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

Spermiogenesis - spermatogenesis, Spermiogenesis - Spermatogenesis At ...

Spermiogenesis - Spermatogenesis At the end of the meiosis the spermatids appear as simple spherical cells with a centrally located nucleus. Their differentiation into sperm r

Illustrate about the neuropsychological battery, NEUROPSYCHOLOGICAL BATTERY...

NEUROPSYCHOLOGICAL BATTERY The battery was published in 1980 by Western Psychological Services and is now extensively used in clinical and research applications. An alternate

What are the factors to an actual shift in the demand curve, What are the f...

What are the factors to an actual shift in the demand curve? Factors that cause an actual shift within the demand curve are as follows: When prices rise or fall that would c

A haploid cell attempted to perform meiosis, What problem would most likely...

What problem would most likely to occur if a haploid cell attempted to perform meiosis? The cell could not replicate its DNA prior to meiosis.The cell could not pair homologous

Fertilization, Fertilization is the fusion of the two gametes (sperm and o...

Fertilization is the fusion of the two gametes (sperm and ovum) to produce a zygote which develops into the new individual with a genetic heritage derived from both the parents. S

Define percentages of body fat values for athletes, Define Percentages of b...

Define Percentages of body fat values for athletes? Percentages of body fat values for athletes vary depending on the sex of the athlete and the sport itself. Male athletes par

Which type of gamete produced by a heterozygous individual, Which is the ty...

Which is the type of gamete produced by a heterozygous individual? What is the genotypical proportion of these gametes? Heterozygous individuals, for instance, AA, produce two

Explain disadvantage of colonies at different dilution, Explain the Disadva...

Explain the Disadvantages of Colonies Obtained At Different Dilution 1. Heat sensitive microorganisms may be damaged by melted agar, giving low viable count as compared to spre

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