ANTERIOR PITUITARY GLAND

ANTERIOR PITUITARY GLAND

1. DR NILESH KATE
MBBS,MD
ASSOCIATE PROF
DEPT. OF PHYSIOLOGY
PITUITARY
GLAND

2. OBJECTIVES.
Introduction and functional anatomy.
Anterior pituitary hormones
Growth hormones
Applied aspects.
Wednesday, June 1, 2016

3. INTRODUCTION AND
FUNCTIONAL ANATOMY.
Hypothalamo-
pituitary unit–
important component
of endocrine system
Controls – Growth,
Lactation, Fluid
balance, thyroid,
adrenals & gonads.
Wednesday, June 1, 2016

4. GROSS ANATOMY
Pituitary Gland –
hypophysis cerebri
Wt – 0.5 gm
Location –
hypophyseal fossa
Suspended by
pituitary stalk which
connects it to
hypothalamus.
Wednesday, June 1, 2016

5. DEVELOPMENT.
Anterior pituitary –
Ectodermal origin.
From Rathke’s pouch
Upward out pouching
from roof of primitive oral
cavity.
Posterior pituitary.
Lowered out pouching
From Neuroectodermal
tissues of central
hypothalamus.
Wednesday, June 1, 2016

6. PARTS OF PITUITARY GLAND.
Adenohypophysis
Neurohypophysis.
Pituitary stalk.
Wednesday, June 1, 2016

7. ADENOHYPOPHYSIS
Forms 80%
3 parts
Pars Distalis – main
bulk, highly vascular
Pars Intermedia –
middle, avascular zone
Pars Tuberalis – most
vascular, contains
secretory cells.
Wednesday, June 1, 2016

8. NEUROHYPOPHYSIS.
Post lobe – Neural
structure.
3 parts
Pars Posterior – pars
nervosa , forms main bulk.
Infundibular Stem – arising
from median eminance
Median Eminance – small
portion from base of
hypothalamus..
Wednesday, June 1, 2016

9. PITUITARY STALK.
Median eminence &
Infundibulum forms
neural stalk.
Surrounded by Pars
Tuberalis of
Adenohypophysis.
Wednesday, June 1, 2016

10. INTERMEDIATE LOBE
Rudimentary & does not secrete
Melanocyte stimulating
hormones(MSH).
Humans contains few
Melanocyte containing melanin
granules.
ACTH has weak MSH like
activity, so in Addison's disease
Hyper secretion of ACTH, there
is hyper pigmentation of skin.
Wednesday, June 1, 2016

11. HISTOLOGICAL STRUCTURE
Adenohypophysis
Chromophobes - Agranular
Chromophils – Granular
Acidophils (35%)
Somatotrophs
Mammotrophs.
Basophils (15%)
Corticotrophs, Thymotrophs,
Gonadotrophs.
Folliculostellate cells
Capillary network.
Wednesday, June 1, 2016

12. HISTOLOGICAL STRUCTURE
Neurohypophysis.
Unmyelinated nerve
fibers – axons in
supraoptic &
paraventricular nuclei of
hypothalamus.
Pituicytes – Special types
of supporting cells.
Glial cells – like Astrocytes
& Oligodendrocytes.
Wednesday, June 1, 2016

13. BLOOD SUPPLY OF PITUITARY
GLAND
ARTERIAL SUPPLY
Internal carotid artery
(sup & inf hypophyseal
branches)
Anterior cerebral artery.
Posterior cerebral
artery.
VENOUS DRAINAGE
Cavernous sinus
Jugular veins.
Wednesday, June 1, 2016

14. HYPOTHALAMO-HYPOPHYSEAL
PORTAL SYSTEM.
From superior hypophyseal
artery, form capillary network.
Drained by long portal veins in
Infundibulum.
Break into capillaries as
sinusoids of pars anterior as
portal system
Provide link between ant &
post pituitary.
Wednesday, June 1, 2016

15. HYPOTHALAMIC PITUITARY
RELASHIONSHIP
Hypothalamo-
hypophyseal tract.
Tubero-infundibular
tract and
hypothalamo-
hypophyseal portal
system.
Wednesday, June 1, 2016

16. HYPOTHALAMO-
HYPOPHYSEAL TRACT.
Axons of large Neuro
secretory cells of supraoptic
& paraventricular nuclei of
hypothalamus.
At axon terminal form
Herring bodies.
Secrete peptide hormones &
stored in Neuro secretory
granules in nerve terminals.
Released in inferior
hypophyseal artery.
Wednesday, June 1, 2016

17. TUBERO-INFUNDIBULAR TRACT AND
HYPOTHALAMO-HYPOPHYSEAL
PORTAL SYSTEM.
Wednesday, June 1, 2016

18. Wednesday, June 1, 2016

19. ANTERIOR PITUITARY
HORMONES
ANTERIOR PITUITARY -
master endocrine organ
Adenohypophysis
hormones
Growth hormone family.
Glycoprotein hormone
family.
Pro-opiomelanocortin
peptides family.
Wednesday, June 1, 2016

20. Wednesday, June 1, 2016

21. GROWTH HORMONE FAMILY.
Growth hormone
Prolactin.
Human chorionic
Somatomammotropin.
Wednesday, June 1, 2016

22. GLYCOPROTEIN HORMONE
FAMILY.
Thyroid stimulating hormone
Luteinizing hormones
Follicle stimulating hormones.
Wednesday, June 1, 2016

23. PRO-OPIOMELANOCORTIN
PEPTIDES FAMILY.
Derived from single precursor – Pro-
opiomelanocortin
Adrenocorticotropic hormone
Melanocyte stimulating hormone
β- lipotropin
 β-endorphin
Wednesday, June 1, 2016

24. OBJECTIVES WE HAVE SEEN
Pituitary gland – macroscopic & Microscopic
structure.
Relationship with Hypothalamus.
Releasing & Inhibiting Hormones.
Anterior pituitary gland
Cells, secretions and different hormones.
Wednesday, June 1, 2016

25. Thank you.
Wednesday, June 1, 2016