Post on 14-Feb-2018
DEVELOPMENT &
STRUCTURE OF THE
PITUITARY GLAND
DR TATHEER ZAHRA
ASSISTANT PROFESSOR ANATOMY
PITUITARY GLAND/
HYPOPHYSIS CEREBRINomenclature
Master gland
Size
Shape
Weight
Capsule
Location
Relations
ANTERIOR
• Duramater
• Sphenoidal air sinuses
POSTERIOR
• Duramater
• Dorsum sallae
• Sphenoidal air sinuses
• Basilar artery
• Pons
SUPERIOR
• Diaphragmasellae
• Optic chiasma
• 3rd ventricle
INFERIOR
• Dural floor of the fossa
• Intercavernoussinus
• Body of sphenoid
• Sphenoidal air sinuses
LATERAL
• Duramater
• Cavernous sinus
NEUROVASCULAR SUPPLY
Several superior hypophyseal
arteries Inferior hypophyseal artery
Primary capillary plexus
Secondary capillary plexus
Venous drainage
Superior & inferior
hypophyseal veins
Cavernous sinus
Nerve supply ~ Postsynaptic fibers
of ANS (Vasomotor to Ant. Lobe),
Hypothalamic nuclei (Post. Lobe)
Fenestrated capillaries
Sinusoidal
capillaries
CONNECTIONS OF THE HYPOTHALAMUS
WITH PITUITARY GLAND
HYPOTHALAMO-HYPOPHYSEAL
TRACT HYPOPHYSEAL PORTAL SYSTEM
DEVELOPMENT OF THE
PITUITARY GLAND
ADENOHYPOPHYSIS
• ECTODERM OF THE STOMODEUM OROPHARYNX/ RATHKE’S POUCH
NEUROHYPOPHYSIS
• NEUROECTODERM OF THE FLOOR OF THE 3RD VENTRICLE/ DIENCEPHALON
3RD WEEK
5TH WEEK
6TH WEEK
HYPOPHYSEAL DEFECTS
Pharyngeal Hypophysis
Craniopharyngiomas
Basipharyngeal Canal
Microadenoma (< 1cm in diameter)
Macroadenoma (> 1cm in diameter)
Mechanical effects of tumors ~ Neurological defects, Bitemporal hemianopia (Tunnel
vision), Headache, Epistaxis, CSF Rhinorrhea, Hydrocephalus etc.
Treatment options ~ Medication, Surgery, Radiotherapy, Combination
SURGICAL APPROACHESTRANS-SPHENOIDAL APPROACH (via orbit or nasal septum)
CRANIOTOMY FOR SUB-FRONTAL APPROACH
CRANIOTOMY FOR TRANS-CAVERNOUS APPROACH
LE FORT MAXILLOTOMY
INTRAOPERATIVE MRI (IMRI)
TRANS-SPHENOIDAL
APPROACH
Through orbit: Via ethmoidal air cells after raising the periosteum from the medial wall of the orbit
Through nasal septum:
*By elevating the nasal mucosa from the nasal septum & removing the septum (the nasal cavity itself is not entered)
*Maxilla-premaxilla (Cottle) approach by preserving the caudal end of the nasal septum & the anterior nasal spine
CRANIOTOMY FOR
SUB-FRONTAL APPROACH
CRANIOTOMY FOR
TRANS-CAVERNOUS
APPROACH
Trans-cavernous Approach
LE FORT MAXILLOTOMY
INTRAOPERATIVE
MRI (IMRI)
Pre operative:
Polytomograms of sella
& sphenoid sinus
Bilateral carotid
angiography
CT scan
Pneumoencephalography
Intra-operative:
Operating microscope
Intra-operative x-ray
control with image
intensifier
ORGANIZATIONADENOHYPOPHYSIS
(Glandular part)
Pars tuberalis
Pars distalis-pars
anterior
Pars intermedia
NEUROHYPOPHYSIS
(Nervous part)
Pars nervosa
Infundibulum
(Infundibular stem &
Median eminence)
ADENOHYPOPHYSIS
PARS DISTALIS
PARS TUBERALIS
PARS INTERMEDIA
PARS DISTALIS
75% of the mass of the hypophysis
Highly vascular
Common stains allow recognition of 3 cell
types
Folliculostellate cells
Chromophobes ~ 50 %
2 types of chromophils
Acidophils ~ 35-40 %
Basophils ~ 10-15 %
ACIDOPHILS
SOMATOTROPES/
GH CELLSMAMMOTROPES/
PRL CELLS
50% 15-20%
REGULATION OF SECRETIONSOMATOTROPES/
GH CELLS
MAMMOTROPES/ PRL
CELLS
PROLACTIN
TRH
VIP
DOPAMINE
HYPOTHALAMUS
GHRH
SOMATOTROPES
GH
BASOPHILS
GONADOTROPES/
FSH & LH CELLS
THYROTROPES/
TSH CELLS
CORTICOTROPES/
ACTH CELLS
10%
5%
15-20%
Pars distalis: Crystal scarlet, aniline blue
& Martius yellow
REGULATION OF SECRETION
GONADOTROPES/
FSH & LH CELLS
THYROTROPES
/ TSH CELLS
HYPOTHALAMUS
GnRH
GONADOTOTROPES
FSH & LH
CORTICOTROPES
/ ACTH CELLS
HYPOTHALAMUS
TRH
THYROTROPES
TSH
HYPOTHALAMUS
CRH
CORTICOTROPES
POMC
ACTH
PARS TUBERALIS
Folliculostellate
cells
Basophils
Corticotropes
Gonadotropes
PARS INTERMEDIA
Folliculostellate
cells
Chromophobes
Basophils
Corticotropes
Black arrow -
Rathke's Pouch
Blue arrow –
Adenohypophysis
Red arrow –
Neurohypophysis
SUMMARY OF SECRETORY CELLS OF ADENOHYPOPHYSIS
PIHPRH
+ -
SUMMARY OF REGULATION OF SECRETION OF ADENOHYPOPHYSIS
NEOROHYPOPHYSIS
NEUROHYPOPHYSIS
INFUNDIBULUM/ NEURAL STALK
MEDIAL EMINENCE STEM
PARS NERVOSA
INFUNDIBULUM/ PITUITARY
STALK
PARS NERVOSA
HERRING BODIES
E/M of Herring bodies of rat posterior lobe
HORMONES OF THE PARS
NERVOSA
VASSOPRESSIN BY SUPRAOPTIC
NUCLEUS
OXYTOCIN BY PARAVENTRICULAR
NUCLEUS
CONTROL OF SECRETION
FACTORS AFFECTING
SECRETION:
a. Osmotic stimuli
b. Volume effect
c. Other stimuli:
Pain
Nausea
Surgical stress
Drugs:Morphine
Nicotine
Barbiturate
Alcohol
Opiate antagonist
Hypertonicity Hypovolemia
Osmoreceptors Baroreceptors
Hypothalamus
Thirst
REFERENCESThe Developing Human, Clinically Oriented Embryology, By KEITH L.
MOORE - Latest Edition
LANGMAN’S Embryology, By T.W.SADLER - Latest Edition
LAST’S Anatomy Regional & Applied, By CHUMMY S.
SINNATAMBY - Latest Edition
Clinically Oriented Anatomy, By KEITH L. MOORE - Latest Edition
Clinical Anatomy By Regions, By RICHARD S. SNELL - Latest Edition
Basic Histology Text & Atlas, By LUIZ CARLOS JUNQUEIRA &
JOSé CARNEIRO - Latest Edition