Home > Uncategorized > Respiratory Physiology Lecture 8 Notes: Pulmonary Gas Exchange

Respiratory Physiology Lecture 8 Notes: Pulmonary Gas Exchange


Today, we will spend 56 minutes on the ventilation perfusion ratio, the fourth cause of hypoxia. 



Ventilation perfusion ratio is the most common cause of impaired gas exchange, it’s the most complicated and misunderstood mechanism. 

He uses ventilation as a word for ‘breathing.’ 

Va/Q is the ventilation perfusion ratio or VPR. 

No Ventilation pO2 = 40, pCO2 = 45

Normal Ventilation pO2 = 100, pCO2=40

Blood Flow Obstruction pO2=150, pCO2 0

When Va/O is zero, no air is coming in.

When Va/O is infinite, no blood enters.

He shows an oxygen carbon dioxide diagram.

There is a VPR gradient down the lung.  The bottom of the lung gets alot of blood, the top gets little.  Ventilation decreases as we go up the lung.  Gravity causes the blood flow gradient. 

Va/Q is low at the bottom and high at the top of the lung. 

Va from 34 down to 82 and Q from 0.7 to 1.3 down at the bottom.  So, 132 to 89 VPR. 

Pulmonary TB is most common at the top of the lung, because the bacteria likes oxygen rich environments.  In bats, PTB is most common in the bottom of the lungs, as they hang upside down. 

The pH is higher in the top of the lung than the bottom.  Metastatic calcification is bone being laid down in the lungs. 

The VPR determines the efficiency of gas exchange. 

Va/Q = 1/10  O2=14.6

Va/Q =10/10 O2=19.5

Va/Q = 10/1 O2=20

emphysema, bronchitis- a disease of the airways

Stages of Impaired Gas Exchange

Normal – Uneven ventilation and blood flow – Fall in pO2, Rise in pCo2, Increased ventilation

The body is very jealous of pCO2.  It maintains it closely. 

PaO2 = PiO2 – PaCO2/R + F

PaO2 = 149 -60/.8 = 74 mmHg

A change = 74-50 = 24 mmHg 


4 carbons overwhelm hydrogen bonding

Atmosphere: troposphere, stratosphere, mesosphere, thermosphere, ionosphere, exosphere

CTLSC 7 12 554

Sextuple Bond: Mo2, W2

Intermolecular Bonding: electrostatic, h bonding, dipole dipole, van der Waals

Hydrogen Bonding: FON Cl

Mandatory Refusal – when communications are lost, no one is trusted. A breach is assumed.

Gain Band Width Product = Gain x Bandwidth

CARVER is an acronym that stands for Criticality, Accessibility, Recuperability, Vulnerability, Effect and Recognizability.

Wind Speed Beaufort Category How to Judge the Wind
1-3 mph Light Air Smoke drifts. Wind cannot be felt.
4-7 mph Light Breeze Wind felt on face. Leaves rustle. Weather vanes move.
8-12 mph Gentle Breeze Leaves and twigs in motion. Light flags are extended.
13-18 mph Moderate Breeze Wind raises dust and loose papers. Small branches move. Flags flap.
19-24 mph Fresh Breeze Small trees in leaf sway slightly. Wavelets form on ponds and lakes.
25-31 mph Strong Breeze Large branches move. Telephone lines sing.

Visible Light – 400 to 700 nm

adam boy charles david edward frank george henry ida john kevin lincoln mary nora ocean paul queen robert sam tom union victor william xray young zebra
bull spread buy near, sell far
bear spread sell near, buy farcash – futures = basis

spreads are differences between futures contract months
cashpostive carry
cash>futures negative carry (inverted)
Basis: time space quality

Aromatic: planar, cyclic, Huckels Rule – 4n+2 electrons

Fibrous – sclera, cornea

Sensory – retina

Vascular – choroid, iris, pupil, ciliary body

Kingdoms – monera, protista, fungi, plant, animal

HSbF6 pKa = 25

Electrophiles are positive, nucleophiles are negative

EDTA is a tetraprotic acid.

Tissue: nervous muscular epithelial connective

Epithelial: simple stratified pseudostratifed/ cuboidal columnar squamous

I. The output attempts to do whatever is necessary to make the voltage difference between the inputs zero.II. The inputs draw no current

Adrenal cortex (outer layer)

glucocorticoids – cortisol

mineralcorticoids – NaCl


Adrenal Medulla – epinepherine

Intermolecular forces: electrostatic, h bonding, dipole dipole, vdW

Bonds: Ionic >1.9, polar covalent, covalent <0.4

Categories: Uncategorized
  1. Roger U
    November 13, 2012 at 10:20 pm

    Yo, Ryu, come back to AP. I replied to your comment.

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