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

Explain pr murmur characterstic and graham steel murmur, Explain PR Murmur ...

Explain PR Murmur characterstic and graham steel murmur? PR Murmur Characteristic: Blowing, decrescendo murmur heard loudest in 2nd and 3rd left intercostal space with increa

Evaporative cooling, Normal 0 false false false EN-IN ...

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

Explain the general small size of arthropods, How does the presence of exos...

How does the presence of exoskeleton explain the general small size of arthropods? As they have exoskeleton and periodic ecdysis, the growth of arthropods is limited to avoid t

How is price mechanism or supply and demand concerned, How is price mechani...

How is price mechanism or supply and demand concerned?   The price mechanism or supply and demand: The price mechanism or supply and demand is concerned with how buyers

Explain the spermatogonium and spermatocyte I, What is the difference betwe...

What is the difference between spermatogonium and spermatocyte I? The male germ cells are the spermatogonia (diploid cells, 2n) located in the testicles. They mature and by mea

Fatty acid metabolism, Fatty Acid Metabolism The body has a limited sup...

Fatty Acid Metabolism The body has a limited supply of glucose associative to the energy stored as fat. There are 3 sources of fatty acids for energy metabolism within animals;

Respiration, how does respiration in animals occur? what is respiration? wh...

how does respiration in animals occur? what is respiration? what are the common types of respiration?

Define clinical feature and medical complication for bulimia, Define Clinic...

Define Clinical Features and Medical Complications for bulimia? Unlike, anorexia nervosa, in bulimia you will find that symptoms are more difficult to detect because patients a

Spirochetosis (tick fever), S p ir ochetosis (tick fever) This is di...

S p ir ochetosis (tick fever) This is disease of young birds under poor management mostly reared as backyard poultry caused by a spiral bacterium, Borrelia anserina and tr

Erythrocytic cycle, Erythrocytic cycle The cycle that takes place i...

Erythrocytic cycle The cycle that takes place in the body of man who is considered as secondary host is called the erythrocytic cycle. The first stage of the cycle begins

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