Some more notes on the respiratory system

As I promised in my last post, here are some notes on the respiratory system.

1. Define the pleural space anatomically.

The pleural space is the area between the parietal pleura and the visceral pleura (the connective tissue lining the chest wall and lungs, respectively). It is filled with a lubricating fluid to allow the lungs to expand and contract.

2. Would tracheostomy help in the case of a severe asthma attack? If so, why? If not, why not?

Tracheostomy would not help in the case of an asthma attack. A tracheostomy is an operation which allows patients with blocked larynxes to breathe by inserting a tube lower down in the trachea, allowing air to bypass the larynx. Asthma, however, affects the smooth muscles near the alveoli, which is far past the area bypassed by a tracheostomy.

3. What muscles are involved in respiration during severe exertion? How is that different from respiration at rest?

During severe exertion, the accessory muscles of respiration are also involved (as opposed to only the diaphragm being involved as during rest). These muscles include the external and internal intercostal muscles, the sternocleidomastoid muscle, the scalene muscles and the rectus abdominus.

4. What is a pneumothorax? Describe the events that occur in the chest after a gunshot wound that creates a hole in the chest wall.

A pneumothorax is a loss of the vacuum in the pleural cavity following a tear in the visercal and/or parietal pleura. This loss of vacuum causes the lung to collapse.

After a gunshot wound causing damage to the parietal pleura and probably the visceral pleura as well, air rushes into the pleural cavity, causing a loss in vacuum. The decreased pressure causes the lung to collapse, which in turn stops gas exchange in the lung.