Melatonin is secreted by the Pineal body, also known as the pineal gland. Melatonin is a hormone that plays a crucial role in regulating the sleep-wake cycle and circadian rhythms. It is produced in response to darkness and helps signal the body that it is time to sleep.
So, the correct option is (A): Pineal body
A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is :
The current passing through the battery in the given circuit, is:
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :
The chemical coordination and integration of all physiological functions in the animal body are jointly synchronized by the neural and endocrine systems. The control and coordination of body functions are executed by the endocrine glands. They are ductless glands that secrete severel hormones to control and coordinate body functions.
The human body has several endocrine glands located in different parts. They cover the pituitary gland, thymus, thyroid gland, pineal gland, parathyroid, pancreas (dual gland), adrenal gland, and gonads (testes and ovaries). The liver, kidney, heart, and gastrointestinal tract also produce hormones in small traces to harmonize the functioning of these organs.
The Hypothalamus comprises groups of secretory cells called nuclei which secrets various hormones. These hormones released by the hypothalamus are important in regulating the synthesis and secretion of pituitary hormones.