Transcript 1- Mediastinum

MEDIASTINUM
Dr. Sama ul Haque
Dr Rania Gabr
OBJECTIVES
Define
Enlist
mediastinum.
the divisions of mediastinum.
Describe
the boundaries and
contents of mediastinum.
LATERAL VIEW OF THORAX
MEDIASTINUM
Definition:
A median septum or median
partition between the two pleural
cavities.
It includes all the structures
which lie in the intermediate
compartments of the thoracic
cavity
Boundaries of the Mediastinum
Superior boundary:
Superior thoracic aperture
Inferior boundary:
Diaphragm
Anterior boundary:
Sternum
Posterior boundary:
Bodies of vertebrae T1 to T12
Lateral boundaries:
Mediastinal parietal pleura
(left and right).
Divisions of Mediastinum
1. Superior mediastinum:
Above the imaginary plane between the
sternal angle and the lower border of the 4th
thoracic vertebra.
Divisions of Mediastinum
2. Inferior mediastinum:
Below the imaginary plane and it is further
subdivided into:
a. Anterior mediastinum: Behind the body and
xiphoid process of the sternum and in front of
the middle mediastinum (pericardium).
b. Middle mediastinum: Contains pericardium,
heart and the roots of the great vessels.
c. Posterior mediastinum: lies behind the middle
mediastinum (the part that lies posterior to the
pericardium and anterior to the bodies of
vertebrae T5 to T12).
MEDIASTINUM
DIVISIONS OF MEDIASTINUM
CONTENTS OF THE SUPERIOR MEDIASTINUM
From post. to ant.:
• Esophagus
• Trachea
• Arch of Aorta: and its 3 brs:
1- Brachiocephalic artery
2- Left common carotid artery
3- Left subclavian artery
• Brachiocephalic veins
• Superior vena cava
• Remains of Thymus
Nerves:
• Phrenic nerves: rt and lt
• Vagus nerves: rt and lt
• Left recurrent laryngeal nerve
• Sympathetic trunk
Others
• Lymph nodes and Thoracic duct
SUPERIOR MEDIASTINUM
SUPERIOR MEDIASTINUM
INFERIOR MEDIASTINUM
INFERIOR MEDIASTINUM
INFERIOR MEDIASTINUM (LATERAL VIEW)
ANTERIOR MEDIASTINUM
• Sternopericardial
ligaments
• Lymph nodes
• Remains of
thymus
MIDDLE MEDIASTINUM (LATERAL VIEW)
• Pericardium
• Heart
• Arteries: Roots of the
great vessels: aorta
and pulmonary art.
• Veins: lower half of
superior vena cava,
terminations of
inferior vena cava &
pulmonary veins
• Nerves: Phrenic
nerves
• Bifurcation of trachea
• Lymph nodes
POSTERIOR MEDIASTINUM
• Descending thoracic
Aorta
• Esophagus: most anterior
• Thoracic duct
• Azygous vein
• Hemiazygous vein
• Vagus nerves
• Rt and lt Sympathetic
trunks and their brs:
splanchnic nerves
• Lymph nodes
POSTERIOR MEDIASTINUM
POSTERIOR MEDIASTINUM
POSTERIOR MEDIASTINUM
POSTERIOR MEDIASTINUM
POSITIONAL CHANGES OF MEDIASTINUM