Overview of the Thorax Flashcards
What is the thoracic wall made up of?
It is made of 12 thoracic vertebrae
How many true ribs are there? False ribs?
There are 7 true ribs and 3 false ribs. There are also 2 floating ribs.
What are false ribs?
Ribs that are indirectly attached to the sternum
What are the parts of the sternum?
Manubrium
Body
Xiphoid Process
What is the sternal angle?
The articulation between the manubrium and the body of the sternum
What is the sternal angle also known as?
Angle of Louis
At what vertebrae approximately is the sternal angle located?
T4-T5
It is located around the second pair of ribs.
What are the 3 layers of the intercostal muscles?
External Intercostal
Internal Intercostal
Innermost Intercostal
What is the blood supply of the anterior thoracic wall?
Anterior Intercostals (branches of the internal thoracic and musculophrenic arteries)
Superior Thoracic Artery
(branch of the axillary artery)
What is the blood supply of the posterior thoracic wall?
Posterior Intercostals
branches of the aorta and costocervical trunk
What is the innervation of the intercostal muscles?
Ventral Rami of the Thoracic Nerves (intercostal nerves)
In the intercostal spaces, describe the order of the nerves, arteries and veins, superior to inferior.
Veins
Arteries
Nerves
VAN - important to avoid hitting the nerve
What are the major compartments of the thorax?
Two lungs and the mediastinum (space between the pleural cavity)
What is the jugular notch? What level does it sit at?
It is the superior border of the manubrium. It sits at around the level of T2.
Which thoracic vertebrae lie above the manubrium?
T1 and T2
About what level does the xiphoid process sit at?
T9-T10
What are the three cavities that are formed embryologically and their functions?
Pleural - house the lungs
Pericardial - house the heart
Peritoneal - house all the abdominal structures
What is the general function of the cavities of the thorax?
Provide lubrication for the moving structures
What is an important concept of the cavities in the thorax?
The visceral and parietal layers are continuous where the organ has punched the tissue in
Describe the venous drainage of the superior mediastinum.
It goes from the right internal jugular the right subclavian to the right brachiocephalic into the superior vena cava.
How is venous drainage from the left different from on the right?
The left brachiocephalic vein must cross diagonally across the manubrium to enter the superior vena cava, and as a result, it is more elliptical in the cross section that the right brachiocephalic vein
At about what level does the trachea divide?
Sternal Angle (T4-T5)
How does the vagus nerve enter the abdominal cavity?
It rides along with the esophagus
What are the contents of the superior mediastinum?
Aortic Arch Brachiocephalic Trunk Brachiocephalic Vein Left Common Carotid Artery Left Subclavian Artery Superior Vena Cava Vagus Nerve Phrenic Nerve
