Modules 25-Fluid_Electrolyte and Acid-Base Balance
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 buffer is the most important buffer in the extracellular fluid?
Carbonic acid-bicarbonate buffer
Which of the following would not be associated with a sensation of increased thirst?
Decrease in the production of ADH
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
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
Chronic diarrhea causes a severe loss of bicarbonate ions, resulting in __________.
metabolic acidosis
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
Given the following data, what would be your diagnosis for this patient? Data: pH 7.32; PCO2 38; HCO3- 20 mEq/L
Metabolic acidosis
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 is NOT a basic principle for understanding fluid and electrolyte balance?
Water moves into and out of cells by active transport.
Angiotensin II produces a coordinated elevation in the extracellular fluid volume by all of the following mechanisms except __________.
causing the release of ADH
When the amount of water you gain each day is equal to the amount you lose to the environment, you are in __________.
fluid balance
Blood pH is normally between __________.
pH 7.35−7.45
Hyperventilation causes __________.
respiratory alkalosis
Which of the following is not consistent with rising CO2 levels?
Additional Na+ ions are released.
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 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
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 principal ions in the extracellular fluid (ECF)?
Sodium, chloride, and bicarbonate
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.
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
Sodium ions enter the ECF by crossing the digestive epithelium via __________.
diffusion and active transport
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
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 hemoglobin buffer system helps prevent drastic alterations in pH when __________.
the plasma PCO2 is rising or falling
A pH below ____ or above _____ is not sustainable for life.
6.8; 7.7
What is the normal pH of ECF?
7.35−7.45
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 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 a cause of a fluid shift?
All of the listed choices are causes of a fluid shift.
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?
All of the listed choices are correct.
Why must tubular fluid in the nephron be buffered?
All of the listed choices are correct.
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 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 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
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
Which of the following occurs when an individual loses body water?
Plasma volume decreases, and electrolyte concentrations rise.
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
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.
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
All of the homeostatic mechanisms that monitor and adjust the composition of body fluids respond to changes in the __________.
extracellular fluid
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
The body content of water will rise if __________.
intake exceeds outflow
A loss of H+ or a gain in HCO3- can lead to _________.
metabolic alkalosis
Prolonged vomiting and loss of stomach acid causes __________.
metabolic alkalosis
Fluid and electrolyte balance is maintained by receptors that directly measure _________.
overall osmotic concentration
A mismatch between carbon dioxide generation in peripheral tissues and carbon dioxide excretion at the lungs is a __________.
respiratory acid−base disorder
Which is the most abundant cation in the ICF?
Potassium
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.
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
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
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
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 response during the regulation of metabolic alkalosis?
The respiratory rate is increased.
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
