Anatomy of the Pleura and Diaphragm

Question 1

The pleural space normally contains a small amount of fluid that reduces friction during breathing. How many mL of fluid?

Answer 1

<5 mL

Question 2

The “intercostal stripe” represents what?

Answer 2

The combination of two pleural layers, the endothoracic fascia, and innermost intercostal muscle

Question 3

Presence of soft tissue density between the inner rib and the lung, best appreciated on HRCT studies, indicates what disease?

Answer 3

Pleural thickening

Question 4

The innermost intercostal muscle is anatomically absent in the paracerterbral area, and if a thin line is visible between the lung and paravertebral fat or rib, it represents what?

Answer 4

Represents a combination of two pleural surfaces and the endothoracic fascia

Question 5

Where does the diaphragmatic muscle arise?

Answer 5

It arises anteriorly from the posterior aspect of the xiphoid process and anterolateraly, laterally, and posterolaterally from the sixth to the twelfth costal cartilages and ribs

Question 6

Where does the diaphragmatic crura originate?

Answer 6

It originates from the upper lumbar vertebrae and course to the posterior aspect of the central tendon

They have no direct action on the rib cage

Question 7

The diaphragm has how any openings and potential gaps?

Answer 7

Three normal openings and two potential gaps

Question 8

What hiatus lies midline, immediatelty behind the diaphragmatic crura and anterior to the twelfth thoracic vertebral body?

Answer 8

Aortic hiatus

Question 9

What are the structures that traverse the aortic hiatus?

Answer 9

Aorta, thoracic duct, and azygos and hemiazygos veins

Question 10

What hiatus lies slightly to the left of midline, cephalad to the aortic hiatus, and transmits the esophagus and vague nerves?

Answer 10

Esophageal hiatus

Question 11

The inferior vena cava pierces the central tendon of the diaphragm at what level?

Answer 11

At the level of the eight thoracic intervertebral disk space

Question 12

These are triangular gaps in the muscles of the anteromedial diaphragm.

Answer 12

Foramina of Morgagni

This cleft is normally occupied by fat and the internal mammary vessel

It is a site of potential intrathoracic herniation of abdominal contents

Question 13

This foramina are defects in the closure of the posterolateral diaphragm at the junction of the pleuroperitoneal membrane with the transverse septum

Answer 13

Foramina of Bochdalek

Question 14

The inferior aspects of the diaphragmatic crura may have a rounded appearance in cross section and should not be mistaken for what?

Answer 14

Enlarged retrocrural lymph nodes