$[H^+] = 5.25 \times 10^{-8}\ \mathrm{M}$

Question 1

Which of the following best describes the role of the carbonic acid-bicarbonate buffer system in maintaining blood pH?

Accepted Answer

It maintains blood pH by shifting equilibrium between $CO_2$, $H_2CO_3$, and $HCO_3^-$ according to Le Chatelier's Principle.

Question 2

A patient’s blood pH is measured at 7.28. Which condition does this indicate, and what is a likely symptom?

Accepted Answer

Acidosis; lethargy

Question 3

Which equation correctly relates hydrogen ion concentration $[H^+]$ to pH?

Accepted Answer

$pH = -\log_{10}[H^+]$

Question 4

If Eugene’s blood pH is 7.28, what is the approximate concentration of hydrogen ions $[H^+]$ in his blood?

Accepted Answer

$[H^+] = 5.25 	imes 10^{-8}\ \mathrm{M}$

Question 5

Which organ systems are primarily responsible for regulating blood pH in response to acidosis?

Accepted Answer

Respiratory and urinary systems

Question 6

According to Le Chatelier’s Principle, what happens to the equilibrium of the carbonic acid-bicarbonate system when blood $CO_2$ levels increase?

Accepted Answer

The equilibrium shifts to produce more $H_2CO_3$ and $H^+$, lowering pH.

Question 7

Which of the following is a common cause of metabolic acidosis?

Accepted Answer

Excessive loss of bicarbonate through diarrhea

Question 8

A patient is hyperventilating. According to the carbonic acid-bicarbonate buffer system, what effect will this have on blood pH?

Accepted Answer

Blood pH will increase due to decreased $CO_2$ and $H^+$ concentration.

Question 9

Which feedback loop best describes the body’s response to low blood pH?

Accepted Answer

Chemoreceptors detect low pH, respiratory rate increases, $CO_2$ is expelled, pH rises.

Question 10

Which of the following is NOT a function of sodium, potassium, or magnesium ions in the body?

Accepted Answer

Regulation of DNA repair mechanisms

Question 11

Why is a blood pH of 7.0 considered abnormal for humans?

Accepted Answer

It is below the normal physiological range and indicates acidosis.

Question 12

Which of the following best explains why buffers are important in blood?

Accepted Answer

They minimize changes in pH by accepting or donating $H^+$ ions.

Question 13

A patient with chronic kidney disease is at risk for which acid-base imbalance, and why?

Accepted Answer

Metabolic acidosis; kidneys cannot excrete $H^+$ efficiently.

Question 14

Which of the following is a symptom of alkalosis?

Accepted Answer

Muscle fatigue and twitching

Question 15

Which process in the urinary system helps correct acidosis?

Accepted Answer

Excretion of $H^+$ ions and reabsorption of $HCO_3^-$

Question 16

Which of the following best represents the relationship between pH and $[H^+]$?

Accepted Answer

As $[H^+]$ increases, pH decreases.

Question 17

Which of the following scenarios would most likely result in respiratory acidosis?

Accepted Answer

Hypoventilation leading to increased $CO_2$ retention

Question 18

Which general model of physiology is most useful for predicting how changes in $CO_2$ affect blood pH?

Accepted Answer

Le Chatelier’s Principle

Question 19

Which of the following is a real-world example of homeostatic control in response to blood pH deviation?

Accepted Answer

Increased breathing rate after intense exercise to expel excess $CO_2$

Question 20

Which of the following statements about the pH scale is correct?

Accepted Answer

A solution with pH 4 has 1000 times more $[H^+]$ than a solution with pH 7.

Physiology, pH Balance, and Electrolytes: Study Notes for Anatomy & Physiology

Study Guide - Practice Questions