Chemical Coordination and Integration
| 315
2. PÏTÜÏTÅRÝ GLÅÑD
Smallest
endocrine
gland
It is attached to
hypothalamus by
a stalk.
It is located in a
bony cavity called
sella tursica.
It is divided
into anterior
adenohypophysis
& posterior
neurohypophysis.
Posterior
pituitary
Neurosecretory
cells of the
hypothalamus
Neurohormone
Anterior pituitary
Hypothalamus
Axons
Å. ÅDËÑØHÝPØPHÝSÏS
It has 2 parts: Pars distalis and Pars intermedia
Pars distalis (Anterior pituitary) : It produces
1.
Somatotropin (Growth hormone, GH): For body growth.
01
Over-secretion of GH causes gigantism (abnormal
growth). Hyposecretion of GH causes dwarfism
(stunted growth).
Over-secretion of GH in adults (mainly in middle age)
causes acromegaly (severe disfigurement especially
of face) (NEET 2019). It leads to serious complications
and premature death. Early diagnosis of the disease is
difficult. It may be undetected for many years.
02
2.
Prolactin (PRL): Regulates growth of mammary glands and milk
production.
3.
Thyroid stimulating hormone (TSH): Stimulates secretion of thyroid
hormones from thyroid gland
4.
Adrenocorticotrophic hormone (ACTH): Stimulates the synthesis and
secretion of steroid hormones (glucocorticoids) from the adrenal cortex.
5.
Follicle stimulating hormone (FSH):
Stimulates gonadal activity. In males, FSH & androgens regulate
spermatogenesis.
In
females,
FSH
stimulates
growth
and
development of ovarian follicles.