1. Jai Narain Vyas University
Zoology department
M.Sc 2nd semester
2017
The pituitary gland
Submitted by
Bharat Nogia
2. Hypothalamus
Its is part of forebrain.
Develop from the ectoderm of embryo.
From its lower part , a nerve stalk arises
called infundibulum . It bears a pea- shaped gland
called pituitary gland. In this way hypothalamus
serves to connect brain and endocrine system.
4. The Hypothalamus and Endocrine Regulation
• Coordinating centers in the hypothalamus (master
gland) regulate the NS and endocrine system
activities by 3 different mechanisms
1) by secreting regulatory hormones that control
endocrine cells in the adenohypophysis (anterior lobe) of
the pituitary gland:
Releasing hormones (RH) stimulate production of one or
more hormones
Inhibiting hormones (IH) prevent the synthesis and
secretion of specific pituitary hormones
5. The pituitary gland
Hypophysis lies in sella turcica(present in
sphenoid bone).
Dual nature
It has Dual origin
2 lobs that is --- 1 Adenohypophysis
2 Neurohypophysis
Reddish grey in colour, oval shape about the
size of pea seed.
6. Hormones of pituitary gland
From adenohypophysis
GH- Growth Hormone
TSH- Thyrotropic Hormone
ACTH- Adrenocorticopin
FSH- Follicle Stimulating
Hormone
LH or ICSH- Luteinising
Hormone
PRL or LTH- Prolactin
Hormone
MSH-
From neurohypophysis
ADH- Antidiuretic Hormone
Oxytocin or Pitocin
8. What is hypophyseal portal system
• Various hormones secreted by hypothalums comes to
pituitary gland through Hypophyseal portal system,
which consist of hypophyseal protal vain. This vein
collects blood from various part of the
hypothalums(floor of diencephalon) and open into
anterior lobe of pituitary gland. From pituitary the vein
finally caries blood into the superior vena cava.
• hypophyseal portal vein from
hypothalums, brings with it, various hormones to the
pituitary glands. These hormone stimulate pituitary to
secrete own hormones.
9. Low magnification – the entire Pituitary Gland
Posterior Pituitary Pars Intermedia Anterior Pituitary
Pars TuberalisPituitary Stalk
11. GH- Growth Hormone
It is a peptide
hormone
It have 191 amino
acid residue
Molecular weight
about 22,000
bichemical function
Effects on growth
Effects on protein
metabolism
Effects on lipid
metabolism
12. Abnormalities of GH production
• Excessive production of GH causes gigantism
in children(giants) and acromeagaly in adults.
This usually occurs in the acidophil tumor of
pituitary gland.
• Impairment in the secretion of GH in growing
age casues dwarfism.
13.
14. TSH- Thyrotropic Hormone
• It is glycoprotein
hormone.
• Molecular weight
of about 30,000
FUNCTION
• Iodide pump
• Organification
• Increase the proteolysis
of thyroglobulin to
release T3 or T4 into the
circulation.
15. Adrenocorticotropic hormone
• It is peptide hormone , containing 39 amino acids.
Out of these 24 amino acids are common in all
species, while remaining 15 are species specific.
Biochemical Function
• This hormone stimulates the ‘zona fasciculata’
and ‘zona reticularis’ of the cortex of the adrenal
gland to produce it hormones ‘cortisol’
• Increase the production of ACTH during
emotional and physical stress.
16. FSH- Follicle Stimulating Hormone
It is a glycoprotein's
hormone
its molecular weight
about 32,000
Biochemical function
• in females it promates the
growth of graafian follicle
and stimulates it to secrete
progesterone.
• Promats the growth of
oogenesis.
• In Male it promotes the
growth of follicular cells
and spermatogenesis.
17. LH or ICSH- Luteinising Hormone
It is glycoprotein's
hormone
its molecular weight
about 32,000
Bichemical function
• in females it promotes
the growth of corpus
leuteum and stimulates it
to secrete progesterone.
• In males it stimulates the
growth and development
of interstitial cells of
leydig and stimulates
them to secrete
testosterone.
18. Prolactin hormone (PRL) or
Mammotropin or LTH
• Peptide hormone , contain 198 amino acid
Biochemical function
Most important effect of prolactin it to convert
the ordinary brest, into milk forming glands. It
therefore cause proliferation of lactiferous
tissues of the breast and promotes growth.
Secretion of prolactin very high during
pregnancy.
stimulate the process of milk formation.
19. Hormones secreted by
neurohypophysis
Forming a ‘hypothalamico-hypophyseal tract’.
Neurohypophysis is merely a storage organ.
These release 2 important hormone- these are
1- Antidiuretic hormone (vesopressin, pitressin )
2- Oxytocin or pitocin
20. Antidiuretic hormone (vasopressin,
pitressin )
Small peptide hormone, consisting 9 amino
acids.
Biochemical function
Is to reabsorb as much water as possible
form DCT of nephron. ADH concentrates the
urine, deficiency of ADH leads to diabetes
incipedus,(in which urine gets diluted and
frequency of urination becomes very high).
21. Oxytocin or pitocin
• It plays an important role in the birth of baby,
at the time of parturition, it initiates
contraction in the uterine muscle, which create
labour pain.
• It stimulate the breast to eject the milk out,
therefore it is also called ‘milk ejecting
hormone’.
• During parturition in woman, the secretion of
oxytocin is at its maximum.
22. Pancreas
• About 15 cm in length and 85 gm in weight.
• Derived from the endoderm of embryo.
• It is mix gland, I.e., it has both endocrine as
well as exocrine activity.
25. Hormone of pancreas
Insulin
• Secreted by beta cells of islets of langerhance. It was
discovered by C.H.Best(1922) and F. banting. Its amino acid
sequence was determined by Sanger(1952).
26. Biochemical function of insulin
• Also known as ‘ hypoglycemic factor’ because
its most important function is to lower the
blood glucose level. For this, insulin
increases glycogenesis in liver
increases the uptake of glucose by body
cells.
Lack of insulin in body promotes glycogenolysis (sorbitol).
Increases lipogenesis .
Inhibits formation of ketone bodies.
27. Glucagon
• Is it produced by alpha cells of islets of
langerhans. It is also a peptide hormone,
containing only 29 amino acids. Its molecular
weight is 2495.
Biochemical function
It is called ‘hyperglycemic factor’ or ‘anti-insulin
hormone’.
It promotes glycogenolysis, gluconeogenesis,
enhance lipolysis
Its paracrine effect.
28. Disorders of pancreas
diabetes mellitus(hyperglycemia)
• . Caused due to pancreatic disorder
• Is occur when pancreas fails to release
adequate amount of insulin. So passing out
glucose with urine, this called
glycosuria(diabetes mellitus)
• polydipsia- removel of glucose follwed by
exessive amount of water from body, this
result in increased thirst.
• Diabetic comma.
29. Hyopglycemia
• It occurs due to oversecretion of insulin or
poor secretion of glucagon.
• Symptoms of hypoglycernia include weakness,
profuse sweating, irritability, cocnfusion,
unconsciouness and convulsions.
• A quick intake of sugar or glucose may give
temporary releaf.
30. References
• Conceptual biology
( Agrawal)
• Essential of biochemistry
( U. satyanarayana)
( U. Chakrapani)
• Zoology
( Prof. A.K.Purohit )
(Dr. H. Ram)
