Chapter 27

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

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

Which component makes up the largest portion of the solid components in the body?

Proteins

Ketone bodies accumulate in the blood during are associated with __________.

starvation

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

the plasma PCO2 is rising or falling

The concentrations of the cations and anions in the ICR and ECF are meansured in terms of milliequivalents per liter (mEq/L). mEq/L represents the _________________.

total number of positive and negative electrical charges in a liter of solution

Which of the following accurately lists the solid components of the human body by weight from greatest to smallest?

Proteins > lipids > minerals > carbohydrates

A pH below ____ or above _____ is not sustainable for life.

6.8; 7.7

Which of the following is the best way of describing respiratory compensation?

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

If the partial pressure of CO2 rises in the blood, which of the following happens?

A decrease in pH

What effect does prolonged sweating have on sodium ion levels?

A loss of sodium ions from the ECF

Which of the following is true regarding antidiuretic hormone (ADH) and its role in regulating fluid and electrolyte balance?

ADH stimulates water conservation by the kidneys and helps to concentrate the urine.

Which of the following is not consistent with rising CO2 levels? Additional Na+ ions are released. Blood pH decreases. Additional bicarbonate ions are produced. Additional H+ ions are produced.

Additional Na+ ions are released.

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

Aldosterone

Which of the following accurately describes the role of aldosterone in fluid and electrolyte balance?

Aldosterone is secreted in response to an increasing K+ or decreasing Na+ level in the blood.

Which of the following is not accurate regarding the generation of ammonia within kidney tubules? Ammonium ions (NH4+) are transported into the tubule lumen and are exchanged for Na+ in the tubular fluid. Ammonia (NH3) is toxic to cells and rapidly diffuses into tubular fluid where it reacts with H+ to form NH4+. Ammonia is broken down by carbonic anhydrase to form ammonium ions. Tubule cells use glutaminase to break down the amino acid glutamine, which creates either ammonium ions or ammonia as a product.

Ammonia is broken down by carbonic anhydrase to form ammonium ions.

An abnormally high level of which electrolyte could be caused by hyperparathyroidism and would result in kidney stones, confusion, muscle pain, and cardiac arrhythmias?

Calcium

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?

Carbonic acid

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

Carbonic acid

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

Carbonic acid-bicarbonate buffer

Which of the following is NOT an ECF? Cerebrospinal fluid Lymph Intracellular fluid Plasma

Intracellular fluid

Which of the following would not be associated with a sensation of increased thirst? Increase in the production of ADH Increase in renin secretion Increase in the production of angiotensin II Decrease in the production of ADH

Decrease in the production of ADH

Which of the following is NOT a cause of hyperkalemia? Decreased blood volume Kidney damage or disease Some diuretics Chronically low blood pH

Decreased blood volume

What would be the response of the body to an increase in ECF volume if you were to drink a large quantity of a sports drink?

Decreased thirst Increased water and sodium loss in the urine Natriuretic peptides would be released by cardiac muscle cells.

Which of the following is a cause of a fluid shift?

Drinking a large volume of water Diarrhea Excessive sweating

Which of the following is not a hormone that mediates adjustments to fluid balance and electrolyte balance? BNP EPO Aldosterone ADH

EPO

Water, by far, is the biggest component of our body fluids. What is the second-largest component of our body fluids?

Electrolytes

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

Intracellular fluid (ICF)

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

Plasma volume decreases, and electrolyte concentrations rise.

Which is the most abundant cation in the ICF?

Potassium

Why is there a difference in the ICF percentages in males versus females?

Greater water content of muscle tissue versus adipose tissue

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.

Which of the following is NOT a response in the regulation of acute respiratory acidosis? H+ ions are secreted into the urine. HCO3- ions are secreted into the urine. Increased respiratory rate Buffer systems other than the carbonic acid-bicarbonate system accept H+.

HCO3- ions are secreted into the urine.

The major causes of metabolic acidosis include all of the following except? Production of a large number of fixed or metabolic acids Hypercapnia Impaired ability to excrete H+ at the kidneys A severe bicarbonate loss

Hypercapnia

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

Hypernatremia

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

Hypokalemia

A patient presents with a blood pH of 7.5, a PCO2 of 32, and a normal HCO3-. What is the likely cause of this patient's abnormal lab values?

Panic attacks causing acute respiratory alkalosis

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

Increased respiratory rate

What is an electrolyte?

Ions released through the dissociation of inorganic compounds

The loss of mineral content with age is frequently due to what cause?

Loss of muscle and bone mass

Which of the following is NOT a principal ion in the extracellular compartments? Magnesium ion (Mg2+) Bicarbonate (HCO3-) Sodium (Na+) Chloride (Cl-)

Magnesium ion (Mg2+)

In which of the following would water represent the highest percentage of body weight?

Male infant

Given the following data, what would be your diagnosis for this patient? Data: pH 7.32; PCO2 38; HCO3- 20 mEq/L

Metabolic acidosis

Homeostasis maintains a stable internal environment, composed of our body fluids. Which of the following is NOT one of the processes for stabilizing body fluid volumes? Acid-base balance Electrolyte balance Nutrient balance Fluid balance

Nutrient balance

Why is it more likely for an older person to become dehydrated?

