Pineal gland

Pineal gland/ pineal body

Pineal gland is small body attached to roof of the third ventricle of brain in midline, beneath the posterior end of corpus collosum.

It is located in epithalamus (part of diencephalon).

Size 

Pineal gland is about 8-10mm long and 5mm wide and mass 0.1-0.2gm, is radish brown in color and surrounded by capsule formed by pia meter.

Pineal gland consist of masses of neuroglia and secretory cells called pinealocytes. 

Pineal gland landmark for determining brain orientation in X-rays.

Pineal Gland Hormone

Melatonin is main hormone secreted by pineal gland.

Secretion is controlled by daylight and level fluctuate during each 24-hour period, being highest at night and  lowest around mid day.

Melatonin concentration in blood rise and fall in daily cycle. Peak level occurs during night, lowest level occurs around him.

Melatonin is to be association with;

1. Contribute to setting body's biological clock.

2. Melatonin controls pigmentation changes by aggregation of melanin.

3. Melatonin production is influence by detection of light and dark by retina of eye.