Ch. 24 Fluid, Electrolyte, and Acid-Base Balance

Blood plasma osmolarity is higher than intracellular fluid osmolarity.

false

Ina state of fluid balance, average daily fluid gains and losses are equal.

true

Fluid intake is governed mainly by hypothalamic receptors called osmoreceptors.

true

1. The kidneys secrete ADH in response to dehydration.

false

Hypovolemia refers to a reduction in total body water while maintaining normal osmolarity.

true

1. Aldosterone promotes potassium excretion.

true

1. Natriuretic peptides promote sodium and potassium excretion.

false

Hyponatremia is usually a result of hypotonic hydration.

true

Hypocalcemia causes muscle weakness, whereas hypercalcemia causes potentially fatal muscle tetanus.

false

Chloride homeostasis is regulated as a side effect of sodium homeostasis.

true

A buffer system converts a weak acid or base into a strong one.

false

The three physiological buffer systems are urinary, digestive, and respiratory.

false

The kidneys neutralize more acid or base than any other buffer system.

true

1. Acidosis is a pH lower than 7, whereas alkalosis is a pH higher than 7.

false

Uncompensated alkalosis is a pH imbalance that can only be corrected with clinical intervention.

true

Where is the greatest volume of water in the body found?

A. Blood plasma and lymph
B. Intracellular fluid (ICF)
C. Transcellular fluid
D. Extracellular fluid (ECF)
E. Tissue (interstitial) fluid

Intracellular fluid (ICF)

What determines osmosis from one fluid compartment to another?

A. The temperature difference between compartments
B. The relative size of each compartment
C. The relative volume in each compartment
D. The relative concentration of solutes in each compartment
E. The blood pressure

The relative concentration of solutes in each compartment

In which compartment would fluid accumulate in edema?

A. Blood plasma
B. Lymph
C. Intracellular fluid
D. Tissue (interstitial) fluid
E. Transcellular fluid

Tissue (interstitial) fluid

Most body water intake is from ________, whereas most body water lost is via ________.

A. drinking; cutaneous transpiration and expired air
B. metabolic water; sweat
C. drinking; radiation
D. metabolic water; cutaneous transpiration
E. drinking; urine

drinking, urine

Fluid intake is governed mainly by hypothalamic neurons called __________.

A. baroreceptors
B. nociceptors
C. proprioceptors
D. osmoreceptors
E. mechanoreceptors

osmoreceptors

What is the function of antidiuretic hormone?

A. It inhibits salivation and thirst.
B. It stimulates hypothalamic osmoreceptors.
C. It stimulates angiotensin II secretion.
D. It promotes water conservation.
E. It targets the cerebral cortex.

It promotes water conservation.

Water output is largely controlled by varying ___________.

A. drinking
B. metabolic water production
C. urine volume
D. sweating
E. cutaneous transpiration

urine volume

Which of the following occurs when blood volume and pressure become too high?

A. ADH release is inhibited.
B. ADH release is stimulated.
C. The renal tubules reabsorb more water.
D. Therenal tubules reabsorb more sodium.
E. The kidneys produce less urine.

ADH release is inhibited.

Which of the following can prolonged exposure to cold weather lead to?

A. Increased sensible water loss
B. Increased respiratory water loss
C. Fluid sequestration in the upper limbs
D. Hypotonic hydration
E. Hypervolemia

increased respiratory water loss

In response to dehydration, osmoreceptors stimulate the secretion of __________.

A. bicarbonate ions
B. ANP
C. calcitonin
D. Sodium ions
E. ADH

ADH

26. A hemorrhage results in which of the following?

A decrease in water volume without significantly affecting the osmolarity

Long-term inhibition of thirst is mostly associated with which of the following?

A. Cooling of the mouth
B. A drop in blood osmolarity
C. Distension of the stomach by ingested water
D. Moistening of the mouth
E. Increased salivation

A drop in blood osmolarity

What is the principal cation of the ECF?

A. Ca2+
B. Cl-
C. Pi
D. Na+
E. K+

Na+

Where are cells with aldosterone receptors found?

A. Proximal convoluted tubule
B. Distal convoluted tubule
C. Posterior pituitary
D. Adrenal cortex
E. Adrenal medulla

Distal convolute tubule

What is the function of aldosterone?

A. It increases Na+ reabsorption and K+ secretion.
B. It increases both Na+ and K+ reabsorption.
C. It causes the urine to be more diluted.
D. It increases both Na+ and K+ secretion.
E. It reduces Na+ reabsorption and K+ secretion.

It increases Na+ reabsorption and K+secretion.

Hypernatremia is a plasma ___ concentration above normal.

A. Ca2+
B. Na+
C. K+
D. Cl-
E. Pi

Na+

Which of the following is not caused by hypernatremia?

A. A reduction in plasma volume
B. Edema
C. Interstitial fluid accumulation
D. Water retention
E. Hypertension

A reduction in plasma volume

What is the most significant solute in determining the distribution of water among fluid compartments?

A. Na+
B. Cl-
C. Ca2+
D. K+
E. Pi

Na+

Which of the following does not stimulate aldosterone secretion?


A. High blood potassium concentration
B. Hyponatremia
C. Hyperkalemia
D. High blood sodium concentration
E. Hypotension

High blood sodium concentration

Women have a tendency to retain water during part of the menstrual cycle because estrogen mimics the action of?

A. ADH.
B. aldosterone.
C. natriuretic peptide
D. oxytocin.
E. prolactin.

aldosterone

What is the most abundant cation in the ICF?

A. Pi
B. K+
C. Cl-
D. Ca2+
E. Na+

K+

What is the total body water (TBW) content of a 70kg young male?

