Pleura and Lungs

Question 1

What are the boundaries of the thoracic inlet?

Answer 1

The manubrium, rib 1 (+ its costal cartilage), and the body of vertebra T1.

Question 2

What are the boundaries of the thoracic outlet?

Answer 2

The body of T12, the costal margin and the xiphisternal joint.

Question 3

What is the suprapleural membrane?

Answer 3

A dome-shaped thickening of the endothoracic fascia over the thoracic inlet occupied by the cupola of each lung.

Question 4

What serous membrane lines each thoracic cavity?

Answer 4

The pleural membrane (parietal pleura).

Question 5

What are the various divisions of the parietal pleura?

Answer 5

Costal, mediastinal, diaphragmatic and cervical pleura.

Question 6

How does parietal pleura differ from visceral with regard to innervation?

Answer 6

Parietal pleura is highly innervated, visceral pleura is not innervated.

Question 7

Where does parietal pleura become visceral pleura?

Answer 7

Where it reflects off the mediastinum (as the mediastinal division of parietal pleura) onto the surface of the lung at the root of the lung.

Question 8

What is the pulmonary ligament?

Answer 8

A cuff-like extension of this reflection of parietal/visceral pleura at the root of the lung inferiorly along the mediastinum.

Question 9

What attaches the costal pleura to the back of the thoracic cage?

Answer 9

Endothoracic fascia.

Question 10

What is a pleural recess?

Answer 10

A reflection of parietal pleura off one aspect of the body wall onto another forming a thin slit-like serous lined region into which the sharp borders of the lung rarely insert - even during deep inspiration.

Question 11

What is the function of the pleural recesses?

Answer 11

A region for expansion of the lung duyng deep inspiration.

Question 12

Name two pleural recesses.

Answer 12

Costodiaphragmatic and costomediastinal.

Question 13

Which specific aspect of the lung would insert into each recess?

Answer 13

The sharp anterior border of the lung slips into the costomediastinal recess; the sharp inferior border of the lung inserts down into the costodiaphragmatic recess.

Question 14

Cite a clinical implication of these recesses.

Answer 14

Fluid accumulates in these regions (specifically the costodiaphragmatic) in pathological conditions. It is generally removed from these regions by thoracocentresis so that the lung is not pierced by the needle withdrawing the fluid.

Question 15

What is meant by negative pressure of the thoracic cavity?

Answer 15

It keeps the moist visceral pleura of the lung adherent to the moist parietal pleura of the thoracic wall. Movement of the wall pulls the lung with it - inspiration and expiration.

Question 16

What causes the visceral pleura to adhere to the parietal pleura?

Answer 16

A thin layer of pleural fluid and the negative pressure.

Question 17

What is a pneumothorax?

Answer 17

Air enters the pleural cavity causing the two pleural layers to separate (and the lung to collapse).

Question 18

What is a hemothorax?

Answer 18

Blood enters the pleural cavity and forces the two pleural layers apart.

Question 19

Which aspect of the thorax would you apply the stethoscope to in order to listen to the airways in the upper lobe of each lung?

Answer 19

To listen to the airway sounds in the upper lobe of either lung, you would place the stethescope on the anterior thoracic wall.

Question 20

Which aspect of the thorax would you apply the stethoscope to in order to listen to the airways in the lower lobe of each lung?

Answer 20

On the posterior thoracic wall.

Question 21

Which aspect of the thorax would you apply the stethoscope to in order to listen to the airways in the apical region?

Answer 21

In the lateral thoracic inlet.

Question 22

Which aspect of the thorax would you apply the stethoscope to in order to listen to the airways in the middle lobe of the right lung?

Answer 22

On the lateral thoracic wall.

Question 23

What vessels supply lung tissue with oxygenated blood?

Answer 23

The bronchial aa.

Question 24

From where do the vessels that supply lung tissue arise?

Answer 24

Off the aorta

Question 25

What is the relationship between bronchi and pulmonary aa.?

Answer 25

The pulmonary aa. follow the bronchial tree - most commonly above it.

Question 26

What is the relationship between bronchi and pulmonary vv.?

Answer 26

Pulmonary vv. lie below the bronchi at the hilus/root of the lung.

Question 27

Which main bronchus is longer and why?

Answer 27

The left is longer and more horizontal as it passes over the heart.

Question 28

Which main brochus is explored first when objects are aspirated? Why?

Answer 28

The right bronchus is always explored first with the bronchoscope. Because it is more vertical and in-line with the trachea so objects tend to enter it rather than the more horizontal left main bronchus.

Question 29

What does a main (primary) bronchus supply?

Answer 29

A Lung

Question 30

What does a secondary bronchus supply?

Answer 30

A lobe

Question 31

What does a tertiary bronchus supply

Answer 31

A bronchopulmonary segment (BPS)

Question 32

What is a bronchopulmonary segment?

Answer 32

The smallest surgically resectable portion of a lung.

Question 33

How many BPS’s are found in each lung?

Answer 33

There are 10 BPS in each lung.

Question 34

What is the clinical implication of BPS’s?

Answer 34

They are the smallest surgically resectable portion of a lung as well as the knowledge of their position in the lung is important for positioning the patient for postural drainage.

Question 35

What clinical implication does the autonomic innervation of the lungs have?

Answer 35

The parasympathetic innervation (vagus nerve) constricts the smooth muscle in the walls of the bronchioles - asthma (highly atypical as the sympathetic division normally constricts smooth muscle).

Question 36

To what nodes do the superficial and deep lymphatics of the lung drain?

Answer 36

The bronchopulmonary nodes.

Question 37

Where are the bronchopulmonary nodes located?

Answer 37

At the root of the lung.

Question 38

From here the lymph passes to what other groups located along the bronchus and
trachea?

Answer 38

To the tracheobronchial and paratracheal nodes respectively.