Fluid, Electrolyte, and Acid-base Balance

4. Extracellular fluids in the body consist of __________.

All of the listed responses are correct.

Protein buffer systems do NOT affect __________.

All of these substances are affected by protein buffers.

Which of the following is NOT one of the four basic concepts pertaining to fluid and electrolyte regulation?

Cells are able to move water by the process of active transport.

Which of the following is NOT a basic concept of fluid and electrolyte balance?

All homeostatic mechanisms respond to changes in the ICF.

Which of the following occurs when large amounts of pure water are consumed?

Osmolarities of the two compartments are slightly lower.

Chemoreceptors in the carotid and aortic bodies are sensitive to the __________ of circulating blood.

PCO2

In a protein buffer system, if the pH increases, the carboxyl group (COOH) of the amino acid dissociates and releases __________.

a hydrogen ion

As a result of the aging process, the ability to regulate pH through renal compensation changes as a result of __________.

a reduction in the number of functional nephrons

The elderly have an increased risk of respiratory acidosis because of __________.

a reduction in vital capacity

The concentration of potassium in the ECF is controlled by adjustments in the rate of active secretion __________.

along the distal convoluted tubule of the nephron

The most common problems with electrolyte balance are caused by __________.

an imbalance between sodium gains and losses

Under normal circumstances, during respiratory acidosis the chemoreceptors monitoring the PCO2 of the plasma and CSF will eliminate the problem by calling for __________.

an increase in pulmonary ventilation rates

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

bicarbonate

Sodium levels are figured as a balance between __________.

both absorption of sodium across the digestive epithelium and excretion at the kidney and other sites

Which of the following hormones play(s) a major role in mediating fluid AND electrolyte balance?

both atrial natriuretic peptide and aldosterone

The kidneys respond to respiratory acidosis by __________.

both by excreting hydrogen ions and by generating bicarbonate ions

Which of the following conditions could cause muscle cramps or spasms?

both hyperkalemia and hypocalcemia

The symptoms of low potassium (hypokalemia) include __________.

both muscle weakness and paralysis

The buffering system in the ICF is made up of __________.

both protein buffers and phosphate buffers

Frequent causes of metabolic acidosis include __________.

both severe kidney damage and poorly controlled diabetes mellitus

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

Abnormal levels of the hormones calcitriol, calcitonin, and parathyroid hormone would lead to an imbalance of which electrolyte?

calcium

Hypercalcemia

calcium concentrations of the ECF in excess of 5.3 mEq/L

Which of the following is NOT a fixed acid?

carbonic acid

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

carbonic acid

Which of the following is NOT one of the major buffer systems of the body?

chloride buffer system

Which of the following does NOT affect fluid levels in the blood?

chloride shift

The major anion in the extracellular fluid compartment is __________, whereas the major intracellular anion is __________.

chloride; biphosphate

What is the most frequent cause of respiratory acidosis?

chronic pulmonary disorders

Alcohol and barbiturate use could cause a desensitization of the respiratory centers, leading to __________.

chronic respiratory acidosis

Aldosterone

conserves sodium and increases sensitivity to salty tastes

Which of the following would NOT be associated with a sensation of increased thirst?

decrease in the production of ADH

The lungs respond to metabolic alkalosis by __________.

decreasing the respiratory rate

When water losses outpace water gains, __________ occurs.

dehydration

Sodium ions enter the ECF by crossing the digestive epithelium via __________.

diffusion and active transport

Angiotensin I and II

elevate systemic blood pressure, promote thirst, and stimulate the release of aldosterone and ADH

Metabolic alkalosis

elevated levels of bicarbonate ions in blood plasma

Interstitial fluid, plasma, and cerebrospinal fluid are all considered __________ fluid.

extracellular

All of the homeostatic mechanisms that monitor and adjust the composition of body fluids respond to changes in the __________.

extracellular fluid

When the amount of water you gain each day is equal to the amount you lose to the environment, you are in __________.

fluid balance

If the ECF is hypertonic with respect to the ICF, water will move __________.

from the cells into the ECF until osmotic equilibrium is restored

What is the term for an abnormally high concentration of sodium in the ECF?

hypernatremia

Respiratory alkalosis

hyperventilation that washes out the carbon dioxide in the blood, increasing the pH

What is the term for an abnormally low concentration of potassium in the ICF?

hypokalemia

When pure water is consumed, the extracellular fluid becomes __________.

hypotonic with respect to the ICF

Which of the following might be a response to respiratory acidosis?

increased respiratory rate

When a normal pulmonary response does NOT reverse respiratory acidosis, the kidneys respond by __________.

increasing the rate of hydrogen ion secretion into the filtrate

The exchange between plasma and interstitial fluid is determined by the relationship between the __________.

net hydrostatic and net colloid osmotic pressures

When water is lost but electrolytes are retained, the osmolarity of the ECF rises and osmosis then moves water __________.

out of the ICF and into the ECF until isotonicity is reached

Blood pH is normally measured at __________.

pH 7.35-7.45

Acidosis can cause all of the following EXCEPT __________.

peripheral vasoconstriction

Hypokalemia

plasma concentrations of potassium below 3.5 mEq/L

Important homeostatic adjustments occur in response to changes in __________.

plasma volume or osmolarity

Which is the most abundant cation in the ICF?

potassium

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

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

Metabolic acidosis

producing large quantities of metabolic acids (fixed or organic acids)

Which of the following will NOT cause metabolic acidosis?

production of hydrochloric acid in the stomach

A metabolic alkalosis can be due to __________.

