-
Oxygen is requires at the cellular level to produce energy in the form of ATP, the body's energy molecule in a process known as...
Oxidative phosphorylation
-
Cellular energy production begins with..
The metabolism of glucose
-
Define glycolysis
Glucose is converted to two molecules of pyruvic acid. Produces two atp molecules as a result. Does not require oxygenation.
-
What happens with glucose when oxygen is not present?
The pyruvic acid molecules are converted to lactic acid along with the production of two more atp. Lactic acid builds up and changes the tissue ans blood ph.
-
If oxygen is available the pyruvix acid molecules enter what is known as the..
Krebs cycle
-
What is the Krebs cycle?
Produces additional energy in the form of 32-34 additionak atp molecules from a single glucose molecule.
-
Oxygen is required as an electron transport molecule in this process and is used up
Aerobic respiration
-
Involves both gas exchange and transport
Respiration
-
Involves the movement of gases across a physiologic barrier
Respiration
-
Gases must cross the alveolar-capillary membrane in a process called
External respiration
-
At the tissues, gases must cross the capillary-tissue cell membrane and this is referred to as
Internal respiration
-
The movement of gas molecules from an area of high concentration to an area of lower concentration until equilibrium is reached
Diffusion
-
Individual gas partial pressure differences
Diffusion gradient
-
All molecules of all gases move in the same direction due to a total pressure gradient
Bulk flow
-
Air moves through the conducting airways by
Bulk flow
-
Movement of gas in the respiratory zone is due to
Diffusion
-
What is ficks law
A*D*(p1-p2)/T
-
Diffusion will decrease if what decreases
Thickness of membrane
-
Disease processes such as what reduce the surface area for diffusion and effect respiration
Emphysema
-
Henrys law
Amount of gas that dissolves in a liquid at a given temp. Is proportional to the p.p. of the gas.
-
What is the solubility coefficient for oxygen
.0244
-
What is the solubility coefficient for CO2
.592
-
In a lquid, co2 is how many times more soluble than oxygen?
24x
-
What diffused faster, co2 or o2?
O2 bc it is lighter . 32 gmw vs 44gmw for CO2
-
The more soluble and lighter the gas, the faster/slower it diffuses
Faster
-
CO2 diffuses how many more times than o2?
20x
-
The amount of gas that diffuses for each mmHg of pressure.
Diffusion coefficient. Equal to solubility of the gas divided by the square root of the gmw
-
What is normal venous PO2?
40mmhg
-
What is normal PAO2?
100mmhg
-
What is the diffusion gradient from the alveoli to the capillary of the blood?
60mmhg
-
What is the normal venous CO2
46mmhg
-
What is the normal PACO2
40mmhg
-
What is the normal diffusion gradient from the capillary blood to the alveoli
6mmhg
-
Diffusion time for O2 across tbe a-c membrane is
.25 sec to reach equilibrium
-
Normal blood transit time through the pulmonary capillaries is
.75 sec
-
What ficks law factors limit O2 diffusion?
Thickness of membrane,pressure gradient, surface area
-
In order for oxygen to diffuse from the alveoli into the capillary blood, it must diffuse thru what diffusion path?
Surfactant layer, alveolar epithelium, alveolar basement membrane, interstitial tissue, basement membrane of capillary endothelium, plasma, erythrocyte membrane
-
Name 5 abnormal conditions that can increase the diffusion path, decreasing diffusion. Also decrease compliance and result in poor vent. And oxygenation
Thickening of the alveolar capillary walls, interstitial edema, interstitial fibrosis, alveolar fluid, dilated pulmonary capillaries
-
Where ventilated alveoli are in contact with perfused capillaries
Diffusion surface area
-
The time available for diffusion is determined by
Blood flow
-
The Amount of oxygen which can cross the ac membrane is limited by blood flow through the capillary
Perfusion limited
-
The movement of o2 across the ac membrane is limited by the membrane itself
Diffusion limited
-
Perfusion limited gas flow, does not bind to hb, remains dissolved in plasma, pp rises until equilibrium is reached, when reached diffusion stops
N2o
-
Diffused across membrane rapidly, combines with hg 210x as readily as o2, none remains dissolves in plasma, equilibrium never reached, diffusion continues
CO
-
What can increase o2 diffusion limitation
Low cardiac output or anemia
-
Pathological conditions that can cause diffusion limitation
Atelectasis, alveolar wall thickening, alveolar consolidation, pulmonary edema, interstitial fibrosis, emphysema
-
Arterial blood reflects
Pulmonary gas exchange
-
Mixed venous blood values reflect
Tissue gas exchange
-
Boyles law
T constant, p inverse with v
-
Charles law
P constant, v and t vary directly
-
Gay-lussacs law
V constant, p and t vary directly
-
Daltons law
Mix of gases, total p equal to sum of pp of each individual gas
-
Lung gas mix normally consist of
Oxygen, nitrogen, carbon dioxide, water vapor
-
Partial pressure of water vapor is determined by what
Temperature and relative humidity
-
What is the normal pp of N2
573 mmhg at normal barometric pressure
-
Only the partial pressure of what vary normally in the lungs?
O2 and CO2
-
Alveolar air equation
(Pb-ph2o)FIO2-(PaCO2/.8)
-
Normal PaCO2 range
35-45 mmhg
-
At rest, pulmonary capillary blood removes how much O2? How much CO2 diffuses into the alveoli?
250ml/min, 200
-
Deadspace
Vent without perfusion
-
Shunt
Perfusion without vent
-
What type of blood dumps into the pulmonary vein before it enters the left atria of the heart?
Brochiak venous blood
-
Oxygen is carried in the blood in two forms
Dissolved in the plasma, Bound to hemoglobin
-
Determines the rate and direction of diffusion in the lungs and body tissues
PO2
-
There are approximately how many hb molecules per rbc?
280 million
-
What is a saturated hb molecule
Hb molecule with 4 oxygen molecules
-
Each gram of hb can carry how much O2 per 100% saturation?
1.34 ml
-
Normal hb for male and female
-
The total of the amount carried bound to hb and the amount dissolved in plasma. What is the formula?
Total oxygen content. 1.34*hb*Sao2*pao2*.003
-
-
Arterio venous difference equation
5% volume
-
Cardiac output from ficks equation
Vo2/c(a-v)o2*10
-
Go2, whole body o2.consumption equation
At*ca-vo2*10
-
Do2 tissue oxygenation function equation
Cao2 * qt or cao2 * co * 10
-
Oxygen delivery is dependent on what?
Hb saturstions, hb level, and cardiac output
-
Oxygen extraction ratio
O2er = vo2/do2
-
Svo2 is a measure of what
Reserve o2 supply
|
|