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