Thoracic Cavity & Mediastinum
Upon completion of this session, the student will be able to:
1. To study the thoracic cage, which is formed by the sternum, the ribs and the thoracic vertebrae.
2. To study the thoracic cavity, and define its contents.
3. To understand the concept of the mediastinum, and define its divisions & their contents.
4. To study the great vessels and to learn their relationships to each other and to the other structures in
the superior mediastinum.
5. Defiine the pericardial cavity
of Dissection Procedure
a. Identify on a skeleton and where possible on the cadaver,
|a. Review the sternum and its three parts.
b. Study the 12 ribs.
| a. Internal thoracic (mammary) artery
a. musculophrenic artery
b. superior epigastric artery
b. intercostal arteries and veins
a. anterior - from where?
b. posterior - from where?
What is the relationship of the intercostal veins to the azygos vein?
c. intercostal nerves - 12 pairs
a. T1 to T11 are intercostal
b. T12 is subcostal
What is the relationship of an intercostal vein, artery, and nerve?
| a. superior and inferior thoracic apertures
1. two pleural sacs, each enclosing a lung
2. the mediastinum
| a. Subdivisions How
are the subdivisions of the mediastinum structured?
b. anterior and posterior
c. middle - content?
b. Superior Mediastinum
|a. The pericardium surrounds the heart and proximal portion of the great
This fibroserous sac is composed of two layers:
(1) parietal pericardium
a. an outer fibrous layer
b. an inner serous layer
(2) visceral pericardium
a. reflected onto the heart and great vessels
b. Pericardial reflections
(1) the oblique sinus - posterior to the heart
(2) the transverse sinus - posterior to the ascending aorta and pulmonary trunk
c. Arteries of the pericardium
(1) pericardiophrenic From where does this artery arise?
(2) musculophrenic branches to the base of the heart
What is pericarditis? Cardiac tamponade?