Fluid Balance and Renal Physiology

Body water is divided into two major compartments:

A. Plasma and lymph
B. Intracellular fluid and extracellular fluid
C. Blood and interstitial fluid
D. Cytoplasm and plasma

B. Intracellular fluid and extracellular fluid

Approximately what fraction of total body water is intracellular fluid (ICF)?

A. 1/3
B. 1/2
C. 2/3
D. 3/4

C. 2/3

Extracellular fluid (ECF) accounts for approximately:

A. 1/3 of total body water
B. 2/3 of total body water
C. 90% of total body water
D. 10% of total body water

A. 1/3 of total body water

The two subdivisions of ECF are:

A. Plasma and cytoplasm
B. Plasma and interstitial fluid
C. Interstitial fluid and ICF
D. Lymph and cytoplasm

B. Plasma and interstitial fluid

Plasma makes up approximately what fraction of ECF?

A. 1/5
B. 2/5
C. 3/5
D. 4/5

A. 1/5

Interstitial fluid makes up approximately what fraction of ECF?

A. 1/5
B. 2/5
C. 3/5
D. 4/5

D. 4/5

The major extracellular cation is:

A. Potassium
B. Calcium
C. Sodium
D. Magnesium

C. Sodium

The major intracellular cation is:

A. Sodium
B. Potassium
C. Calcium
D. Chloride

B. Potassium

The unequal distribution of Na+ and K+ is primarily maintained by the:

A. Calcium pump
B. Sodium-potassium ATPase pump
C. Proton pump
D. Chloride pump

B. Sodium-potassium ATPase pump

The major extracellular anion is:

A. Phosphate
B. Protein
C. Chloride
D. Potassium

C. Chloride

Major intracellular anions include:

A. Phosphate and proteins
B. Sodium and chloride
C. Calcium and bicarbonate
D. Potassium and sodium

A. Phosphate and proteins

Plasma differs from interstitial fluid mainly because plasma contains:

A. More sodium
B. More potassium
C. Plasma proteins
D. More chloride

C. Plasma proteins

Hydrostatic pressure within capillaries tends to move fluid:

A. Into capillaries
B. Out of capillaries
C. Into cells
D. Into lymphatics only

B. Out of capillaries

Plasma colloid osmotic pressure tends to move fluid:

A. Out of capillaries
B. Into capillaries
C. Into cells
D. Into lymphatics

B. Into capillaries

Another name for plasma colloid osmotic pressure is:

A. Hydrostatic pressure
B. Filtration pressure
C. Oncotic pressure
D. Diffusion pressure

C. Oncotic pressure

The major force causing water movement between ICF and ECF is:

A. Hydrostatic pressure
B. Osmosis
C. Active transport
D. Filtration

B. Osmosis

Regulation of ECF volume is primarily dependent on:

A. Potassium balance
B. Protein balance
C. Salt balance
D. Calcium balance

C. Salt balance

Regulation of ECF osmolarity is primarily dependent on:

A. Water balance
B. Sodium balance
C. Protein balance
D. Calcium balance

A. Water balance

Osmolality is expressed as:

A. Osmoles/L of solution
B. Osmoles/kg of water
C. mmol/L plasma
D. g/L solution

B. Osmoles/kg of water

Osmolarity is expressed as:

A. Osmoles/kg water
B. Osmoles/L solution
C. g/L plasma
D. mg/dL

B. Osmoles/L solution

Normal body fluid osmolarity is approximately:

A. 100 mOsm/L
B. 200 mOsm/L
C. 300 mOsm/L
D. 500 mOsm/L

C. 300 mOsm/L

Adding an isotonic solution to ECF causes:

A. Increased ICF volume
B. No change in ECF volume
C. Increased ECF volume only
D. Decreased ECF volume

C. Increased ECF volume only

When isotonic saline is added to ECF:

A. Water enters cells
B. Water leaves cells
C. No net osmosis occurs
D. Cells shrink

C. No net osmosis occurs

Adding a hypertonic solution to ECF causes:

A. Water to move into cells
B. Water to move out of cells
C. No water movement
D. Cell swelling only

B. Water to move out of cells

A hypertonic ECF results in:

A. Increased intracellular volume
B. Decreased intracellular volume
C. No change in cell volume
D. Cell rupture

B. Decreased intracellular volume

Adding a hypotonic solution to ECF causes:

A. Water to move into cells
B. Water to move out of cells
C. No osmotic movement
D. Cell shrinkage

A. Water to move into cells

Hypotonic ECF causes cells to:

A. Shrink
B. Swell
C. Remain unchanged
D. Dehydrate

B. Swell

Hypertonicity of ECF is usually associated with:

A. Overhydration
B. Dehydration
C. Hypercalcemia
D. Hyperproteinemia

B. Dehydration

A common cause of ECF hypertonicity is:

A. Excessive water intake
B. Renal failure only
C. Excessive water loss
D. Excessive protein intake

C. Excessive water loss

Brain cells exposed to hypertonic ECF tend to:

A. Swell
B. Shrink
C. Remain unchanged
D. Divide rapidly

B. Shrink

Severe hypertonicity may lead to:

