University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

435

Pages:

2
Author:

Mariam A. A.

ANATOMICAL & PHYSIOLOGICAL DEAD SPACE ANATOMICAL DEAD SPACE Conducting Space trachea bronchioles (gen 1-14) without alveoli PHYSIOLOGICAL DEAD SPACE ↓ blood supply to alveoli ↓ O2 delivery to alveoli Alveolar Dead Space Alveolar Dead Space + Anatomical Dead Space = Physiological Dead Space ALVEOLUS AIR CONDUCTING ZONE NO GAS EXCHANGE Anatomical Dead Space MAINSTEM BRONCHI CANNOT EXTRACT O2 FROM THIS AIR CAPILLARY Exhale Part to be exhaled out into anatomical dead space Inhale new oxygenated air old deoxygenated air enters bronchi What will remain after exhaling? used for gas exchange old deoxygenated air Dead Space air after inhale - fresh air from environment after exhale - air from alveoli Calculating Dead Space - Using Bohr equation for physiological dead space In a Well-Functioning Alveolus CO2 diffuses into blood until PCO2 in blood equals PCO2 in alveolar air Assumptions no O2 in environment no CO2 stored in dead space all CO2 comes from functional alveoli Tidal Vol. VT = VD + VA Vol. of air in alveoli VA Amount of CO2 in alveolar gas MA = VA * CA Amount of CO2 in exhalation MT = VT * CT Assumption: All CO2 from functional alveoli MA = MT Therefore: VA * CA = VT * CT VA = (VT * CT) / CA Sub 2 into 1 VD = VT - (VT * CT) / CA VD = VT * (1 - CT/CA) Sub 4 into 2 VD = VT * (PA - PT) / PA