prolonged vomiting

A metabolic alkalosis can occur as a result of __________.

prolonged vomiting

Atrial and brain natriuretic hormone

reduces thirst, lowers blood pressure and plasma volume

What are the two important effects of increased release of ADH?

reduction of urinary water losses and stimulation of the thirst center

Which of the following does NOT cause hypokalemia?

renal failure

A mismatch between carbon dioxide generation in peripheral tissues and carbon dioxide excretion at the lungs is a __________.

respiratory acid-base disorder

Hypercapnia, or an elevation of carbon dioxide in the blood, is a sign of __________.

respiratory acidosis

Hypoventilation causes __________.

respiratory acidosis

What is the most frequent challenge to acid-base equilibrium?

respiratory acidosis

Hyperventilation causes __________.

respiratory alkalosis

Which of the following is NOT a source of water gains?

sensible perspiration

Which is the most abundant cation in the ECF?

sodium

What are the major contributors to the osmolarities of the ECF and the ICF?

sodium and potassium

The most common problems with electrolyte balance are caused by an imbalance between gains and losses of __________.

sodium ions

Which of the following electrically charged substances (ions) are NOT primarily found in the intracellular fluid?

sodium ions

What are the principal ions in the extracellular fluid (ECF)?

sodium, chloride, and bicarbonate

The major cation in the extracellular fluid compartment is __________, whereas the major intracellular cation is __________.

sodium; potassium

Ketone bodies accumulate in the blood during conditions of __________.

starvation

Antidiuretic hormone

stimulates water conservation at the kidneys, and stimulates the thirst center

Which of the following is NOT a buffer system in the ECF or ICF?

sulfate buffer system

What are the most important buffers in the ECF?

the carbonic acid-bicarbonate buffer system

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

the plasma PCO2 is rising or falling

Which represents the largest volume of water lost each day under normal physiological conditions?

urine

Acute respiratory acidosis can occur in each of the following instances EXCEPT __________.

when normal respiratory function is compromised but compensatory mechanisms have not failed

Chronic diarrhea causes a severe loss of bicarbonate ions, resulting in __________.

metabolic acidosis

Prolonged vomiting and loss of stomach acid cause __________.

metabolic alkalosis

Prolonged vomiting can result in __________.

metabolic alkalosis

Acute respiratory acidosis

most common challenge to acid-base equilibrium, due to hypoventilation and increased CO2 concentrations

Normal ECF pH values are limited to the range between __________.

7.35 and 7.45

Atrial natriuretic peptide __________.

A. blocks aldosterone release B. reduces thirst C. blocks ADH release

Deviations outside of the normal pH range due to changes in hydrogen ion concentrations __________.

A. change the activities of important enzymes B. disrupt the stability of cell membranes C. alter protein structure

High concentrations of hydrogen ions in body tissues can __________.

A. disrupt cell membranes B. change the shape of complex molecules C. break chemical bonds

Disorders that have the potential for disrupting pH balance in the body include __________.

A. heart failure and hypotension B. neural damage and CNS disease C. emphysema and renal failure

The activity that occurs in the body to maintain calcium homeostasis occurs primarily in the __________.

A. kidneys B. bone C. digestive tract

Acidosis is a more common problem than alkalosis because many acids are by-products of metabolic reactions. Which of the following acids fits that description?

A. lactic acid B. carbonic acid C. sulfuric acid

The major causes of metabolic acidosis include which of the following?

A. production of a large number of fixed or organic acids B. impaired ability to excrete H+ at the kidneys C. a severe bicarbonate loss

Atrial natriuretic peptide hormone __________.

A. reduces thirst B. blocks the release of ADH C. blocks the release of aldosterone

Hypocapnia __________.

A. refers to low levels of carbon dioxide in the blood B. can be caused by hyperventilation, which can be used to counter respiratory acidosis C. is a self-correcting condition when caused by hyperventilation

Pulmonary and renal mechanisms support the buffer systems by __________.

A. secreting or generating hydrogen ions B. generating additional buffers when necessary C. controlling the excretion of acids and bases

Angiotensin II produces a coordinated elevation in the extracellular fluid volume by __________.

A. stimulating thirst B. causing the release of ADH C. triggering the secretion of aldosterone

Treatment for hyperkalemia includes the __________.

A. use of appropriate diuretics B. administration of buffers such as sodium bicarbonate C. infusion of hypotonic solution

Which of the following occurs when an individual loses body water?

Plasma volume decreases, and electrolyte concentrations rise.

Which of the following hormones causes the conservation of sodium in the kidneys?

aldosterone

Renin

activates angiotensin I

Which of the following is NOT a response to respiratory acidosis?

inhibition of arterial and CSF chemoreceptors

The body content of water or electrolytes will rise if __________.

intake exceeds outflow

Which of the following is NOT an ECF?

intracellular fluid

Potassium ions are found in the highest concentrations in which of the following fluid compartments?

intracellular fluid (ICF)

What is an electrolyte?

ions released through the dissociation of inorganic compounds

Whenever the rate of sodium intake or output changes, there is a corresponding gain or loss of water that tends to __________.

keep the sodium concentration constant

Which of the following body organs has the greatest measure of control over body fluid and composition levels?

kidneys

What is the most frequent cause of metabolic alkalosis?

loss of acids, especially through vomiting

Increasing or decreasing the rate of respiration can have a profound effect on the buffering capacity of body fluids by __________.

lowering or raising the PCO2

Respiratory alkalosis develops when respiratory activity __________.

lowers plasma PCO2 to below-normal levels