gland The pinealocytes are highly modified neurons that secrete the hormone melatonin into the surrounding network of fenestrated capillaries. The neuroglial cells are the main component of the pineal stalk.

9. Pineal Gland The parenchymal cells are the hormone-producing pinealocytes and the interstitial cells. In addition, perivascular phagocytes are present. The phagocytes share antigenic properties with microglial and antigen-presenting cells .