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

Foods for phenylketonuria patient, Q. Foods for phenylketonuria patient? ...

Q. Foods for phenylketonuria patient? The majority of foods for a PKU patient should come from the bottom half of the pyramid. As you may have observed, this contains the pheny

How can we examine the chromosomes, Is it more indicated for a geneticist d...

Is it more indicated for a geneticist desiring to map the X chromosome of the mother of a given family (the researcher does not have access to her DNA, only access to the genetic m

Tolerance range, what is tolerance range ? define and explain it ?

what is tolerance range ? define and explain it ?

Venting of the heart in myocardial protection, Venting of the Heart :  It ...

Venting of the Heart :  It is important that heart does not distend during cardio pulmonary bypass. This is prevented by venting of the left side of the heart by inserting a cannu

Where in the body is the thyroid gland located, Q. Where in the body is the...

Q. Where in the body is the thyroid gland located? The thyroid is located in the anterior cervical region (frontal neck) in just below the larynx and front of the trachea and i

What are biotic factors, What are biotic factors? Biotic factors are li...

What are biotic factors? Biotic factors are living beings (plants, microorganisms and animals) that are part of a given environment.

What are analogies for a nucleolus, What are analogies for a nucleolus? ...

What are analogies for a nucleolus? If the nucleolus is the president of a factory then the nucleolus is the manager

Animal genetics and breeding, POULTRY BREEDING Poultry breeding has acq...

POULTRY BREEDING Poultry breeding has acquired pre-eminence over all other domesticated livestock enterprises. Production level of layer and broiler type of chicken touched spe

Determine the term - neuropsychologists and neurologists, Determine the ter...

Determine the term - Neuropsychologists and neurologists Neuropsychologists and neurologists studying behaviour have been greatly concerned with localisation of function in the

What is the importance of biotin, What is the Importance of biotin Biot...

What is the Importance of biotin Biotin is involved in a number of important metabolic reactions, probably as coenzymes. Deficiency symptoms are manifest as degenerative cha

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