Respiratory Dead Space

aka BSCC Physiology 011

Basic Science in Clinical Context Examination: 2 minutes long in 2 parts.

  • Exam candidate answering a question (under exam conditions)
  • Professor providing a more detailed explanation (with transcript)
Regarding the respiratory dead space. Please explain the differences between the anatomical dead space and the physiological dead space in the lung
Examinee response: Drawing and explanation in real-time video/audio
Examiner Explanation

Respiratory Dead Space

The anatomical dead space is that space of the brachial tree that does not take place in gaseous exchange. In other words it is a space, which includes air traveling down the trachea bronchi and bronchioles but no to the alveoli.

The anatomical dead space can increase with a large inspiration due to the traction or pull exerted on the bronchi by lung parenchyma.The physiological dead space is those zones in the lung in which there is no elimination of CO2 in other words there is ventilation of the alveoli but no perfusion.

This physiological dead space occurs in diseased lung states only. In health individuals there is perfusion and ventilation in the alveoli and therefore the physiological dead space is often zero.

BSCC Basic Science in Clinical Context 700 2

Basic Science

in Clinical Context

Emergency Physician, FACEM. Visual & kinaesthetic learner. Multi-modal teacher. Occasional filmmaker. | @drdeannechiu |

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