Thoracic Wall Anatomy

Question 1

Name the three compartments of the thoracic cavity.

Answer 1

1) Left Pleural Cavity

2) Right Pleural Cavity

3) Mediastinum

Question 2

List some functions of the thoracic cavity.

Answer 2

Breathing, Organ Protection, Organ Conduit

Question 3

What is the name of the top opening of the thorax?

Answer 3

Superior Thoracic Aperture

Question 4

What is the name of the bottom opening of the thorax?

Answer 4

Inferior Thoracic Aperture

Question 5

What is the most important function of the intercostal muscles?

Answer 5

Maintain tone in intercostal space

Question 6

Which muscles are most active during inspiration and help ribs move superiorly?

Answer 6

External Intercostal Muscles

Question 7

Which muscles are most active during expiration and help ribs move inferiorly?

Answer 7

Internal Intercostal Muscles; Innermost Intercostal Muscles

Question 8

What are the boundaries of the mediastinum?

Answer 8

Superior thoracic aperture on top

Diaphragm on bottom

Sternum anteriorly

Thoracic vertebrae posteriorly

Pleural cavities laterally

Question 9

Identify the structural (skeletal) elements of the thoracic wall.

Answer 9

Twelve Thoracic Vertebrae

Twelve pairs of ribs

Sternum

Question 10

Define boundaries for the superior thoracic aperture.

Answer 10

T1 vertebra posteriorly

Medial margins of 1st rib laterally

Manubrium of sternum anteriorly

Question 11

Define boundaries for the inferior thoracic aperture.

Answer 11

T12 vertebra posteriorly

11th and 12th ribs posteriolaterally

Cartilage of ribs 7-10 anteriolaterally

Xiphoid process anteriorly

Question 12

What is the source of arterial blood supply to the breast?

Answer 12

Branches of Lateral Thoracic Artery, Internal Thoracic Artery, and Anterior/Posterior Intercostal Arteries

Question 13

Posterior Intercostal veins drain into which system?

Answer 13

Azygos

Question 14

Anterior intercostal veins drain into which system?

Answer 14

Internal Thoracic Veins

Question 15

What is it called when you insert a needle through the thorax to withdraw a fluid sample?

Answer 15

Thoracocentesis

Question 16

What is the main source of bloodflow to the thoracic wall?

Answer 16

Anterior and Posterior Intercostal Arteries

Question 17

List the layers of the thoracic wall from External to Internal.

Answer 17

Skin

Superficial Fascia

External Intercostal Muscle

Internal Intercostal Muscle

Intercostal Vein, Artery, and Nerve

Innermost Intercostal Muscle

Endothoracic Fascia

Parietal Pleura

Pleural Space

Visceral Pleura

Lung

Question 18

Label this

Answer 18

Question 19

Label this

Answer 19

Question 20

Label this

Answer 20

Question 21

Label this

Answer 21

Question 22

Describe lymphatic drainage of the anterior thoracic wall

Answer 22

**Anterior Thoracic Wall **to

**Parasternal Nodes **to

**R and L Bronchomediastinal Trunks **to

RIght Lymphatic Duct (from R Bronchomediastinal Trunk)

and

Thoracic Duct ( from L Bronchomediastinal Trunk)

Question 23

Describe lymphatic drainage of the posterior thoracic wall

Answer 23

Posterior Thoracic Wall to

Intercostal Nodes

Directly into **Thoracic Duct **

OR

Indirectly via Bronchomediastinal Trunks.

Question 24

What innervates the thoracic wall?

Answer 24

12 pairs of thoracic ventral rami

11 intercostal nerves

1 subcostal nerve