Midterm 1 Flashcards
define isohydria
concentration of hydrogen ions
pH is equal to …
-log 10 (H+)
What is a buffer?
solution that can maintain a nearly constant pH
Particularity of a buffer solution
resists to pH changes
Typical buffer solution
weak acid/base + one of it’s salts
Most important physico-chemical buffer
carbonic acid - bicarbonate buffer system
What is the carbonic acid - bicarbonate buffer system
CO2 + H2O –> H2CO3 –> H+ + HCO3-
Which organs form the vital buffer system?
Kidneys and Lungs
When H+ increases what happens to CO2
equation moves to the left, so CO2 increases
Equation of excretion of H+ by lungs
(increase)H+ + HCO3- –> H2CO3 –> H2O + (increase)CO2
Define Kussmaul breathing, and when does it happen?
normal frequency of breathing but very deep inspiration and expiration, when CO2 is being excreted
What is the kidney’s buffering capacity?
Can retain or excrete H+
When CO2 increases what happens to H+
equation moves to the right , H+ AND HCO3- increases
What kind of blood sample is needed to asses respiratory functions?
Arterial blood
What kind of blood sample is needed to asses metabolic status?
Venous or arterial sample
Why is air contamination avoided while sampling blood?
pO2 would increase and pCO2 would decrease (shortly after) or increase after long period of time
What can be calculated based on the pH and CO2?
HCO3- and ABE
Which are the metabolic parameters?
HCO3- (TCO2)
ABE
Give a respiratory parameter
pCO2
Give the blood pH reference range
7.35 - 7.45
An increase of CO2 can be called
a shift in “acidic” direction
impaired gas exchange in the lungs, remaining CO2:
Respiratory acidosis
Hyperventilation :
respiratory alkalosis
What happens to HCO3- in acidosis
decreases