Chap 26: Fluid, Electrolyte and Acid-Base Balance

Under normal circumstances, most water is lost in __________.

insensible losses via skin and lungs
What solute in body fluids determines most of their chemical and physical reactions?

The role of ADH is to __________.

produce dilute urine
decrease water reabsorption
increase water reabsorption
lower blood pressure
increase water reabsorption
The body's water volume is closely tied to a powerful water "magnet." What magnet is referred to here?
ionic sodium
Which of the following is NOT a hormone involved in water and electrolyte balance?

atrial natriuretic peptide
A decrease in blood CO2 levels leads to __________.

an increase in carbonic acid
an increase in blood pH
a drop in blood pH
an increased respiratory rate
an increase in blood pH
The most common cause of acid-base imbalance is __________.

metabolic acidosis
respiratory acidosis
metabolic alkalosis
respiratory alkalosis
respiratory acidosis
Which buffer system is the most abundant in the body?

carbonic acid-bicarbonate
What is the effect of hyperventilation on pH?
respiratory alkalosis
Which age group most commonly has fluid, electrolyte, and acid-base balance issues?

young adults
growing children
the elderly
Hypersecretion of aldosterone results in hypokalemia, which causes hyperpolarization of neurons; this in turn results in ______.
the need for a stronger than normal stimulus in order to trigger an action potential

(To trigger an action potential cells must reach threshold (critical electrical value required to open voltage-gated ion channels). If the membrane potential is hyperpolarized and falls below normal resting membrane potential, then more cations must enter the cytoplasm for the cell to reach threshold.)
the only logical explanation for why hypocalcemia increases neuromuscular excitability and causes muscle tetany?
Low plasma calcium ion concentration increases the permeability of neuron membranes to sodium ions, thereby causing depolarization that in turn increases the likelihood of action potentials being generated.

(Sodium and calcium are cations, and so loss of positive charge in the extracellular fluid would increase membrane permeability to all cations, including sodium. Recall that the efflux (outward movement) of sodium causes depolarization.)
Of the three buffer systems in the body, which is the strongest?

respiratory system
chemical buffer system
renal system
renal system

(Yes, although slow, the renal system is the strongest buffering system in the body. By altering the reabsorption and excretion of hydrogen ions and bicarbonate ions, the kidneys control the pH of body fluids.)
The bicarbonate buffer system is one of the chemical buffer systems of the body. How would the bicarbonate buffer system work if sodium hydroxide were added to a solution?
A hydrogen on carbonic acid would dissociate and join the hydroxyl group on the base to form water and sodium bicarbonate.

(Yes, a strong base (sodium hydroxide) would be converted to a weak base (sodium bicarbonate).)
The respiratory system is one of the three systems that regulate acid-base balance in the body. How does it work to decrease an acidosis?
Carbonic acid is broken down into water and CO2; the CO2 is then exhaled.

(Yes, CO2 can be blown off, thus decreasing acidity.)
In a respiratory acidosis the kidney would do?
he kidney would reabsorb bicarbonate and secrete hydrogen ions.

(Yes, when the kidney secretes hydrogen ions it also generates a bicarbonate ion, which further aids in decreasing the acidity of the plasma.)
Ingesting too much antacid would cause which of the following acid-base disturbances?

metabolic alkalosis
metabolic acidosis
respiratory acidosis
respiratory alkalosis
metabolic alkalosis

(Yes, ingestion of an antacid would increase the bicarbonate, causing a metabolic alkalosis.)
Vomiting will cause which type of acid-base disturbance?
metabolic alkalosis

(Yes, loss of HCL acid from the stomach would cause a metabolic alkalosis.)
Severe anxiety would cause which type of acid-base disturbance? What would be the compensation?
respiratory alkalosis; kidneys would excrete HCO3

(Yes, during hyperventilation caused by severe anxiety, carbonic acid is excreted from the lungs in the form of CO2, thus causing an alkalosis. Kidneys would compensate by excreting HCO3.)
Atrial natriuretic peptide is a hormone that is made in the atria of the heart. The influence of this hormone is to ________.
reduce blood pressure and blood volume by inhibiting sodium and water retention
Which of the following is not a trigger for juxtaglomerular granular cells to release renin?

decreased filtrate NaCl concentration
increased extracellular fluid water levels
sympathetic stimulation
decreased stretch due to decreased bp
increased extracellular fluid water levels
Which of the following would NOT be expected to lead to edema?

incompetent venous valves