Transcript Thyroid, Parathyroid and Suprarenal Glands

THYROID, PARATHYROID
AND SUPRARENAL
GLANDS
Dr Rania Gabr
OBJECTIVES
 By
the end of the lecture, the student
should be able to:
Describe the shape, position, relations and
structure of the thyroid gland.
 List the blood supply & lymphatic drainage of the
thyroid gland.
 Describe the shape, position, blood supply &
lymphatic drainage of the parathyroid glands.
 Describe the shape, position, blood supply &
lymphatic drainage of the adenal glands.

Deep cervical
fascia of the
neck
It is divided into 3
layers:
1- Investing
layer.
2- Pretracheal
layer.
3- Prevertebral
layer.
3



Consists of right
& left lobes.
The 2 lobes are
connected to each
other by a
narrow isthmus,
which overlies
the 2nd 3rd & 4th
tracheal rings.
It is surrounded
by a sheath
derived from the
pretracheal
layer of
cervical
fascia.
Thyroid gland
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Each lobe is pear
shaped, with its apex
directed upward as for
as the oblique line of
the thyroid cartilage its
base lies at the 4th or
5th tracheal ring.
Posterior
Anterior
The isthmus
extends across
the midline in
front of the 2nd
3rd & 4th
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tracheal rings.
Inside the
pretracheal
facial capsule,
there is another
capsule.
So, it s
surrounded by
2 membranes.
A small pyramidal
lobe is often present
which projects from
the upper border
of the isthmus
usually to left of
middle line.
Pyramidal lobe is
connected to hyoid
bone by a fibrous or
muscular band
called levator
glandulae
thyroideae.
This represents the
fibrosed &
obliterated
thyroglossal duct.
Levator
glandul
ae
thyroide
ae
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RELATIONs
OF
THE
THYROID
Anterolaterally:
(4 S).
1. Sternothyroid.
2. Sternohyoid.
3. Superior belly
of omohyoid
4. Sternomastoid.
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ARTERIAL
SUPPLY

:
1-Superior thyroid artery:
From the external carotid
artery
It descends to the upper pole
of the lobe, with the
external laryngeal nerve.
It runs along the upper
border of the isthmus to
anastomosis with its
fellow.
2- Thyroidea ima artery:
If present, it arises from
aortic arch or from
brachiocephalic artery.
It ascends in front of the
trachea to reach the
isthmus.
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3-Inferior thyroid
artery
From the
thyrocervical
trunk of 1st part of
subclavian artery,
ascends behind the
gland to the level of
cricoid cartilage.
It curves medially
behind the carotid
sheath.
Then it reaches the
posterior aspect of
the gland &
descends
downwards.
The recurrent
laryngeal nerve
crosses either in
front or behind it.
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Veins of Thyroid Gland
1-Superior thyroid vein
internal jugular vein
2- Middle thyroid vein
internal jugular vein
3- Inferior thyroid veinunite
left brachiocephalic
vein
Lymph Of the
Thyroid
Gland:
Deep cervical
& paratracheal
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Nerves:
Sympathetic fibers from superior,
middle, and inferior cervical ganglia
reach the gland through the
 1- laryngeal and
 2- cardiac branches of the vagus nerve

PARATHYROID GLAND
4 small ovoid bodies, about 6
mm. long.
They lie within the fascial
capsule of the gland,
(between the 2 membranes).
2 superior parathyroid has
a constant position at the
middle of posterior border of
the gland.
2 inferior parathyroid
usually at the level of the
inferior pole.
They sometimes lie within
the thyroid tissue or
sometimes outside the
fascial capsule.
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•
•
•
•
•
•
•
•
Arterial supply
They are supplied mainly by the inferior
thyroid artery
Venous Drainage
Blood is drained mainly by inferior
thyroid vein
Lympahatic drainage
Lymph is drained to deep cervical and
paratracheal lymph nodes
Nerve Supply
They are supplied by sympathetic fibers
SUPRARENAL GLANDS



The two suprarenal glands
are yellowish retroperitoneal
organs that lie on the upper
poles of the kidneys , just
above the level of T12
They are surrounded by renal
fascia (but are separated from
the kidneys by the perirenal
fat).
Each gland has an outer
cortex and an inner
medulla.
• The right gland
is pyramidal in
shape and caps
the upper pole
of the right
kidney.
• Relations:
• Anterior:
right lobe of
the liver and
inferior vena
cava.
• Posterior:
diaphragm.
• The left gland
is crescentic in
shape and
extends along
the medial
border of the
left kidney from
the upper pole
to the hilus.
• Relations:
• Anterior:
pancreas,
lesser sac,
and stomach
• Posterior:
diaphragm.
 Arteries:
Each gland receives
branches from three
main arteries:
 1- Superior
suprarenal a. from
Inferior phrenic
 2- Middle
suprarenal art.
From the Aorta
 3- Inferior
suprarenal art.
From Renal artery.
• Veins:
• A single vein emerges
from the hilum of
each gland
• The right adrenal
vein drains into the
Inferior vena cava
• The left adrenal
vein drains into the
lt Renal vein on the
left.
• Lymph Drainage:
The lymph drains
into the lateral
aortic nodes.
• Nerve Supply:
Preganglionic
sympathetic fibers derived
from the splanchnic nerves.
Most of the nerves end in the
medulla of the gland.