Chapter 25 - Fluid, Electrolyte, Acid-Base Balance

What is consistent with rising CO2 levels?

- Additional H+ ions are produced. - Blood pH decreases. - Additional bicarbonate ions are produced.

Which are responses in the regulation of acute respiratory acidosis?

- Buffer systems other than the carbonic acid-bicarbonate system accept H+. - Increased respiratory rate - H+ ions are secreted into the urine.

cause of hyperkalemia

- Chronically low blood pH - Kidney damage or disease - Some diuretics

What is the normal pH of ECF?

7.35−7.45

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

Decrease in the production of ADH

Which of the following electrolytes is absorbed along the digestive tract via active transport only?

Fe2+ Submit

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

Greater water content of muscle tissue versus adipose tissue

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

Hypernatremia

Important homeostatic adjustments occur in response to changes in __________.

plasma volume or osmolarity

Which of the bulk minerals has the highest recommended dietary allowance (RDA), at 4700 mg?

potassium

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

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

respiratory acidosis

A loss of bicarbonate ions can lead to ____________________.

metabolic acidosis

Hyperventilation causes

respiratory alkalosis

Which statement is true regarding fluid balance in the digestive tract?

All the water movement in the digestive tract involves passive water flow down osmotic gradients.

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?

Carbonic acid

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

Carbonic acid-bicarbonate buffer

Which of the following is NOT a cause of hyperkalemia?

Decreased blood volume

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

Electrolytes

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?

HCO3- ions are secreted into the urine.

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.

Which of the following is not consistent with rising CO2 levels?

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.

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

Hypokalemia

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

Increased respiratory rate

Choose the correct statement regarding the relationship between water balance and sodium balance.

Increased sodium concentrations in the ECF will increase the movement of water from the ICF to the ECF. Submit

ADH secretion

Increases water reabsorption into the plasma

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

Choose the correct statement pertaining to acid-base disorders.

Metabolic acid-base disorders result from the production or loss of excessive amounts of fixed acids or organic acids.

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

Metabolic acidosis

Cotransport is a mechanism of absorption for which of the following electrolytes?

Na+

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?

Nutrient balance

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

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 elctrolytes 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 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.

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?

The respiratory rate is increased.

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.

Which of the following is NOT a basic principle for understanding fluid and electrolyte balance?

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

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

a hydrogen ion

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

salt

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

Metabolic acids __________.

are acid participants in, or by-products of, cellular metabolism

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

carbonic acid

Which of the following is an example of a volatile acid?

carbonic acid

Angiotensin II produces a coordinated elevation in the extracellular fluid volume by all of the following mechanisms except __________.

causing the release of ADH

Which trace mineral is significant as a cofactor for transaminations?

cobalt

Extracellular fluids in the body consist of all of the following except __________.

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

Protein buffer systems:

depend on the ability of amino acids to respond to pH changes by accepting or releasing H+.

Dehydration

develops when ECF water is lost, but electrolytes are retained

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

diffusion and active transport

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 _______________.

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

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

overall osmotic concentration

Blood pH is normally between __________.

pH 7.35−7.45

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

respiratory acid−base disorder

Which ionic compound is described as consisting of a cation other than a hydrogen ion and an anion other than a hydroxide ion?

salt

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

the plasma PCO2 is rising or falling

In the renal response to metabolic acidosis:

the renal tubule cells increase the concentration of bicarbonate ions in the ECF by reabsorbing CO2 from the tubular fluid. Submit

Which trace mineral functions as a cofactor of enzyme systems, notably carbonic anhydrase?

zinc

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

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

- Drinking a large volume of water - Excessive sweating - Diarrhea

What are responses during the regulation of metabolic alkalosis?

- HCO3- ions are secreted. - Buffer systems other than carbonic acid-bicarbonate donate H+. - H+ ions are generated.

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?

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

Why must tubular fluid in the nephron be buffered?

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

Renin is released in response to all of the following

- a decrease in the osmotic concentration of tubular fluid at the distal convouluted tubule - a decrease in plasma volume of blood pressure at the juxtaglomerular complex of the nephron - a decrease in Na+ concentration in the renal circulation

Severe acidosis (blood pH below 7.0) can be deadly for all of the following reasons

- central nervous system function deteriorates and the person become comatose - peripheral vasodilation produces a dramatic decrease in blood pressure, potentaily producing circulatory collapse - cardiac contractions grow weak and irregular and signs of heart failure may develop

ECF (extracellular fluid)

- fluid found outside the cells of the body, constitutes approximately about one third of total body fluid, - transporter of oxygen, nutrients, and waste products - includes: intravascular fluid, interstitial fluid, transcellular fluid

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

6.8; 7.7

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

A decrease in pH

Which statement regarding potassium balance is correct?

A key factor in the maintenance of potassium balance is the rate of potassium entry across the digestive epithelium.

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 occurs when an individual loses body water?

Plasma volume decreases, and electrolyte concentrations rise.

Which is the most abundant cation in the ICF?

Potassium

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

Proteins

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

Proteins > lipids > minerals > carbohydrates

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

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

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

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

The body content of water will rise if __________.

intake exceeds outflow

Which of the following is NOT an ECF?

intracellular fluid

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

The lowest amount of daily water loss occurs through which of the following methods of elimination?

loss in feces