Acid-Base Balance Flashcards
Definition:
Chemical system that prevents a radical change in the fluid pH by dampening the change in H+ ions
Buffer
Definition:
Weak acid
takes up hydroxyl ions
Definition:
Weak base
takes up H+ ions
Rank the systems that regulate pH from fastest to slowest
- chemical buffers
- respiratory tract
-renal system
What is the most important protein buffer?
hemoglobin
How does hemoglobin act as a buffer?
By forming carbonic acid in the erythrocyte with CO2 and water which dissociates into bicarb and H+
The H+ ions are buffered by hemoglobin molecules (Bohr effect) which helps facilitate oxygen to be released at the tissues and reduces hemoglobin
What acts as the acid and the base in the bicarbonate-carbonic acid buffer system?
Base: Bicarbonate ions
Acid: Carbonic acid
What is the ratio of Bicarb to carbonic acid in the blood? Why is this helpful?
20:1
useful because most of the body’s metabolic wastes are acids
How does the respiratory system contribute to the balance of acids and bases?
By regulating blood levels of carbonic acid
Acid-base balance
What happens when you increase breathing?
Decrease in CO2 and H+ causeing a temporary inc in blood pH
Acid-base balance
What happens when you decrease breathing?
Inc in CO2 and H+ causing a temporary dec in blood pH
How does renal regulation affect the acid-base balance?
By controlling levels of bicarbonate in the blood
Cells of the tubule are not permeable to bicarb so instead it is transported as CO2 and water into the collecting duct, where it is reformed into carbonic acid which then dissociates again
Definition:
Blood pH below 7.35
acidosis
Definition:
Blood pH above 7.45
alkalosis
What is the major effect from acidosis? Symptoms?
Depression of the central nervous system
Symptoms:
- headache and confusion
- lethargic and easily fatigued
What is the major affect of alkalosis? Symptoms?
Over-excitability of the central and peripheral nervous sytems
Symptoms:
- cognitive impairment
- tingling or numbness
- muscle twitching and spasm
- nausea and vomiting
T/F: changes in pH do not alter enzymes
false! they alter the shape casuing them to become non-function which affects metabolic activity
What is complete compensation? Partial?
Complete: pH brought back into normal range
Partial: pH brought close to normal range
Definition:
Increase PaCO2 >45mmHg causing pH to drop <7.35
Respiratory acidosis
Definition:
Respiratory alkalosis
PaCO2 <35mmHg causing pH to increase >7.45
Definition:
HCO3- <22 mEq/L causing pH to drop <7.35
Metabolic acidosis
Definition
HCO3- >26 mEq/L causing pH to increase >7.45
If a person has alter pH for respiratory reasons, what system will compensate?
Urinary system
What causes respiratory acidosis?
Hypoventilation or other causes of reduced gas exchange in the lungs
