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 the treatment of travelers diarrhea, Treatment of travelers'diarrhe...

Treatment of travelers'diarrhea  The most common cause of travelers' diarrhea, usually a self-limited illness lasting several days, is infection with noninvasive enterotoxigeni

What is iris coloboma, What is Iris Coloboma Coloboma is a congenital a...

What is Iris Coloboma Coloboma is a congenital abnormality due to non-fusion of the embryonic choroidal fissure. It can affect any part of the eye and may involve the optic ner

Fishes- regeneration in vertebrates, Fishes- Regeneration in Vertebrates ...

Fishes- Regeneration in Vertebrates Several different parts of the fish body will re-grow. Plucked scales are promptly replaced by new ones and amputated gill filaments can re

How do the cdnas vary from the original genes, How do the cDNAs vary from t...

How do the cDNAs vary from the original genes? A. The inserted cDNA copies lack enhancers, promoters and introns. B. The genomic structures of the original gene and the ins

Define criteria for assessment of niacin status, Define Criteria for Assess...

Define Criteria for Assessment of Niacin Status? Niacin status can be monitored by daily urinary excretion of methylated metabolites, especially the ratio of the 2-pyridone to

What is intercellular communication explain briefly, What is Intercellular ...

What is Intercellular Communication explain briefly? Both plant and animal cells have developed means of communication between cells. In animals, specialized areas of the cell

Respiration, explain the respiration that takes place in different organism...

explain the respiration that takes place in different organisms??

Autotomy and regeneration, Autotomy and Regeneration Shedding of body...

Autotomy and Regeneration Shedding of body parts in self-defense to avert the attention of the predator-enemy or in any other emergency is a type of autotomy (auto: self, tom

What is st depression with long diastolic filling, Q. What is ST Depression...

Q. What is ST Depression with Long Diastolic Filling? For the person with a slow heart rate and a long period of a diastole after a premature ventricular contraction, the next

Explain about ridge mapping, Explain about Ridge mapping Ridge relation...

Explain about Ridge mapping Ridge relationship is also critical especially in cases with multiple implants and fixed prosthesis, which is an advanced treatment procedure. But,

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