40L

28. What is the greatest determinant of the intracellular water volume?
    
    A. Cl-
    B. K+
    C. Na+
    D. Ca2+
    E. PO43-

K+

Which of these conditions is not a result of hyperkalemia?

A. The resting membrane potential is more negative.
B. The cells are more sensitive to stimulation.
C. There is less diffusion of potassium out of the cells.
D. The cells are partially depolarized.
E. Cells are more excitable.

The resting membrane potential is more negative.

Which of the following occurs with hypokalemia?

A. Cells are partially depolarized.
B. Cells are hyperpolarized.
C. Cells are more excitable.
D. There is more diffusion of potassium into the cells.
E. The resting membrane potential is more positive.

Cells are hyperpolarized.

Hypokalemia can result from all of the following except from

A. chronic vomiting.
B. diarrhea.
C. heavy sweating.
D. aldosterone hyposecretion.
E. excessive use of laxatives.

aldosterone hyposecretion

What is the most abundant anion in the ECF?

A. H2PO4-
B. Cl-
C. HCO3-
D. HPO42-
E. PO43-

Cl-

Chloride homeostasis is achieved mainly as a result of ________homeostasis.

Na+

Which of the following is not a role of calcium in the body?

A. It is a significant component of nucleic acids.
B. It is important in blood clotting.
C. It participates in muscle contraction.
D. It activates exocytosis.
E. They serve as second messengers.

It is a significant component of nucleic acids.

How is calcium concentration in the body regulated?


A. By the parasympathetic nervous system
B. By hormones
C. By the sympathetic nervous system
D. By chloride and phosphate concentrations in the
plasma
E. By sodium and calcium concentrations in the plasma

by hormones

Which of the following accurately describes the inorganic phosphates(Pi)of the body fluids?

They participate in the activation of some enzymes.

Which of the following is a result of phosphate excretion from the body?

A. An increase of free chloride ions in the ECF
B. An decrease in free potassium ions in the ECF
C. An increase of free potassium ions in the ECF
D. An decrease in free calcium ions in the ECF
E. An increase in free calcium ions in the ECF

An increase in free calcium ions in the ECF

Which of the following represents the complete chemical reaction for the bicarbonate buffer system?

A. H2CO3 <-> HCO3- + H+
B. CO2 + H2O <-> HCO3- + H+
C. CO2 + H2O <-> H2CO3 <-> HCO3- + H+
D. H2CO3 <-> CO2 + H2O <-> HCO3- + H+
C. CO2 + H2O <-> HCO3- + H+ <-> H2CO3

CO2+ H2O= H2CO3HCO3-+ H+

What is the normal pH of tissue fluid?

7.35-7.45

What are the major chemical buffer systems of the body?

The bicarbonate, phosphate, and protein

What protein is the most important buffer in blood plasma?
A. fibrinogen
B. albumin
C. alpha globulins
D. gamma globulins
E. transferrin

Albumin

What protein is the most important buffer in erythrocytes?

A. Gamma globulin
B. Albumin
C. Hemoglobin
D. Fibrinogen
E. Myoglobin

Hemoglobin

Which of the following characterizes a weak base?

It binds a little H+and has a weak effect on pH.

When the renal tubules secrete hydrogen ions into the tubular fluid, they __________ at the same time.

A. secrete potassium
B. reabsorb potassium
C. secrete chloride
D. secrete sodium
E. reabsorb sodium

reabsorb sodium

Which buffer system accounts for 75% of all chemical buffering in the body fluids?

The protein buffer system

The bicarbonate buffer system would not work very well in the human body if not for the action of the respiratory system, which ___________.

A. supplies the buffer system with O2
B. supplies the buffer system with CO2
C.expels H+ produced by the buffer system
D. expels HCO3- produced by the buffer system
E. expels CO2 produced by the buffer system

expels CO2 produced by the buffer system

Which of the following describes an antiport system on the basal side of renal tubule cells?

It exchanges K+for Na+.

Proteins can buffer a drop in pH with their ___________ side groups and can buffer an increase in pH with their __________ side groups.

A. -NH2; -PO4
B. -PO4; -NH2
C. -PO4; -COOH
D. -NH2; -COOH
E. -COOH; -NH2

-NH2;-COOH

Acidosis has what effect on the resting membrane potential of nerve cells?

A. It causes depolarization above threshold
B. It causes repolarization
C. It causes depolarization below threshold
D. It causes hyperpolarization

it causes hyperpolarization.

How do the kidneys compensate respiratory acidosis?

A. By reabsorbing more hydrogen ions
B. By secreting more bicarbonate ions
C. By secreting more hydrogen ions
D. By secreting more sodium ions
E. By reabsorbing more ammonia

By secreting more hydrogen ions

Breathing into and out of a paper bag for along period of time will lead to _.

respiratory acidosis

An excessive intake of antacids can lead to which of the following?

A. Respiratory acidosis
B. Metabolic alkalosis
C. Respiratory alkalosis
D. Metabolic acidosis
E. Digestive alkalosis

Metabolic alkalosis

Chronic vomiting can lead to which of the following?

A. Metabolic alkalosis
B. Respiratory alkalosis
C. Respiratory acidosis
D. Metabolic acidosis
E. Lymphatic alkalosis

Metabolic alkalosis

Emphysema can lead to which of the following?

A. Respiratory alkalosis
B.Metabolic alkalosis
C. Metabolic acidosis
D. Respiratory acidosis
E. Digestive alkalosis

respiratory acidosis

A patient suffering from diabetic acidosis would display which of the following symptoms?

A. Hypoventilation
B. Decreased H+ secretion by the kidneys
C. Decreased ammonia secretion by the kidneys
D. Hyperventilation

hyperventilation