Physiological dead space

Definition

Physiological dead space is the portion of the respiratory system where gas exchange does not occur, including both anatomical dead space and any alveoli that are not functioning properly. This space contributes to inefficiencies in breathing by reducing the amount of oxygen that reaches the bloodstream.

5 Must Know Facts For Your Next Test

1. Physiological dead space includes anatomical dead space plus any non-functional alveoli.
2. It can be increased in conditions such as pulmonary embolism or chronic obstructive pulmonary disease (COPD).
3. The measurement of physiological dead space helps assess the efficiency of ventilation.
4. A higher physiological dead space means less effective gas exchange and potential hypoxemia.
5. It is typically measured using a combination of tidal volume, arterial blood gases, and expired CO2 levels.

Review Questions

• What components make up physiological dead space?
• How can pathological conditions affect physiological dead space?
• Why is measuring physiological dead space important for understanding respiratory efficiency?

Related terms

Anatomical Dead Space:

The volume of air in the respiratory tract that does not participate in gas exchange, including the trachea and bronchi.

Tidal Volume:

The amount of air inhaled or exhaled during normal breathing.

Alveolar Ventilation: The process by which fresh air reaches the alveoli where gas exchange with the blood occurs.