DSM 27.5

Acid is a natural byproduct of many metabolic processes. Which of the following does not contribute to an increase in H+? - H+ is increased by expiration of CO2 by the lungs - H+ is increased by muscle metabolism - H+ is increased by cellular respiration - H+ is increased by the diet along the digestive tract

H+ is increased by expiration of CO2 by the lungs

What is the kidney's response to acidosis?

Secretion of H+ into urine

Which of the following is NOT a buffer system in the ECF or ICF? - Protein buffer system - Sulfate buffer system - Phosphate buffer system - Carbonic acid-bicarbonate buffer system

Sulfate buffer system

In a protein buffer system, if the pH increases, the carboxyl group of the amino acid dissociates and releases ______.

a hydrogen ion

define basic

a solution with a pH above 7; hydroxide ions predominate

define acidic

a solution with a pH below 7; hydrogen ions predominate

define neutral

a solution with a pH of 7; the solution contains equal numbers of hydrogen ions and hydroxide ions

define acid

a substance that dissociates to release hydrogens ions, decreasing pH

define base

a substance that dissociates to release hydroxide ions or accept hydrogen ions, increasing pH

Which of the following is a volatile acid and is a product of the combination of carbon dioxide and water?

carbonic acid

Deviations outside of the normal pH range due to increases in hydrogen ion concentrations would do all of the following except ______. - decrease the rate of respiration - disrupt the stability of cell membranes - change the activities of important enzymes - alter protein structure

decrease the rate of respiration

The primary role of the carbonic acid-bicarbonate buffer system is to __________.

prevent changes in pH caused by metabolic and fixed acids in the ECF

Which of the following does not occur when the pH increases? - the carboxyl group can become a carboxylate in (-COO-), which adds to the overall negative charge of proteins - the carboxylate ion can act as a weak base and accept additional H ions - the carboxyl group (-COOH) of the amino acid can dissociate acting as a weak acid and releasing an H - The R groups of histidine and cysteine will donate H ions

the carboxylate ion can act as a weak base and accept additional H ions

define pH

the negative exponent of the hydrogen ion concentration

The hemoglobin buffer system helps prevent drastic alterations in pH when ______.

the plasma PCO2 is rising or falling

What is required for the body to be in acid-base balance?

the production of hydrogen ions is exactly offset by their loss

What is the best way of describing respiratory compensation?

A change in the respiratory rate that helps stabilize the pH of the ECF.

A pH below ______ or above ______ is not sustainable for life.

6.8; 7.7

What is the normal pH of the ECF?

7.35-7.45

Which of the following is not accurate regarding the generation of ammonia within kidney tubules? - Ammonia is toxic to cells and rapidly diffuses into tubular fluid where it reacts with hydrogen ions to form NH4 - Tubule cells use glutaminase to break down the amino acid glutamine, which creates either ammonium ions or ammonia as a product - Ammonium ions (NH4) are transported into the tubule lumen and are exchanged for Na in the tubular fluid - Ammonia is broken down by carbonic anhydrase to form ammonium ions

Ammonia is broken down by carbonic anhydrase to form ammonium ions

After a person consumes a meal, the levels of which ion rises in the blood in response to increased acid production in the stomach?

Bicarbonate

What is the term for a substance that opposes a change in pH in a solution and can either remove or replace hydrogen ions?

Buffer

Acidosis is a more common problem than alkalosis because many acids are the direct byproducts of metabolic reactions. Which of the following acids is not a metabolic acid? - Pyruvic acid - Carbonic acid - Ketone bodies - Lactic acid

Carbonic acid

Which buffer is the most important buffer in the extracellular fluid?

Carbonic acid-bicarbonate buffer

If the partial pressure of CO2 rises in the blood, which of the following happens? - a decrease in H+ concentration - a decrease in HCO3- concentration - an increase in pH - a decrease in pH

a decrease in pH

Which of the following is not consistent with rising CO2 levels? - additional H+ ions are produced - additional bicarbonate ions are produced - additional Na+ ions are released - blood pH decreases

additional Na+ ions are released

Why must tubular fluid in the nephron be buffered? - to keep H+ from diffusing back into the blood - to allow secretion of H+ to continue - to prevent the pH of the urine from becoming too low - all of the above

all of the above

Salt

an ionic compound consisting of a cation other than hydrogen and an anion other than a hydroxide ion

Severe acidosis can be deadly for all of the following reasons except __________. - peripheral vasodilation produces a dramatic decrease in blood pressure, potentially producing circulatory collapse - central nervous system function deteriorates and the person becomes comatose - cardiac contractions grow weak and irregular and signs of heart failure may develop - hyperventilation leading to a lack of oxygen to critical tissues

hyperventilation leading to a lack of oxygen to critical tissues

Blood pH is normally between ______.

pH 7.35-7.45