Lec 19 Ventilatory Control Flashcards
What is the definition of avo2 difference
The difference between the oxygen content of arterial blood vs mixed venous blood
How would you calculate avo2 difference
Cao2 - Cvo2
Arterial - venous
At rest what is the bodies avo2 difference
40-50 ml o2/ L blood
What is the o2 content of blood leaving the lungs
What is the o2 saturation as a percentage
16-24 ml/100ML blood
95-98%
What is avo2 difference at rest
What is the percentage of o2 uptake
4-5ml/100ML
25% o2 uptake
During intensive aerobic exercise what happens o2 extraction
What are the values
What is the percentage
Increases
15-20ml/100 ML
75-100%
With increase exercise intensity what happens to the arterial and venous blood
Venous blood content is the only one to change
O2 content during exercise on the venous side gets way lower
Arterial side/ oxygen delivery stays the same
Which factors would change on exercise intensity
O2 extractions and venous blood content
What are the three ways the blood Carrie co2
What are the percentages of each
Dissolved In solution
Total 10% (5% plasma and 5% in RBC)
Transported as bicarbonate
Total 65%
Carbamino compounds (most,y bound to hemoglobin)
Total 25% (5% in plasma and 20% in RBC)
What do buffers do
They resist changes in ph aka concentrations oh H+
When ph drops buffers absorb h+
When ph increases buffers release h+
What are the two different type of buffer systems
Chemical and physiological
What are the three types of chemical buffers
Phosphate
Bicarbonate
Protein (hemoglobin)
What is physiological buffers system in the body
Ventilatory
Increasing ventilation does what
Lowers Paco2
Allows more co2 to diffuse into the lungs to be exhaled to the environment
What does adding sodium carbonate during exercise do
Act as a extracellular buffer and increase performance (delay fatigue)
What process causes gas exchange in the lungs and muscles
Diffusion
The lungs help to …
Buffer ph by re,owing co2
The binding of o2 to Hb promotes what
Co2 and h+ release
What the chemical reactions at the level of he tissues and level of the lungs
What happens when you add more co2
Tissues
Co2+h2o ——> h2co3 ——> h+ + hco3-
Lungs
h+ + hco3- ——> h2co3 ——> Co2+h2o
Adding more co2 push the reaction to more hco3-
What is the steps of carbon dioxide transport
1) co2 produced by cellular metabolism diffuses into the bloodstream
2) co2 combines with water forimimg CARBONIC ACID H2co3
3) carbonic acid then dissociates into H+ and BICARBONATE IONS Hco3-
4) bicarbonate ions act as a buffer by reacting with excess H+ to form CARBONIC ACID, which is then converted BACK to CO2 and exhaled
What plays an indirect role to buffering system
PLASMA PROTEINS (albumin)
Play a role in maintaining ph homeostasis
Reservoir for hydrogen ions - can bind or release hydrogen ions
- contributes to the buffering capacity of the blood
INDIRECTLY
