Pituitary gland, Biology

Assignment Help:

PITUITARY GLAND (HYPOPHYSIS CEREBRI) -

  • It develops from ectoderm of the embryo.
  • The pituitary gland is located just below the hypothalamus. The pituitary gland is situated in a depression the sella turcica of sphenoid bone of the skull.
  • The pituitary gland is the smallest endocrine gland. It is about 1.3 cm in diameter and weighs about half a gram.
  • The gland is attached to the brain by a stalk the infundibulum which is continuous with the hypothalamus above.
  • Adenohypophysis or pars distalis and the posterior lobe or neurohypophysis or pars nervosa.
  • Adenohypophysis originates as Rathke's pouch from dorsal wall of stomodaeum in the embryo, but later its connection with the stomodaeum disappears.
  • The neurohypophysis originates as an outgrowth from the floor of the diencephalon.
  • A third lobe, called the intermediate lobe or pars intermedia is a part of adenohypophysis.

1108_pituitary gland.png

  • Adenohypophysis comprises about 75% part of the pituitary gland.
  • The hypophysial portal veins carry blood containing neurohormones (releasing factors) from the hypothalamus to tbe adenohypophysis.
  • Neurohypophysis comprises about 25% part of the pituitary gland. The axons of neurosecretory cells (secretory neurons) extend into the neurohypophysis where these axons terminate as axon terminals. These terminals are embedded in a neuroglial tissue formed of large and branched cells called pituicytes.
  • No hormones are synthesized in neurohypophysis but two hormones, synthesized in the hypothalamic neurosecretory cells remain stored in very small vesicles in the axons and terminals. These vesicles are called Herring bodies.

Related Discussions:- Pituitary gland

Taxonomy, how do i classify mythical creatures into a web?

how do i classify mythical creatures into a web?

Relate fibro-osseous retention and osseointegration, Fibro-osseous Retenti...

Fibro-osseous Retention V/S Osseointegration Fibro-osseous retention is the tissue to implant contact interposition of the healthy, dense collagenous tissue between the implant

Genetics, how to determine that the phenotype of a wild type is due to the ...

how to determine that the phenotype of a wild type is due to the action of one or two genes?

Explain the importance of parent material, Explain the importance of parent...

Explain the importance of parent material Part of  these weathered minerals are transported  away by volcanoes, wind, water, ice, and waves etc. These very factors transport th

Applications of genetic engineering, Q. Applications of genetic engineering...

Q. Applications of genetic engineering? Applications of genetic engineering in different fields are: • Agriculture: Crops having larger yields, drought -and disease -resis

Define the control of tear production, Define the control of tear productio...

Define the control of tear production. Control of Tear Production The lacrimal secretary system was initially thought to be comprised of two parts, basic secretors and r

Define the effect of dietary fibre on nutrient absorption, Define the effec...

Define the effect of dietary fibre on Nutrient Absorption? Nutrient Absorption: Inclusion of fibre has been shown to retard the absorption of some nutrients. The inclusion of v

Explain the mechanisms of endosseous integration, Mechanisms Of Endosseous ...

Mechanisms Of Endosseous Integration Three terms may be used to describe individual aspects of bone formation process that can occur around implants. They are Osteoconduction,

Metabolic events, Metabolic Events Let us now examine the changes that...

Metabolic Events Let us now examine the changes that occur in the seeds after they imbibe water. In general, the most important metabolic events are: Degradation

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