Blood Gas Flashcards
What is the pH range in the human body?
7.35-7.45
What is Ka
The dissociation constant
Define pKa
The negative log of the dissociation constant
When is the body in acid-base balance?
PH = pKa
What does a buffer consist of?
A weak acid and a salt of its conjugate base
What is the function of a buffer?
To allow a solution to resist changed in pH upon adding acid or base
What is the most important buffering system in the body?
H2CO3 (bicarbonate)
What organ in the body changes HCO3 concentration?
Kidneys
What organs regulate the acid base balance (transport of CO2)?
Lungs and Kidneys
_____ is the end product of most aerobic metabolic processes.
CO2
Dissociation of __a__ causes the development of a concentration gradient due to the increase in __b__ concentration within the RBC.
A) H2CO3
B) HCO 3-
How do the kidneys regulate pH?
- excreting acid (primarily in the ammonium ion)
- reclaiming HCO3- from glomerular filtrate
The dissolved carbon dioxide (dCO2) that is expelled by the lungs is known as the ___
Respiratory component
How the kidneys control the bicarbonate concentration by reabsorption or excretion is known as the ___
Metabolic component
Acidemia/Acidosis
When the blood pH is less than the reference range
Causes of acidosis include
1) primary metabolic imbalance: the amount of acid exceeds the capacity of the buffer systems and there is a decrease in bicarbonate
2) primary respiratory imbalance
How does the body compensate for metabolic acidosis?
Hyperventilation
Alkalemia/alkalosis
When blood pH is greater than the reference range
Cause of primary respiratory alkalosis
Increased rate of alveolar ventilation which causes an excessive elimination of CO2 by the lungs
How do the kidneys compensate for primary respiratory alkalosis?
By excreting HCO3- in the urine and reclaiming H+ to the blood through decreased activity of Na+ and H+ exchange
-osis
Refers to a process in the body
-emia
Refers to the corresponding state in blood
Acidemia
Will result if the hydrogen ion concentration increased through pCO2 concentration or decreases in the bicarbonate concentration
Alkalemia
Will result if the H+ concentration decreases, either from decreased PCO2 or increased concentration of bicarbonate