Transcript Mediastinum & peicardium

the Cardiovascular System
“Mediastinum”
By:
Dr. Nabil A Khouri MD, MsC, Ph.D
Bony Thorax (Thoracic Cage)
General Structure of thoracic Vertebrae
Thoracic Vertebrae
Mediastinum
• Is the middle compartment of the thoracic cavity which is
situated between the right and left mediastinal surface of
the lungs covered by pleura.
• Boundaries:
– Anteriorly, the sternum and the costal cartilages.
– Posteriorly, the bodies of 4-12 thoracic vertebrae.
– Superiorly, the thoracic inlet.
– Inferiorly, the diaphragm.
– Laterally (on each side), the mediastinal pleura
First rib “Thoracic inlet”
MEDIASTINUM
Inferior mediastium
Superior boundaries:
Sternal Angle to T4/5
(Inter VD)
Inferior boundaries:
Middle of Xiphoid process
to T9
Diaphragm
IX
2
3
4
5
6
7
8 9 Body
The Location of the Heart within the
medastinum
The superior mediastinum
Located above the heart and
therefore lying behind the
manubrium sterni contains:
the great vessels of the
heart
Level of Manb. Sterni
Contents of sup. mediastinum
•
The arch of the aorta with its three large branches.
•
Right and left brachiocephalic veins.
•
The upper part of the superior vena cava.
•
The vagus (10th cranial), the phrenic and the left recurrent laryngeal
nerves.
•
The thymus (in children, or some possible remnants in adults).
•
The trachea.
•
The esophagus.
•
Some lymph nodes.
A transverse section of the thorax, showing the
contents of the Anterior, middle and the
posterior mediastinum
Posterior
Mediastiunum
Content
of the posterior mediastinum
• artery
– thoracic part of the descending aorta
• veins
– azygos vein
– the hemiazygos vein and the accessory hemiazygos vein
• nerves
– vagus nerve
– splanchnic nerves (but not the sympathetic chain[1])
• esophagus
• thoracic duct
• some lymph glands
Posterior Right side mediastinum
Sympathetic plexus
SVC
Br. Ceph. Vein
Intercostal arteries and veins
Azygos Vein
Rt. Prim. Bronch.
Lymph Nods
Pulmonary Arteris
Pulmonary Veins
Esophagus
Rt. Vagus N
Rt Phrenic N
Left Side
Thoracic Cavity
1 2 3
Aorta
4 – Brachio-Ceph. Trunk
5 - Descending Aorta
6 - Left. Main Bronch.
7 - Pulmonary V
8 - Phrinic N and
Pericardio-phrenic A
Right
Left
Fluid level in Esophagus
Anterior mediastinal nodes Lymphoma
The Pericardium
• Outer sac – Fibrous
• Inner - Serous, is a double layered sac –(parietal and
visceral pericardium
• Between the parietal and visceral pericardium is a Small
space – the pericardial Cavity
• It is filled with pericardial fluid (lubricates and reduces
friction between the two surfaces).
• The most inner of these two serous layers actually forms
the Epicardium and is in direct contact with myocardium
The Pericardium
Filled with Pericardial Fluid
Pericardio-phrenic
Ligament
Central tendon of the diaphragm
Superior Vena
Cava
Aorta
Pulmonary
trunk
Right
Left
Pulmonary
Arteries
Inferior Vena
Cava
Pericardial sinuses
Pericardial Sinuses
• Two In number:
– Lies within the pericardial cavity, at the points where the visceral
and parietal pericardia are continuous with one another.
– The pericardial sinuses are:
• transverse pericardial sinus (Open “Connected Lt-Rt”)
– Between the reflections of pericardium onto the aorta
and pulmonary trunk superiorly and the pulmonary
veins inferiorly
• oblique pericardial sinus (closed “Not continuous”)
– The cul-de-sac enclosed located between the limbs
of the U lies behind the left atrium and is known as
the oblique sinus,
– It is a recess in the pericardial cavity posterior to the
base of the heart bounded laterally by the pericardial
reflections on the pulmonary veins and inferior vena
cava, and posteriorly by the pericardium overlying
the anterior aspect of the oesophagus.
THE Pericardial
reflection
Right side view
Oblique
Sinus
Innervations
• The fibrous pericardium and the parietal layer of
the serous pericardium are sensory innervated
by the phrenic nerves (C3-C5).
• The epicardium receives autonomic innervation
from the underlying heart.
• Excessive accumulation of fluid in the pericardial
cavity and may lead to the compression of the
heart.
– Restriction of the heart movement may lead to
cardiac arrest.
Pericardium Relation
The Heart Wall