Reduction in sensitivity to ADH and aldosterone with age Ability to concentrate the urine decreases with age. Water content is reduced with age.

Electrolyte balance requires matching the gain of electrolytes from your diet with the loss of electrolytes. Which of the following is NOT a way your body removes electrolytes?

Respiration

Which of the following descriptions is correct?

Respiratory acid-base disorders result from a mismatch between CO2 generation in peripheral tissues and CO2 excretion by the lungs.

Given the following data, what would be your diagnosis for this patient? Data: pH 7.3; pCO2 51 mm Hg.; HCO3- 31 mEq/L

Respiratory acidosis

Which term is correctly matched up with its definition?

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

What would happen if you ate a large quantity of salty potato chips without drinking anything?

Secretion of ADH would increase.

What is the kidney's response to acidosis?

Secretion of H+ into urine

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

Sensible perspiration

Which is the most abundant cation in the ECF?

Sodium

Which of the following is NOT a principal ion in the intracellular compartment? Magnesium (Mg2+) Potassium (K+) Sodium (Na+) Phosphate (HPO42-)

Sodium (Na+)

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

Sodium, chloride, and bicarbonate

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

Sulfate buffer system

Which of the following is a basic principle in understanding fluid and electrolyte balance?

The body's content of water or electrolytes will increase if dietary gains exceed losses to the environment.

Which of the following does not occur when the pH increases (become more basic)? The R groups of histidine and cysteine will donate H+ ions. 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 aminio acid can dissociate acting as a weak acid and releasing an H+.

The carboxylate ion can act as a weak base and accept additional H+ ions.

What would be the effect on the osmotic concentration of blood plasma if you were in the desert without water for a day?

The osmotic concentration of your plasma would increase because of water leaving your body.

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

Urine

What is meant by the term metabolic water?

Water generated during oxidative phosphorylation

Which of the following is accurate regarding water content?

Water makes up about 60 percent of the total body weight of an adult male.

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

The production of hydrogen ions is exactly offset by their loss.

Which of the following is NOT a response during the regulation of metabolic alkalosis? Buffer systems other than carbonic acid-bicarbonate donate H+. The respiratory rate is increased. HCO3- ions are secreted. H+ ions are generated.

The respiratory rate is increased.

Why must tubular fluid in the nephron be buffered?

To keep H+ from diffusing back into the blood To prevent the pH of the urine from becoming too low To allow secretion of H+ to continue

Which of the following is NOT a basic principle for understanding fluid and electrolyte balance? No receptors exist for fluid and electrolyte balance. Water moves into and out of cells by active transport. Homeostatic mechanisms respond to changes in the ECF. Water and electrolyte content in the body is a balance between intake and losses.

Water moves into and out of cells by active transport.

Renin is released in response to all of the following except ____________. a decrease in K+ concentration in the renal circulation a decrease in the osmotic concentration of tubular fluid at the distal convouluted tubule a decrease in Na+ concentration in the renal circulation a decrease in plasma volume of blood pressure at the juxtaglomerular complex of the nephron

a decrease in K+ concentration in the renal circulation

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 due to __________.

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 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

Osmosis allows water to freely cross plasma membranes except in the _____________.

ascending limb of the nephron loop

Angiotensin II produces a coordinated elevation in the extracellular fluid volume by all of the following mechanisms except __________. causing the release of ADH decreasing sodium loss in urine stimulating thirst triggering the secretion of aldosterone

causing the release of ADH

Angiotensin II produces a coordinated elevation in the extracellular fluid volume by all of the following mechanisms except __________. triggering the secretion of aldosterone causing the release of ADH decreasing sodium loss in urine stimulating thirst

causing the release of ADH

Extracellular fluids in the body consist of all of the following except __________. aqueous humor cytosol cerebrospinal fluid lymph

cytosol

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

When water losses outpace water gains, __________ occurs.

dehydration

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

diffusion and active transport

A fluid shift of abnormally large amounts of water from the plasma into the interstitial fluid is called __________.

edema

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

Severe acidosis (blood pH below 7.0) can be deadly for all of the following reasons except _______________. cardiac contractions grow weak and irregular and signs of heart failure may develop peripheral vasodilation produces a dramatic decrease in blood pressure, potentaily producing circulatory collapse hyperventilation leading to a lack of oxygen to critical tissues central nervous system function deteriorates and the person become comatose

hyperventilation leading to a lack of oxygen to critical tissues

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

increasing the rate of hydrogen ion secretion into the tubular fluid

The body content of water will rise if __________.

intake exceeds outflow

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

A loss of bicarbonate ions can lead to ____________________.

metabolic acidosis

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

metabolic acidosis

A loss of H+ or a gain in HCO3- can lead to _________.

metabolic alkalosis

Prolonged vomiting and loss of stomach acid causes __________.

metabolic alkalosis

A effects of both respiratory acidosis and metabolic acidosis are especially serious in cases of ________.

near drowning

Fluid and electrolyte balance is maintained by receptors that directly measure _________.

overall osmotic concentration

Important homeostatic adjustments occur in response to changes in __________.

plasma volume or osmolarity

The p in pH refers to ______.

power

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

A metabolic alkalosis can be due to __________.

prolonged vomiting

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

respiratory acidosis

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

respiratory acid−base disorder

Hyperventilation causes __________.

respiratory alkalosis