2. Thorax II

Question 1

What are Pleural Membranes?

Answer 1

Fine Serous Membrane that lines the Thoracic Cavity and envelops the Lungs.

Question 2

What is a Serous Membrane?

Answer 2

Any of the Smooth, Moist, Delicate membranes

That line the closed cavities of the body and secrete a Watery Exudate.

Question 3

What are the two layers of Pleura around the Lungs?

Answer 3

1. Parietal Pleura

2. Visceral Pleura

Question 4

What is the Pleural Cavity?

Answer 4

The Pleural Cavity is normally a potential enclosed space,
Between the Parietal and Visceral Layers of Pleura,
Kept moist by a small volume of Pleural Fluid.
It is at Sub - Atmospheric pressure.

Question 5

How many Pleural Cavities are there in the Thoracic Cavity?

Answer 5

There are two Pleural Cavities within the Thoracic Cavity,

Each quite separate and containing no structures.

Question 6

What does the Parietal Pleura cover?

Answer 6

The Parietal Pleura is attached to the Chest Wall,

And covers the inside of the Thorax, Mediastinum, and Diaphragm.

Question 7

What is the Cervical Pleura?

Answer 7

The Parietal Pleura extends beyond the apex of the Lung and into the neck.
This is a region of Parietal Pleura known as Cervical Pleura.

Question 8

How is the Parietal Pleura split into regions?

Answer 8

Parietal Pleura is a Continuous Membrane,

But different areas of it receive different names based on their relationship to parts of the Thoracic Cavity.

Question 9

What are the 4 regions of the Parietal Pleura?

Answer 9

1. Costal
2. Diaphragmatic
3. Cervical
4. Mediastinal

Question 10

What is the Innervation of the Parietal Pleura?

Answer 10

The Parietal Pleura is innervated by the Intercostal and the Phrenic Nerves.

Question 11

Why might a stab wound in the neck lead to a Collapsed Lung?

Answer 11

Because the stab may clip the cervical part of the Parietal Pleura,
Damaging it and causing air to accumulate in the Pleural Space between the Lung and the chest wall.
This causes the pressure at the Pleural Space to be higher than the pressure in the Lungs,
Leading to a collapsed Lung/Pneumothorax

Question 12

What does the Visceral Pleura cover?

Answer 12

The Visceral Pleura covers the surface of the Lungs.

Question 13

What is the Visceral Pleura attached to?

Answer 13

The Visceral Pleura is attached firmly to the Lungs.

It is continuous with the Mediastinal Pleura at the root of the Lung.

Question 14

What is the Innervation of the Visceral Pleura?

Answer 14

The Visceral Pleura is innervated by the Autonomic Nervous System.

Question 15

What is the Pulmonary Ligament?

Answer 15

Not a real Ligament but a Fold of Pleural Membrane
Attaching the Lung medially to the Mediastinum.
Lies inferior to the root of the lung

Question 16

What are the 2 Pleural Recesses?

Answer 16

1. Costo - Diaphragmatic Recess

2. Costo - Mediastinal Recess

Question 17

What are the 4 Surfaces of the Lungs?

Answer 17

1. Costal
2. Vertebral
3. Diaphragmatic
4. Cardiac

Question 18

What are the other major features of the Lungs?

Answer 18

Cardiac Notch

Lingula

Question 19

What is the Apex of the Lung?

Answer 19

The blunt Superior End of the Lung.
It projects Upwards,
Above the level of the 1st Rib and into the Floor of the Neck.

Question 20

What is the Base of the Lung?

Answer 20

The Inferior Surface of the Lung,

Which sits on the Diaphragm

Question 21

Which Lung is larger?

Answer 21

The Right Lung is larger than the Left.

The Left Lung is smaller because of the space taken up by the Heart.

Question 22

What is the Cardiac Notch?

Answer 22

The Lateral Deflection of the Anterior Border of the Left Lung.
It is produced to accommodate the space taken up by the Heart.

Question 23

Which Lung has a Lingula?

Answer 23

The Left Lung has a Lingula

Question 24

What are Lobes and how many does each Lung have?

Answer 24

Each Lung is separated into Lobes branching off the main Bronchus:

• The Right Lung has Three Lobes.
• The Left Lung has only Two Lobes.

Question 25

Where is the Oblique Fissure found?

Answer 25

On Left and Right Lung.

Oblique Fissure is at the level of Rib 6.

Question 26

Where is the Horizontal/Transverse Fissure found?

Answer 26

On the Right Lung only.

Horizontal/Transverse Fissure is below the level of Rib 6.

Question 27

How many Lobes and Fissures are on the Right Lung?

Answer 27

3 Lobes

2 Fissures

Question 28

How many Lobes and Fissures are on the Left Lung?

Answer 28

2 Lobes

1 Fissure

Question 29

Which structures form impressions on the Right Lung?

Answer 29

Superior Vena Cava

Arch of Azygos Vein

Question 30

Which structures form impressions are formed on the Left Lung?

Answer 30

Arch of the Aorta
Left Common Carotid
Subclavian Arteries

Question 31

What are the 3 structures in the Hilum of the Left Lung?

Answer 31

1. Superior: Pulmonary Artery
2. Middle/Posterior: Bronchus
3. Inferior/Anterior: Pulmonary Vein

Question 32

What are the 3 structures in the Hilum of the Right Lung?

Answer 32

1. Superior/Posterior: Bronchus
2. Middle/Anterior: Pulmonary Artery
3. Inferior: Pulmonary Vein

Question 33

How can the Hilum structures be differentiated?

Answer 33

Bronchi contain Hard Cartilage,

While Artery Walls are Thicker and Stronger than Veins.

Question 34

What is the route of the right phrenic nerve?

Answer 34

Lateral to brachiocephalic artery and SVC.

Anterior to lung root.

Question 35

What is the route of the left phrenic nerve?

Answer 35

Lateral to the left subclavian artery. Crosses over vagus nerve and is anterior to lung root.

Question 36

What is the transverse pericardial sinus and what is it’s significance?

Answer 36

Pericardial cavity behind the aorta and pulmonary trunk.

Can be used to clamp the aorta and pulmonary trunk to divert or stop circulation to these arteries during cardiac surgery

Question 37

What is pericarditis and how is it related to cardiac tamponade?

Answer 37

Pericarditis is inflammation of pericardium (hence the “itis” suffix)

Causes chest pain and certain inflammatory diseases cause pericardial effusion where fluid escapes from pericardial capillaries into the pericardial cavity

If large volumes of pericardial effusion accumulate prevents heart from expanding fully, limiting inflow to the ventricles

This compression of the heart as a result of effusion into the pericardial cavity = cardiac tamponade

Can be lethal because fibrous pericardium is tough and cannot expand.

This cardiac tamponade reduces cardiac output and circulation of blood.

Question 38

How is cardiac tamponade treated?

Answer 38

Pericardiocentesis: needle and long thin tube (catheter) are used to remove the fluid