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

How are the male gametophytes formed in angiosperms, Q. How are the male ga...

Q. How are the male gametes and the male gametophytes formed in angiosperms? In the anthers of every stamen there are pollen sacs. Inside the pollen sacs there are microspore m

Show the communication process steps, Q. Show the Communication process ste...

Q. Show the Communication process steps? Planning - Set goals. - Make a plan with alternatives. - Allow the counsellee to select a alternative which is feasible.

Determine the meaning of response cost, Determine the meaning of Response c...

Determine the meaning of Response cost This is a type of punishment in which the subject has to return back the token (positive reinforcement) earned earlier if the subject dis

Bovine spongiform encephalopathy (bse), Normal 0 false fal...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Explain the biography of pedanius dioscorides, Explain the Biography of Ped...

Explain the Biography of Pedanius Dioscorides? Pedanius Dioscorides, a Cicilian Greek, who lived in the first century A.D. was the most important botanist after Theophrastus. H

Differences between prokaryotes and eukaryotes, Differences between Prokary...

Differences between Prokaryotes and Eukaryotes It is obvious that there are a number of differences between them. Prokaryotes, like bacterial cells are generally much smaller,

Define about the pancreatic cancer, Define about the Pancreatic Cancer? ...

Define about the Pancreatic Cancer? This is a condition often associated with abdominal pain, anorexia, nausea, and vomiting and weight loss. Ealing may aggravate pain. There m

Give examples of diseases caused by bacteria, Give three examples of diseas...

Give three examples of diseases caused by bacteria, Diseases caused by bacteria contain tonsillitis, blood poisoning, scarlet fever, tuberculosis, typhoid, diphtheria, food poi

Cell biology, explain in detail the cell theory and it exceptions

explain in detail the cell theory and it exceptions

Renal parenchymal disease, Renal parenchymal disease is the commonest cause...

Renal parenchymal disease is the commonest cause of secondary hypertension.  Hypertensive and diabetic nephropathy and chronic glomerulonephritis are the main causes. Eventually, t

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