Transcript RADIOLOGY ANATOMY OF THE PITUITARY GLAND

Dr. fahad albadr
At the end of the lecture, students should
be able to:
 Describe the position of the pituitary
gland.
 List the structures related to the pituitary
gland.
 Differentiate between the lobes of the
gland.
PITUITARY GLAND
(HYPOPHYSIS CEREBRI)
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
POSITION
It lies in the middle cranial
fossa
It is well protected in sella turcica
(hypophyseal fossa) of body of
sphenoid
Sella turcica
Optic chiasma
Mamillary body
Body of sphenoid

it 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
SUBDIVISIONS OF PITUITARY GLAND
Hypothalamo-hypophyseal
tract
The gland is subdivided into:
1) Anterior lobe (Adenohypophysis): it is the True gland, Secretes
hormones
2) Posterior lobe (Neurohypophysis): connected to hypothalamus
through hypothalamo-hypophyseal tract, Stores hormones secreted by
hypothalamic nuclei
BLOOD SUPPLY OF PITUITARY GLAND
ARTERIES: Superior & inferior hypophyseal arteries (branches
of internal carotid artery)
VEINS: Hypophyseal veins drain into Cavernous Sinuses.
a hypothalamohypophseal
portal vessel
Superior hypophyseal: 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: supplies posterior lobe of pituitary gland.
ANTERIOR LOBE
Hormone-releasing
&
inhibiting factors
produced by
hypothalamus use
Hypophyseal Portal
System of vessels to
reach the Anterior
lobe of pituitary gland
POSTERIOR LOBE
The
neurohypophysis
receives a nerve supply from
some of the hypothalamic
nuclei (supraoptic &
paraventricular)
The axons of these nuclei
convey their neurosecretion
to the Posterior lobe of
pituitary gland through
Hypothalamo-Hypophyseal
tract from where it passes into
the blood stream.
 The
gland is composed of two parts:
Anterior lobe (adeno hypophysis)
Posterior lobe (neuro hypophysis)
 Normal
size:
Weight: 0.5g
Height: 4-12 mm
Anterior posterior: 5-16 mm
Hormonal
dysfunction
 Cushing syndrome
 Growth abnormalities e.g. Growth
hormone deficiency, acromegaly
Visual
abnormalities
headache
What
is best modality to image
the pituitary gland ?
A.
B.
C.
D.
E.
X ray
CT scan
MRI
US
Nuclear medicine
What
is 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
4
3
1- pituitary
gland
2- sphenoid
sinus
3- optic chiasm
4hypothalamus
5- pituitary stalk
6- claivus
5
2
6
1
NORMAL
PITUITARY
ADENOMA
3
2
1
4
5
6
3
2
1
4
5
6
Optic
chiasm
Pituitary
stalk
Carotid
artery
Cavernou
s sinus
Pituitary
gland
Sphenoid
sinus