This Medicoapps Masterclass discusses about Pituitary. Various Topics Discussed are given Below 1. Anatomy of Pituitary 2. Development of Pituitary 3. Parts of Pituitary 4. Hormone Production by Pituitary 5. Blood Supply of pituitary 6. Hypothalamo-hypophyseal portal system

1. Pituitary Gland

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Pituitary Gland- Master Gland
Also k/a Hypophysis cerebri.
Shape- OVAL Size- measures 8x12 mm, & weighs about 500 mg.
Lies within hypophyseal / pituitary fossa or sella tursica of sphenoid bone .
Covered by Dural fold (diaphragm sellae)
Above connected with hypothalamus by infundibulum (pituitary stalk).

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Development of Pituitary Gland
Posterior lobe
NEUROHYPOPHYSIS
PROSENCEPHALON
(Forebrain)
PRIMITIVE ORAL CAVITY
(Stomodeum)
ROOT OF STOMODEUMFloor of DIENCEPHALON
NEUROECTODERMAL
DIVERTICULUM
RATHKE’S POUCH
FOREBRAIN
(Diencephalon)
PRIMITIVE ORAL
CAVITY
(Stomodeum)
Anterior lobe
ADENOHYPOPHYSIS

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Development of Pituitary Gland

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Pituitary Gland- Subdivision
Anterior lobe
ADENOHYPOPHYSIS
Posterior lobe
NEUROHYPOPHYSIS
Pars anterior or
Pars distalis or
Pars glandularis or
Anterior lobe proper
Pars posterior or
Pars nervosa or
Neural lobe or
Posterior lobe proper
Pars intermedia
( intermediate lobe).
Tuberal lobe ( pars tuberalis)
Infundibulum
(Infundibular stem)
Median eminence

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Pituitary Gland- Hormones
Hormone secreting cells:
1. Chromophills (acidophils, basophils)
2. Chromophobes and
3. Folliculostellate cells
Anterior lobe:

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Pituitary Gland- Hormones
Contain neuroglia like pituicytes which do not secrete any hormone.
(ADH & OXYTOCIN) are synthesized in hypothalamus
Transported to posterior lobe by hypothalamohypophyseal nerve fiber tract.
Stored in the axon terminals of neurohypophysis in Herring bodies before their release
Posterior pituitary

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Pituitary Gland- Blood Supply
Hypothalamo-hypophyseal Portal System
BLOOD SUPPLY
Single inferior hypophyseal artery (Br of ICA )
Several Superior hypophyseal artery (Br of ICA )
Helps Hypothalamus communicate with Ant. Pituitary via neurotransmitters
VENOUS DRAINAGE
Long and Short Portal Veins Inferior Hypophyseal Veins Dural Venous Sinuses

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Important Points
Anterior pituitary develops from Rathke's pouch.
Posterior pituitary develops from Neuroectodermal diverticulum.
Herring bodies are seen in Neurohypophysis.
Pituitary is supplied by a single inferior hypophyseal artery and several superior hypophyseal arteries.
Hypothalamohypophyseal Portal System. [Hypothalamus → Ant. Pituitary via neurotransmitters]

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Brain Teaser
Posterior lobe of Pituitary Gland develops from Rathke’s pouch. TRUE/ FALSE ??