Pneumothorax - Physiology and Altered Physiology

Question 1

Pneumo - Respiratory System

Answer 1

a series of organs responsible for taking in oxygen and expelling carbon dioxide. The primary organs of the respiratory system are lungs, which carry out this exchange of gases as we breathe.

Question 2

Pneumo - Anatomy of Respiration

Answer 2

The lungs are located on either side of the thorax.

The trachea conducts inhaled air into the lungs through the bronchi.

The bronchi then divide into smaller and smaller branches (bronchioles).

The bronchioles end in clusters of microscopic air sacs called alveoli.

In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled.

Question 3

Pneumo - Inhalation

Answer 3

1. The intercostal muscles contract, expanding the ribcage up and out.
2. The diaphragm contracts, pulling downwards to increase the volume of the chest.
3. The pressure inside the chest is lowered drawing air into the lungs.

Question 4

Pneumo - Exhalation

Answer 4

1. The intercostal muscles relax, the ribcage drops inwards and downwards
2. The diaphragm relaxes, moving back upwards, decreasing the volume of the chest.
3. Pressure inside the chest increases and air is forced out.

Question 5

Pneumo - Pleura

Answer 5

The pleura are double-layered serous membranes that surround each lung.

Attached to the wall of the thoracic cavity, the parietal pleura forms the outer layer of the membrane.

The visceral pleura forms the inner layer of the membrane covering the outside surface of the lungs.

Between the parietal and visceral pleura is the pleural cavity, which creates a hollow space for the lungs to expand into during inhalation.

Serous fluid secreted by the pleural membranes lubricates the inside of the pleural cavity to prevent irritation to the lungs during breathing

Question 6

Pneumo - defn

Answer 6

A pneumothorax is the presence of air or gas in the pleural space caused by a rupture in the visceral pleura (membrane that covers lungs), or the parietal pleura (membrane on thoracic cavity) and chest wall.

There are 4 types of pneumothorax

Question 7

Pneumo - PSP

Answer 7

Primary Spontaneous Pneumothorax

Often there is no discernible cause, however, the tear often occurs at the site of a tiny bleb or bullae on the edge of a lung.

These are like small balloons of tissue that may develop on the edge of a lung. The wall of the bleb is not as strong as normal lung tissue and may tear. Air then escapes from the lung but gets trapped between the lung and the chest wall.

Most occur in healthy young adults who do not have any lung disease. It is more common in tall thin people.

Question 8

Pneumo - SSP

Answer 8

Secondary Spontatneous Pneumo

This means that the pneumothorax develops as a complication (a secondary event) of an existing lung disease.

This is more likely to occur if the lung disease weakens the edge of the lung in some way. This may then make the edge of the lung more liable to tear and allow air to escape from the lung.

So, for example, a pneumothorax may develop as a complication of chronic obstructive pulmonary disease (COPD) - especially where lung bullae have developed in this disease.

Question 9

Open Pneumothorax

Answer 9

AKA Communicating Pneumo
AKA Sucking chest wound

Caused by an unsealed chest wound, where the surrounding tissues do not cover the wound during inspiration and/or expiration.

Question 10

Tennstion Pneumothorax

Answer 10

If there is a continued entry of air into the chest cavity without any exit, pressure will build in pleural space, which will lead a tension pneumothorax.

When the pressure inside pleural space exceeds atmospheric pressure this pushes against the already collapsed lung, which applies pressure and can displace the heart, great vessels and trachea, causing the diminished capacity in the other lung and impaired blood circulation.

An ongoing pneumothorax can impede a patient from being able to adequately ventilate (SoB, DiB, Tachypnoea, Tachycardia, use of accessory muscles, cyanosis, asymmetrical chest movement)

This then begins to impact the circulatory system negatively as venous return to the heart is reduced. (Hypertension)

In extreme cases the structures within the mediastinal structures can be displaced which leads to venous return being highly compromised. (Hypotension, Jugular Venous Distension, Tracheal Deviation, Distributive Shock)