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

Heteroduplex dna, Heteroduplex Dna  is generated by the base pairing betwee...

Heteroduplex Dna  is generated by the base pairing between complementary single strands derived from the different parental duplex molecules; heteroduplex DNA molecules occuring du

What has caused evolution, What has caused evolution? 1) Different indi...

What has caused evolution? 1) Different individuals have dissimilar characteristics 2) These differences result in altering abilities to reproduce under local circumstances

Which photosystem-i or ii-most likely evolved first, Which photosystem-I or...

Which photosystem-I or II-most likely evolved first? Describe your reasoning. Photosystem II most likely evolved first, because it changes electrons lost from chlorophyll

What parameter can be calculate, In a twin study of 1000 MZ pairs, 625 pair...

In a twin study of 1000 MZ pairs, 625 pairs were found to have both twins with the same form of a given trait. In a study of 1000 DZ twins, 426 pairs were found to have both twins

What are the symptoms of rheumatic heart disease, Q. What are the symptoms ...

Q. What are the symptoms of Rheumatic Heart Disease? Symptoms generally appear after 1 to 6 weeks of the fever and sometimes the infection may have been too mild to have been r

Explain subclavian flap aortoplasty, Explain Subclavian Flap Aortoplasty ? ...

Explain Subclavian Flap Aortoplasty ? Initial steps are same as for resection and end-to-end anastomosis. After exposing a the entire length of intra thoracic segment of left s

Assignment of botany, habitat, habit, cell wall chemistry, reason why cell ...

habitat, habit, cell wall chemistry, reason why cell wall like this of Archaebacteria , eubacteria,fungi,algae,bryophytes ,pteridophyes, gymnosperms , angiosperms..

Evolutionary novelty presented by annelids, Q. What is the major evolutiona...

Q. What is the major evolutionary novelty presented by annelids? The main evolutionary novelty presented by the beings of the phylum Annelida is the coelom, the internal body c

Define the lens transparency in metabolism of lens, Define the lens transpa...

Define the lens transparency in metabolism of lens. Lens Transparency: a. Transparency depends on avoidance of large transitions of refractory index. This is in other wor

Explain adverse effects of fosamprenavir calcium, Explain adverse effects o...

Explain adverse effects of fosamprenavir calcium   Adverse effects are similar to those with amprenavir, but in clinical studies the incidence of nausea, vomiting and severe ra

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