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

Explain vanishing points., A vanishing point is where parallel lines that m...

A vanishing point is where parallel lines that move off into the distance seem to converge. It's an artifact of perspective. The vanishing point for any set of lines that are paral

Male reproductive disorders-cryptorchidism, Cryptorchidism Cryptorchid...

Cryptorchidism Cryptorchidism or incomplete descent of testis or retention of testis in the abdominal cavity occurs in all domestic species but is seen most commonly in stalli

Determine about the sense of contrast, Determine about the Sense of  Contr...

Determine about the Sense of  Contrast It is  the ability to  perceive  slight changes  in  luminance between  regions which  are not  separated by  definite borders. This  is

Genetics, Explain the difference between meiosos and mitosis

Explain the difference between meiosos and mitosis

Explain the history of nutrition, Explain the History of Nutrition? Kno...

Explain the History of Nutrition? Knowledge of human nutritional needs and relationship between diet and health was placed on a modern scientific footing only since the 19th ce

Explain the riboflavin content of rbc - riboflavin, Explain the Riboflavin ...

Explain the Riboflavin content of RBC - Riboflavin? The erythrocyte glutathione reductase assay, with an activity coe cient (AC) expressing the ratio of activities in the prese

Determine recommended nutrient intakes by selenium, Determine recommended n...

Determine recommended nutrient intakes by selenium? The FAO/WHO 2004 recommendation for nutrient intake for selenium by groups is given in Table. How do these recommendations c

Tingling or numbness in hands - symptoms of diabetes, Tingling or numbness...

Tingling or numbness is seen in cases of neuropathy. It occurs gradually over time. As high sugar (glucose) in the blood damages the nervous system, particularly in the extremities

What do you mean by the notochord, Q. What is the notochord? How is this st...

Q. What is the notochord? How is this structure formed? The notochord is a rodlike structure that outlines the supporting axis of the embryo and gives birth to the vertebral co

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