-L-03-Pleural-Cavities-Lungs

Question 1

1. Pleural Cavities

Q: What are the pleural cavities
Q: What are the two layers of the pleura?
Q: What is the pleural cuff?

Answer 1

A: Separate right and left cavities containing serous fluid to reduce friction during respiration.
A: Visceral pleura (covers lungs, smooth, not pain-sensitive) and parietal pleura (adheres to thoracic wall, pain-sensitive
A: The junction between visceral and parietal pleura, surrounding the hilum and forming the pulmonary ligament.

Question 2

2. Parietal Pleura

Q: What are the four parts of the parietal pleura
Q: What innervates the parietal pleura?

Answer 2

A: Cervical, costal, mediastinal, diaphragmatic
A: - Cervical & costal: Intercostal nerves
* Mediastinal & central diaphragmatic: Phrenic nerve
* Peripheral diaphragmatic: Lower 5 intercostal nerves.

Question 3

3. Clinical Conditions

Q: What is pneumothorax?
Q: What is pleural effusion?
Q: What is hemothorax?

Answer 3

A: Air in the pleural cavity, causing lung collapse.
A: Excess fluid in the pleural cavity, restricting lung expansion
A: Accumulation of blood in the pleural cavity.

Question 4

4. Lungs

Q: What are the differences between the right and left lungs?
Q: What are bronchopulmonary segments?

Answer 4

A:
* Right lung: 3 lobes, 2 fissures (oblique & horizontal).
* Left lung: 2 lobes, 1 fissure (oblique), has a cardiac notch & lingula

A: Independently supplied lung segments; 10 in the right lung, 8-10 in the left lung.

Question 5

5. Blood & Nerve Supply

Q: What supplies blood to the lungs?
Q: What nerves supply the lungs?

Answer 5

A: - Pulmonary arteries: Supply alveoli.
* Bronchial arteries: Supply bronchi & bronchioles (2 left, 1 right).
A: Vagus nerve and sympathetic trunk.

Question 6

6. Mechanism of Respiration

Q: What happens during inspiration?
Q: What happens during expiration?
Q: How do rib movements assist breathing?

Answer 6

A: - Diaphragm contracts & flattens.
* Ribcage expands.
* Thorax volume increases, air enters due to lower pressure.
A: - Diaphragm & ribcage relax.
* Thorax volume decreases, air exits due to higher internal pressure.
A: Bucket-handle & pump-handle movements expand the thoracic cavity during respiration.

Question 7

7. Clinical Relevance

Q: Which bones in the thoracic cage are frequently fractured?
Q: Why is the visceral pleura not pain-sensitive, but the parietal pleura is?

Answer 7

A: Ribs, especially in trauma cases.
A: The visceral pleura has autonomic innervation, while the parietal pleura has somatic innervation (intercostal & phrenic nerves).