19 Rs Rs Ventilation

19 Rs Rs Ventilation - RESPIRATORY VENTILATION AC Brown...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: RESPIRATORY VENTILATION AC Brown Page 1 A7c VENTILATION PARAMETERS A. Lung Volumes 1. Basic volumes: elements a. Tidal Volume (V T , TV): volume of gas exchanged each breath; can change as ventilation pattern changes b. Inspiratory Reserve Volume (IRV): maximum volume that can be inspired, starting from the end inspiratory position (potential volume increase at the end of inspiration) c. Expiratory Reserve Volume (ERV): maximum volume that can be expired, starting from the end expiratory position (potential volume decrease at the end of expiration) d. Residual Volume (RV): volume remaining in the lungs and airways following a maximum expiratory effort (note: lungs cannot empty completely because of (1) stiffness when compressed and (2) airway collapse and gas trapping at low lung volumes) 2. Capacities: combined volumes a. Vital Capacity (VC): maximum volume of gas that can be exchanged in a single breath VC = TV + IRV + ERV b. Total Lung Capacity (TLC): maximum volume of gas that the lungs (and airways) can contain TLC = VC + RV = TV + IRV + ERV + RV c. Functional Residual Capacity (FRC): volume of gas remaining in the lungs (and airways) at the end expiratory position FRC = RV + ERV d. Inspiratory capacity (IC): maximum volume of gas that can be inspired from the end expiratory position IC = TV + IRV RESPIRATORY VENTILATION AC Brown Page 2 A7c VENTILATION PARAMETERS (continued) A. Lung Volumes (continued) 3. Measurement of volumes: Spirometer/Spirometry 4. Typical Values (young male of average size) TV = 0.5 L (10% TLC) VC = 4.8 L ( ≈ 5 Liters; 80% TLC) IRV = 3.0 L (50% TLC) TLC = 6.0 L ERV = 1.3 L (20% TLC) FRC = 2.5 L RV = 1.2 L (20% TLC) IC = 3.5 L Note: "normal" values depend upon age, sex, and size Note: the above percentages for TV, IRV, and ERV are for a person at rest breathing normally; RV, VC, and TLC do not depend on whether the person is at rest or is breathing more vigorously B. Ventilation 1. frequency or respiration rate (f or RR): breaths per unit time typical value at rest: 12/min (but much individual variation) 2. ventilation rate: total volume inspired or expired per unit time (written as V’ or V-dot); sometimes called Minute Volume (MV) when measured per minute; to avoid ambiguity, usually measured as volume expired, V E ’ MV or V E ’ = f × TV typical value at rest: MV or V E ‘ = 12/min × 0.5L = 6 L/min RESPIRATORY VENTILATION AC Brown Page 3 A7c VENTILATION PARAMETERS (continued) B. Ventilation (continued) 3. maximum air flow rate, single breath 6 5 4 3...
View Full Document

This note was uploaded on 01/03/2012 for the course BIO 308 taught by Professor Acbrown during the Spring '10 term at Portland.

Page1 / 8

19 Rs Rs Ventilation - RESPIRATORY VENTILATION AC Brown...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online