A. Improved cognition
B. Delirium, convulsions, or coma
C. Increased RBC production
D. Hypoglycemia

B. Delirium, convulsions, or coma

Hypotonicity of ECF is commonly associated with:

A. Dehydration
B. Overhydration
C. Hypernatremia
D. Hypovolemia

B. Overhydration

Patients with renal failure may develop hypotonicity because they:

A. Excrete too much dilute urine
B. Cannot excrete dilute urine effectively
C. Produce excess ADH only
D. Produce excess RBCs

B. Cannot excrete dilute urine effectively

In hypotonic ECF, water moves:

A. From cells to ECF
B. From ECF to cells
C. Into plasma only
D. Into lymphatics

B. From ECF to cells

Brain cell swelling may cause:

A. Confusion and headache
B. Increased alertness
C. Hypertension only
D. Polycythemia

A. Confusion and headache

The three major functions of the kidney include:

A. Digestion, absorption, secretion
B. Filtration/excretion, homeostasis, endocrine function
C. Respiration, circulation, metabolism
D. Hormone production only

B. Filtration/excretion, homeostasis, endocrine function

Which waste product is normally excreted by the kidneys?

A. Hemoglobin only
B. Urea
C. Collagen
D. Insulin

B. Urea

Regulation of acid-base balance is a function of the:

A. Liver
B. Heart
C. Kidney
D. Spleen

C. Kidney

Renin is important for regulation of:

A. RBC production
B. Blood pressure
C. Calcium absorption
D. Digestion

B. Blood pressure

Erythropoietin stimulates:

A. Platelet production
B. RBC production
C. WBC production
D. Plasma protein production

B. RBC production

Activation of vitamin D by the kidney helps regulate:

A. Sodium only
B. Potassium only
C. Calcium and phosphorus
D. Chloride only

C. Calcium and phosphorus

The functional unit of the kidney is the:

A. Glomerulus
B. Nephron
C. Loop of Henle
D. Bowman’s capsule

B. Nephron

Which nephron type has glomeruli in the outer cortex?

A. Juxtamedullary nephron
B. Cortical nephron
C. Collecting nephron
D. Medullary nephron

B. Cortical nephron

Which nephron type has long loops of Henle?

A. Cortical nephron
B. Juxtamedullary nephron
C. Proximal nephron
D. Distal nephron

B. Juxtamedullary nephron

The vasa recta are associated with:

A. Cortical nephrons
B. Juxtamedullary nephrons
C. Collecting ducts
D. Glomeruli only

B. Juxtamedullary nephrons

Juxtamedullary nephrons are especially important for:

A. Protein synthesis
B. Urine concentration
C. RBC production
D. Hormone metabolism

B. Urine concentration

The three basic renal processes are:

A. Filtration, absorption, secretion
B. Filtration, reabsorption, secretion
C. Filtration, diffusion, excretion
D. Absorption, secretion, metabolism

B. Filtration, reabsorption, secretion

Glomerular filtration occurs from:

A. Tubule to blood
B. Blood to Bowman’s capsule
C. Blood to urine directly
D. Cells to plasma

B. Blood to Bowman’s capsule

Normally filtered fluid is essentially:

A. Protein-rich plasma
B. Protein-free plasma filtrate
C. Whole blood
D. Pure water

B. Protein-free plasma filtrate

Which substances normally do NOT enter the filtrate?

A. Water and glucose
B. Sodium and chloride
C. Blood cells and plasma proteins
D. Urea and creatinine

C. Blood cells and plasma proteins

Tubular reabsorption moves substances from:

A. Blood to tubule
B. Tubule to blood
C. Tubule to bladder
D. Cells to urine

B. Tubule to blood

Approximately what percentage of filtrate is reabsorbed?

A. 50%
B. 75%
C. 90%
D. 99%

D. 99%

Tubular secretion moves substances from:

A. Tubule to blood
B. Blood to tubule
C. Bladder to tubule
D. Cells to lymph

B. Blood to tubule

Tubular secretion is important for:

A. Rapid elimination of substances
B. RBC production
C. Protein synthesis
D. Glucose formation

A. Rapid elimination of substances

ADH primarily regulates:

A. Calcium balance
B. Water balance
C. RBC production
D. Protein synthesis

B. Water balance

Hydration status is strongly influenced by:

A. ADH activity
B. Erythropoietin
C. Vitamin D only
D. Bile production

A. ADH activity

The juxtaglomerular apparatus plays a key role in:

A. Blood pressure regulation
B. RBC destruction
C. Protein synthesis
D. Digestion

A. Blood pressure regulation

Which hormone is released by juxtaglomerular cells?

A. ADH
B. Aldosterone
C. Renin
D. Erythropoietin

C. Renin

The loop of Henle is especially important in:

A. Concentrating urine
B. Producing RBCs
C. Producing plasma proteins
D. Digestion

A. Concentrating urine

The kidney maintains homeostasis by regulating:

A. Water, electrolytes, and acid-base balance
B. Digestion only
C. Oxygen transport only
D. Bone formation only

A. Water, electrolytes, and acid-base balance