$$[H^+] = 1 \times 10$$^{-4}$$ M$$

Question 1

Which of the following best describes the relationship between pH and hydrogen ion concentration $$[H^+] in a $$solution?

Accepted Answer

pH is equal to the negative log of $$[H^+]$$: $$pH = -\log([H^+])$$

Question 2

A patient presents with a plasma pH of 7.30, elevated $$PCO_2$$, and elevated $$HCO_3$$^-$$. Which acid-base disturbance is most likely?

Accepted Answer

Respiratory acidosis

Question 3

Which of the following is the primary buffer system in the human body for regulating plasma pH?

Accepted Answer

Bicarbonate buffer system: $$H^+ + $$HCO_3$$^- \rightleftharpoons CO_2$ + H_2O$$

Question 4

If a person is hyperventilating, what is the expected effect on blood pH and why?

Accepted Answer

Blood pH increases due to decreased $$CO_2$$

Question 5

Which of the following scenarios would most likely result in metabolic alkalosis?

Accepted Answer

Repeated vomiting leading to loss of stomach acid

Question 6

What is the effect of acidosis on the excitability of neurons and the central nervous system?

Accepted Answer

It reduces neuronal excitability, potentially leading to coma

Question 7

Which of the following best explains why the kidneys are essential for long-term acid-base balance?

Accepted Answer

They excrete or reabsorb large amounts of $$H^+$$ and $$HCO_3$$^-$$ as needed

Question 8

A solution has a pH of 4. What is the hydrogen ion concentration $$[H^+] in $$this solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-4}$$ M$$

Question 9

Which of the following is a major source of acid in the human body?

Accepted Answer

Metabolism of amino acids and fatty acids

Question 10

A patient with chronic kidney disease is unable to excrete $$H^+$$ efficiently. What acid-base disturbance are they most at risk for?

Accepted Answer

Metabolic acidosis

Question 11

Which of the following best describes the effect of slower, shallower breathing on blood pH?

Accepted Answer

It increases $$CO_2$$ retention, leading to a decrease in pH

Question 12

Which of the following is true regarding the normal range for plasma pH in humans?

Accepted Answer

It is between 7.38 and 7.42

Question 13

Which of the following best explains why the body spends more time eliminating acids than bases?

Accepted Answer

There are more dietary and metabolic sources of acids than bases

Question 14

A patient is found to have low pH, low $$CO_2$$, and low $$HCO_3$$^-$$. What is the most likely diagnosis?

Accepted Answer

Metabolic acidosis

Question 15

Which of the following is a direct effect of alkalosis on the nervous system?

Accepted Answer

Increased CNS excitability, muscle twitching, and cramps

Question 16

Which of the following equations correctly represents the dissociation of water?

Accepted Answer

$$H_2O \rightleftharpoons H^+ + OH^-$$

Question 17

Which of the following best describes the role of buffers in the body?

Accepted Answer

They lessen changes in pH by absorbing or releasing $$H^+$$

Question 18

Which of the following would NOT be a likely cause of respiratory acidosis?

Accepted Answer

Hyperventilation

Question 19

If the plasma pH is 7.50, $$PCO_2 is $$low, and $$HCO_3$$^-$$ is low, what is the most likely acid-base disturbance?

Accepted Answer

Respiratory alkalosis

Question 20

Which of the following best describes the compensation for metabolic acidosis?

Accepted Answer

Increased ventilation to expel $$CO_2$$

Acid–Base Balance and pH Regulation in the Human Body

Study Guide - Practice Questions