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Histological structure of pituitory gland

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The pituitary gland has two main parts - the adenohypophysis and neurohypophysis. The adenohypophysis contains the pars distalis, pars tuberalis, and pars intermedia. The pars distalis is the largest part and contains chromophils like somatotrophs and mammotrophs that secrete growth hormones, as well as chromophobes that secrete ACTH. The neurohypophysis contains the pars nervosa and secretes oxytocin and anti-diuretic hormone. The pituitary gland regulates many important bodily functions through the hormones produced by its various cell types located within its distinct anatomical regions.

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Histological Structure of Pituitary gland Asst. Prof Chetana Kanekar M.Sc ( SET life sciences)
Introduction The pituitory gland or hypophysis is structurally and functionally most complex endocrine gland. Located in th ebrain attached by slender hypophysial or infundibular stalk,just behind the optic chiasma. The pituitory gland has double origin as it is partly derived from oral ectoderm and partly from the brain. The pituitory gland has two main parts: I. Adenohypophysis II. Neurohypophysis
Histological structure of pituitory gland
Adenohypophysis I. It is also called glandular lobe. II. This is anterior two third of the gland which is formed from stomodeal portion. III. It has following parts Pars distalis, Pars tuberalis, Pars intermedia Neurohypophysis I. This is formed from neural ectoderm. II. It has following parts: Pars nervosa,Infundibulum.
Chromophils These are ovoid cells with granular cytoplasm nuclei.They take up acid or basic stains and are classified into two types a. Acidophils ( alpha cells):- Acidophils are rounded or ovoid cells 10 to 20 micron have cytoplasm that stains red or orange b. Acidophils are of two types Somatotrophs:- These cells secrete somatotropin hormones and growth hormaones Mammotrophs( leutotrophs or prolactin cells):- These cells secrete prolactin hormone.
Adinohypophysis Pars distalis:-Pars distalis or anterior lobe is the largest(75%)part of pituitory gland supported by collagenous capsule. In this region ,two major types of cells occur namely chromophils & chromophobes .
Basophils( beta cells):- They are irregular shaped and stain with basic dyes. Basophils are of two types i. Thyrotrophs :- These cells secrete thyrotrophic hormone ii. Gonadotrophs :- These cells secrete gonadotrophic hormone .i.e. FSH ( Follicle stimulating hormone ) and LH ( leutinizing Hormone)
Chromophobes (chief cells) These cells are spherical ,elongated and irregular cells and appear in groups near center of cords These cells contain light staining cytoplasm. These cells produce adrenocorticotropic hormone(ACTH)
Pars tuberalis Pars tuberalis is a layer of cuboidal cells that covers the part of stalk and tuberal area of the brain. It is highly vascular. Not known whether these cells produce any hormon or not.
Pars Intermedia It is a narrow region between pars distalis and pras nervosa. It contains a stratum of epithelial cells which is formed by several layers of polygonal cells and they are basophilic. The pars intermedia secrete melanonocytye stimulating hormone in lower vertebrates like fish and amphibians ,but in the mammals the function of MSH is obscure.
Fig
Neurohypophysis It is formed by ventral cylindrical outgrowth from the floor of the diencephalon,which forms the stalk and posterior 1/3 of the pituitory gland. The posterior 1/3 of the gland ,whioch is formed by swollen end of ventral outgrwoth, is called pars nervosa or infundibular process. The cells of neural lobe are called pituicytes. Two hormones Oxytoxin and Anti-diuretic are secreted from neurohypophysis.
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Histological structure of pituitory gland

  • 1. Histological Structure of Pituitary gland Asst. Prof Chetana Kanekar M.Sc ( SET life sciences)
  • 2. Introduction The pituitory gland or hypophysis is structurally and functionally most complex endocrine gland. Located in th ebrain attached by slender hypophysial or infundibular stalk,just behind the optic chiasma. The pituitory gland has double origin as it is partly derived from oral ectoderm and partly from the brain. The pituitory gland has two main parts: I. Adenohypophysis II. Neurohypophysis
  • 4. Adenohypophysis I. It is also called glandular lobe. II. This is anterior two third of the gland which is formed from stomodeal portion. III. It has following parts Pars distalis, Pars tuberalis, Pars intermedia Neurohypophysis I. This is formed from neural ectoderm. II. It has following parts: Pars nervosa,Infundibulum.
  • 5. Chromophils These are ovoid cells with granular cytoplasm nuclei.They take up acid or basic stains and are classified into two types a. Acidophils ( alpha cells):- Acidophils are rounded or ovoid cells 10 to 20 micron have cytoplasm that stains red or orange b. Acidophils are of two types Somatotrophs:- These cells secrete somatotropin hormones and growth hormaones Mammotrophs( leutotrophs or prolactin cells):- These cells secrete prolactin hormone.
  • 6. Adinohypophysis Pars distalis:-Pars distalis or anterior lobe is the largest(75%)part of pituitory gland supported by collagenous capsule. In this region ,two major types of cells occur namely chromophils & chromophobes .
  • 7. Basophils( beta cells):- They are irregular shaped and stain with basic dyes. Basophils are of two types i. Thyrotrophs :- These cells secrete thyrotrophic hormone ii. Gonadotrophs :- These cells secrete gonadotrophic hormone .i.e. FSH ( Follicle stimulating hormone ) and LH ( leutinizing Hormone)
  • 8. Chromophobes (chief cells) These cells are spherical ,elongated and irregular cells and appear in groups near center of cords These cells contain light staining cytoplasm. These cells produce adrenocorticotropic hormone(ACTH)
  • 9. Pars tuberalis Pars tuberalis is a layer of cuboidal cells that covers the part of stalk and tuberal area of the brain. It is highly vascular. Not known whether these cells produce any hormon or not.
  • 10. Pars Intermedia It is a narrow region between pars distalis and pras nervosa. It contains a stratum of epithelial cells which is formed by several layers of polygonal cells and they are basophilic. The pars intermedia secrete melanonocytye stimulating hormone in lower vertebrates like fish and amphibians ,but in the mammals the function of MSH is obscure.
  • 11. Fig
  • 12. Neurohypophysis It is formed by ventral cylindrical outgrowth from the floor of the diencephalon,which forms the stalk and posterior 1/3 of the pituitory gland. The posterior 1/3 of the gland ,whioch is formed by swollen end of ventral outgrwoth, is called pars nervosa or infundibular process. The cells of neural lobe are called pituicytes. Two hormones Oxytoxin and Anti-diuretic are secreted from neurohypophysis.