Anatomy of the Thoracic Cavity

Question 2

What is a Body Cavity?

Answer 2

An area of the body which confines organs and systems with related functions. Lined by serous membranes.

Question 3

What makes up the Thoracic Cavity?

Answer 3

Lungs and Chest Wall - Lined with Pleura
Heart - Covered by Pericardium

Question 4

What lines the Abdominal and Pelvic Cavities?

Answer 4

Peritoneum

Question 5

How is the Thoracic Cavity divided?

Answer 5

Divided into two independant pleural cavities and the mediastinum between them

Question 6

Where are the attachments of the Parietal Pleura?

Answer 6

• Thorax wall (Costal Pleura)
• Fascia at Thoracic Inlet (T1 and Rib 1)
• Fibrous Pericardium (Mediastinal Pleura)
• Diaphragm (Diaphragmatic Pleura)

Question 7

What are the two Pleural Surfaces?

Answer 7

Visceral - closest to the organ
Parietal - closest to the outside of the body

Question 8

What is the Mediastinum?

Answer 8

Space found between the pleural sacs, sternum, costal cartilages, thoracic vertebrae and the diaphragm. It is highly mobile and allows for changes in volume and pressure.

Question 9

Describe the location of the Superior Mediastinum

Answer 9

Between the thoracic inlet and the plane of the sternal angle (T4/T5 disc)

Question 10

Describe the location of the Inferior Mediastinum

Answer 10

Between the plane of the Sternal Angle (T4/T5 disc) and the Diaphragm

Question 11

What structures are found to the right of the Mediastinum?

Answer 11

Structures related to the right atrium and veins:
* Superior Vena Cava
* Arch of the Azygos Vein
* Inferior Vena Cava

Question 12

What structures are found to the left of the Mediastinum?

Answer 12

Structures related to the left ventricle and arteries:
* Left Common Carotid Artery
* Left Subclavian Artery
* Arch of Aorta
* Thoracic Aorta

Question 13

What is found in the Middle Mediastinum?

Answer 13

• Pericardium
• Heart
• Origins of Aorta and Pulmonary Trunk
• Terminal points of Superior and Inferior Vena Cava
• Some smaller blood vessels (pulmonary veins)
• Phrenic Nerves
• Branches of Vagus

Question 14

Describe the Structure of the Pericardium

Answer 14

Fibro-serous sac that encloses Heart and roots of the Great Vessels

Question 15

What is the Function of the Pericardium?

Answer 15

• Anchors the heart in place without compromising cardiac movement
• Prevents overexpansion of the heart

Question 16

What are the layers of Pericardium?

Answer 16

• Fibrous (external)
• Serous (internal)

Question 17

Describe the attachments of the Fibrous Pericardium

Answer 17

• Adventitia of the Great Vessels
• Sternum and Costal Cartilage 3-6 (sterno-pericardial ligament)
• T5-T8 vertebrae (pericardiovertebral ligaments)
• Diaphragm (Pericardiophrenic ligament)

Question 18

What are the layers of the Serous Pericardium?

Answer 18

• Parietal Layer
• Visceral Layer

Question 19

Describe the location of the Parietal Layer of the Serous Pericardium

Answer 19

Lines the inner aspect of the fibrous pericardium

Question 20

Describe the Visceral Layer of the Serous Pericardium

Answer 20

Same as the epicardium

Question 21

Where is the Pericardial Cavity?

Answer 21

Between the Parietal and Visceral Layers of Serous Pericardium

Question 22

Describe the Pericaridal Fluid

Answer 22

• Produced by Serous Pericardium
• Reduces Friction during contraction of heart
• Typically 10-15ml

Question 23

Describe the location of the Transverse Pericardial Sinus

Answer 23

• Posterior to the Ascending Aorta and Pulmonary Trunk
• Anterior to the Superior Vena Cava

Question 24

Describe the location of the Oblique Pericardial Sinus

Answer 24

Surrounded by the reflection of the Serous Pericardium around the right and left Pulmonary Veins and Inferior Vena Cava

Pink Arrow

Question 25

What does the phrenic nerve innervate?

Answer 25

Motor supply to: * Diaphragm Sensory supply to: * Mediastinal Parietal Pleura * Peritoneum * Parietal Pericardium * Pleura related to the central tendon of the diaphragm

Question 26

Where would you feel Phrenic Refered Pain?

Answer 26

* Back of Neck * Supraclavicular Region * Shoulder Tip

Question 27

Describe the location of the Anterior Mediastinum

Answer 27

Bounded by sternum and xiphisternum, pericardium and lungs with pleura. Prevascular compartment.

Question 28

What Structures are found within the Anterior Mediastinum?

Answer 28

* Thymus * Internal Thoracic Vessels * Lymph Nodes * Connective Tissue * Fat Tissue * Lower pole of Thyroid

Question 29

Describe the location of the Thymus Gland

Answer 29

Between the Manubrium and Sternum and the Pericardium. Extends from Jugular Notch to 4th Costal Cartilage.

Question 30

Describe the Structure of the Thymus Gland

Answer 30

Bi-lobed organ of Lymphoid Tissue active in childhood until puberty. Increasing fibro-fatty infiltration with age Related to: * Pericardium * Superior Vena Cava * Aorta * Left and Right Brachiocephalic Veins * Pleura * Phrenic Nerves * Trachea