Overview of the Thorax

Question 1

What is the thoracic wall made up of?

Answer 1

It is made of 12 thoracic vertebrae

Question 2

How many true ribs are there? False ribs?

Answer 2

There are 7 true ribs and 3 false ribs. There are also 2 floating ribs.

Question 3

What are false ribs?

Answer 3

Ribs that are indirectly attached to the sternum

Question 4

What are the parts of the sternum?

Answer 4

Manubrium
Body
Xiphoid Process

Question 5

What is the sternal angle?

Answer 5

The articulation between the manubrium and the body of the sternum

Question 6

What is the sternal angle also known as?

Answer 6

Angle of Louis

Question 7

At what vertebrae approximately is the sternal angle located?

Answer 7

T4-T5

It is located around the second pair of ribs.

Question 8

What are the 3 layers of the intercostal muscles?

Answer 8

External Intercostal
Internal Intercostal
Innermost Intercostal

Question 9

What is the blood supply of the anterior thoracic wall?

Answer 9

Anterior Intercostals 
(branches of the internal thoracic and musculophrenic arteries)

Superior Thoracic Artery
(branch of the axillary artery)

Question 10

What is the blood supply of the posterior thoracic wall?

Answer 10

Posterior Intercostals

branches of the aorta and costocervical trunk

Question 11

What is the innervation of the intercostal muscles?

Answer 11

Ventral Rami of the Thoracic Nerves (intercostal nerves)

Question 12

In the intercostal spaces, describe the order of the nerves, arteries and veins, superior to inferior.

Answer 12

Veins
Arteries
Nerves

VAN - important to avoid hitting the nerve

Question 13

What are the major compartments of the thorax?

Answer 13

Two lungs and the mediastinum (space between the pleural cavity)

Question 14

What is the jugular notch? What level does it sit at?

Answer 14

It is the superior border of the manubrium. It sits at around the level of T2.

Question 15

Which thoracic vertebrae lie above the manubrium?

Answer 15

T1 and T2

Question 16

About what level does the xiphoid process sit at?

Answer 16

T9-T10

Question 17

What are the three cavities that are formed embryologically and their functions?

Answer 17

Pleural - house the lungs
Pericardial - house the heart
Peritoneal - house all the abdominal structures

Question 18

What is the general function of the cavities of the thorax?

Answer 18

Provide lubrication for the moving structures

Question 19

What is an important concept of the cavities in the thorax?

Answer 19

The visceral and parietal layers are continuous where the organ has punched the tissue in

Question 20

Describe the venous drainage of the superior mediastinum.

Answer 20

It goes from the right internal jugular the right subclavian to the right brachiocephalic into the superior vena cava.

Question 21

How is venous drainage from the left different from on the right?

Answer 21

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

Question 22

At about what level does the trachea divide?

Answer 22

Sternal Angle (T4-T5)

Question 23

How does the vagus nerve enter the abdominal cavity?

Answer 23

It rides along with the esophagus

Question 24

What are the contents of the superior mediastinum?

Answer 24

Aortic Arch
Brachiocephalic Trunk
Brachiocephalic Vein
Left Common Carotid Artery
Left Subclavian Artery
Superior Vena Cava
Vagus Nerve
Phrenic Nerve

Question 25

What are the contents of the middle mediastinum?

Answer 25

Pericardium
Heart
Phrenic Nerves

Question 26

What are the contents of the anterior mediastinum?

Answer 26

Areolar Tissue

Lymph Nodes

Question 27

What are the contents of the posterior mediastinum?

Answer 27

Descending Aorta
Esophagus
Vagus Nerve
Thoracic Splanchnic Nerve
Thoracic Duct

Question 28

What are the pleural cavities?

Answer 28

The pleural cavities are closed sacs that invest each lung and contain serous fluid for lubrication during respiration.