Pineal gland, Biology

Assignment Help:

PINEAL GLAND (EPIPHYSIS CEREBRI) -

  • It develops from the ectoderm of the embryo.
  • The pineal gland is located between the cerebral hemispheres, where it protrudes from the roof of the third ventricle.
  • The pineal gland is a small rounded body which consists of pineal cells and supporting glial cells.

Hormone - Melatonin concentration in the blood appears to flow a diurnal (day-night) cycle as it arises, in the evening and through the night and drops to a low around noon. Because of this light mediated response, the pineal gland may act as a kind of "biological clock" which may produce circadian rhythms (variations following a 24 hour cycle).

  • Melatonin lightens skin colour in certain animals and regulates working of gonads (testes and ovaries).
  • Light falling on the retina of the eye decreases melatonin production, darkness stimulates melatonin synthesis.

                      Girls blind from birth attain puberty earlier than normal, apparently because there is no                             inhibitory effect of melatonin on ovarian function.

  • Serotonin, a neurotransmitter found in other locations in the brain, is also found in the pineal gland. Research evidence is accumulating to support the idea that the pineal gland may be involved in regulating cyclic phenomena in the body.
  • In man the pineal gland starts to calcify at about the time of puberty. Such calcium deposits are called the brain sand.

Related Discussions:- Pineal gland

What would most likely be true, You are given a metaphase chromosome prepar...

You are given a metaphase chromosome preparation (a slide) from an unknown organism that contains 12 chromosomes. Two that are clearly smaller than the rest appear identical in len

Explain about the color vision of human eye, Explain about the Color vision...

Explain about the Color vision of human eye The human eye can see about 150 different colours in the visible spectrum (400- 750 nm). Red, green and blue are said to be the prim

Kingdom animalia, in what order did the shellfish belong? in what genus did...

in what order did the shellfish belong? in what genus did the shellfish belong? in what species did the shellfish belong?

Describe two differences among green algae and plants, Describe two differe...

Describe two differences among green algae and plants. Algae lack tissue differentiation and have no true roots, leaves and stems. The gametangia of algae are single-celled; th

Enzyme activity, Enzyme Activity Enzymes are biomolecules which catalyz...

Enzyme Activity Enzymes are biomolecules which catalyze (i.e. increase the rates of) chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules

Needle and sharp instrument safety, Needlestick/sharp instrument injuries a...

Needlestick/sharp instrument injuries are of major concern to health care workers. All of the significant exposures reported in the academic year 2003/04 in our Faculty, were injur

What are organogenesis and histogenesis, Q. What are organogenesis and hist...

Q. What are organogenesis and histogenesis? Histogenesis is the procedure of tissue formation in the embryonic development. Organogenesis is the procedure of organ formation. B

What is the difference between venous and arterial blood, Q. What is the di...

Q. What is the difference between venous and arterial blood? Arterial blood is the oxygen-rich and carbon dioxide-poor blood that irrigates the tissues. Venous blood is the oxy

Define changes in food due to concentration process, Define Changes in Food...

Define Changes in Food due to Concentration Process? Obviously concentration that exposes food to 100°C or higher temperatures for prolonged periods can cause major changes in

Explain the direct microscopic counts (dmc), Explain the Direct Microscopic...

Explain the Direct Microscopic Counts (DMC) The process includes making a smear of food sample on a microscope slide followed by staining with an appropriate dye and viewing an

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd