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

Describe circulatory system, Circulatory system:  One of the eleven major b...

Circulatory system:  One of the eleven major body organ systems in animals; carbon dioxide, nutrients, transports oxygen, and waste products between the cells and the respiratory s

What are gametes, Q. What are gametes? Gametes are cells specialized in...

Q. What are gametes? Gametes are cells specialized in sexual reproduction and they contain half of the maximum number of chromosomes of the species and unite it with another ga

What is lipoproteins, A lipoprotein is a biochemical assembly which haves b...

A lipoprotein is a biochemical assembly which haves both lipids and proteins, bound to the proteins that allow fats to move by the water outside and inside cells. The proteins serv

Medical records, Medical Records This includes: health history o...

Medical Records This includes: health history of patient/client  a report of the findings on examination  signs and symptoms  observation records  progress

How does aldosterone act and where is it produced, How does aldosterone act...

How does aldosterone act and where is it produced? Aldosterone is a hormone that acts upon the nephron tubules stimulating the resorption of sodium. Thus it contributes to the

Explain systematic - modern trends in animal taxonomy, Explain Systematic -...

Explain Systematic - Modern Trends in Animal Taxonomy Systematic is defined as the study of relationship among organisms which means reconstruction of phylogenies. It is that b

Xerarch - ecology, Xerarch - Ecology Successions initiated on bare roc...

Xerarch - Ecology Successions initiated on bare rock, wind-blown sand, rocky talus slopes, or other situations where there is an extreme deficiency of water are termed xerarch

Signs and symptoms and treatments of hepatitis c, Q. What are the modes of ...

Q. What are the modes of transmission, main signs and symptoms and treatments of hepatitis C? The Hepatitis C is caused by the RNA virus and transmitted through blood (like hep

Explain phylum cnidaria - coelenterates, Explain Phylum Cnidaria - Coelente...

Explain Phylum Cnidaria - Coelenterates? Members of the Phylum Cnidaria and one other group-Phylum Ctenophora (the comb jellies)-are the only two animal phyla that have radiall

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