# Kinesiology 2230A/B Study Guide - Pressure Gradient, Partial Pressure, Total Pressure

34 views2 pages
Published on 12 Apr 2013
School
Western University
Department
Kinesiology
Course
Kinesiology 2230A/B
Professor
Lecture 2
Birds
- Takes huge amount of energy and O2 to start flying
- Higher up in the sky, less atmospheric pressure
- Into the lung via air sacs, out via the windpipe
o Allows for near constant, one-way air flow through their lungs
- Fresh never mixes with stale air
- Every flap of wings, air moves in and out
- Inhale, lungs fill up, exhale, air sacs get pushed forward
- Air posterior first then anterior therefore always have fresh air in lungs
- Maintains good partial pressure
Compostion of Air
- Nitrogen, oxygen, argon, carbon dioxide
- N2 is most abundant
- Very little Ar and CO2
- As altitude increases, partial/barometric pressure decreases
- Gravity attracts gases
Gas Pressures and Exchange
- Gas diffuse from high to low pressure
- Total pressure = sum of partial pressures (Dalton’s Law)
- 79% nitrogen, 21% oxygen, 0.03% CO2
- If barometric pressure = 760mmHg
o PO2= 760mmHg x 20.93% = 159 mmHg
Sea level (changes with weather)
% becomes .2093
o PCO2 = 760 x .0003 = .23 mmHg
o PN2 = 760 x .7904 = 600 mmHg
- Henry’s Law: gases dissolving in liquid are in proportion to PP’s
Pressures
- At the end of inspiration
o Chest wall: contained, as it expands volume increases, pressure decreases
o Pressure gradient moves things in between gas in alveoli and drives O2 into lungs
- At end of expiration
o Pressure in intrapleural space will be increasing meaning space will be reduced
o Pressure gradient still present due to elasticity of chest wall, still wants to contract
- If negative pressure is lost, the lung will collapse
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

## Document Summary

Takes huge amount of energy and o2 to start flying. Higher up in the sky, less atmospheric pressure. Into the lung via air sacs, out via the windpipe: allows for near constant, one-way air flow through their lungs. Every flap of wings, air moves in and out. Inhale, lungs fill up, exhale, air sacs get pushed forward. Air posterior first then anterior therefore always have fresh air in lungs. Gas diffuse from high to low pressure. Total pressure = sum of partial pressures (dalton"s law) If barometric pressure = 760mmhg: po2= 760mmhg x 20. 93% = 159 mmhg. % becomes . 2093: pco2 = 760 x . 0003 = . 23 mmhg, pn2 = 760 x . 7904 = 600 mmhg. Henry"s law: gases dissolving in liquid are in proportion to pp"s. At the end of inspiration: chest wall: contained, as it expands volume increases, pressure decreases, pressure gradient moves things in between gas in alveoli and drives o2 into lungs.