Download 1-JAN 18 PG

Dr. Sarah Al-Sultan
• Describe the position of the pituitary gland.
• List the structures related to the pituitary gland.
• Differentiate between the lobes of the gland.
• It is referred to as the master of endocrine glands.
• It is a small oval structure 1 cm in diameter.
X-RAY SKULL: LATERAL
VIEW
SAGITTAL SECTION OF
HEAD & NECK
Pituitary
gland
Hypophyseal fossa
Sphenoidal air sinus
It lies in the middle cranial fossa
It is well protected in Sella Turcica
(hypophyseal fossa)
Sella turcica
Optic chiasma
Mamillary body
Body of sphenoid
•
It is lies between optic chiasma (anteriorly) & mamillary
bodies (posteriorly).
A fold of dura mater (Diaphragma sellae) covers the pituitary
gland & has an opening for passage of infundibulum
(pituitary stalk) connecting the gland to hypothalamus.
IMPORTANT RELATIONS
•
•
•
SUPERIOR: Diaphragma sellae
INFERIOR: Sphenoidal air sinuses
LATERAL: Cavernous sinuses
Hypothalamo-hypophyseal
tract
The gland is subdivided into:
1)Anterior lobe (Adenohypophysis): It is the True gland, synthesize and
Secretes hormones.
2) Posterior lobe (Neurohypophysis): connected to hypothalamus through
hypothalamo-hypophyseal tract, Stores hormones secreted by hypothalamic
nuclei.
ARTERIES:
Superior & inferior hypophyseal arteries (branches of internal carotid
artery)
VEINS:
Hypophyseal veins drain into Cavernous Sinuses.
a hypothalamohypophseal
portal vessel
Superior hypophyseal artery: Supplies infundibulum & forms a
capillary network from which vessels pass downward & form
sinusoids into the anterior lobe of pituitary gland (Hypophyseal
portal system).
Inferior hypophyseal artery: Posterior lobe of pituitary gland.
Hormone-releasing & inhibiting
factors produced by
hypothalamus use Hypothalmohypophyseal Portal vessels to
reach the anterior lobe of
pituitary gland.
It is consists mainly of
neuronal projections
extending from the supraoptic
and paraventricular nuclei.
The gland is composed of two parts:
 Anterior lobe (adeno hypophysis)
 Posterior lobe (neuro hypophysis)
Normal size:
 Weight: 0.5g.
 Height: 4-8 mm
 Anterior posterior: 516 mm.
Hormonal dysfunction
 Cushing syndrome
 Growth abnormalities e.g. Growth
hormone deficiency, acromegaly
Visual abnormality.
Headache.
Question
What is the best modality to image the pituitary
gland ?
A. X ray
B. CT scan
C. MRI
D. US
E. Nuclear medicine
Question
What is the best modality to image the pituitary
gland ?
A. X ray
B. CT scan
C. MRI
D. US
E. Nuclear medicine
CT scan
MRI
CT scan
MRI
1
2
3
4
5
6
1
2
3
4
5
6
1-Optic sulcus
2- Anterior clinoid
process
3-Floor of sella turcia
(Pituitary fossa)
4- Posterior clinoid
process
5- Dorsum sella
6- Sphenoid sinus
4
3
5
2
6
1
1- Pituitary gland
2- Sphenoid sinus
3- Optic chiasm
4- Hypothalamus
5- Pituitary stalk
6- Claivus
4
3
5
2
6
1
NORMAL
PITUITARY
ADENOMA
3
2
1
4
5
6
3
2
1
4
5
6
Pituitary
stalk
Carotid
artery
Cavernous
sinus
Optic
chiasm
Pituitary
gland
Sphenoid
sinus