Chapter 24

The total body water content of a 70kg (150 lb) young male is about

100L

125L

15L

40L

40L

Which represents the largest fluid compartment in the body?

Tissue (interstitial) fluid

Intracellular fluid

Blood plasma

Lymph

Intracellular Fluid

We typically gain and lose about______ mL of fluids a day

25ml

250ml

2500ml

25000ml.

2,500

Water is produced in ____ synthesis reactions

dehydration

Which term refers to water that is taken into the body in food and drink?

metabolic water

preformed water

secreted water

excreted water

preformed water

The water content (as a percentage of total body weight) of a 70 kg young male is which of the following?

Around 55 - 60% of total body weight

Less than that of obese and elderly people

The same as that of a newborn baby

Slightly less than that of an adult female

Around 55 - 60% of total body weight

About how much of body water is found in intracellular fluids?

8%

35%

2%

65%

65%

About how much of body water is found in intracellular fluids?

Hot weather

cold weather

cold weather

When is a person in a state of fluid balance?

Daily fluid losses are higher than gains.

Daily fluid gains are higher than losses.

Daily fluid gains equal losses.

Daily fluid gains equal losses.

Which best defines osmoreceptors?

Cortical neurons that produce a conscious sense of thirst

Hypothalamic neurons that respond to increased solute concentration in the extracellular fluid

Receptors in the afferent arteriole in the kidneys that detect changes in blood pressure

Receptors on the tongue that determine the salt content of food

Hypothalamic neurons that respond to increased solute concentration in the extracellular fluid

Which is produced as a by-product of dehydration synthesis reactions and aerobic respiration?

Urine

Transcellular fluid

Metabolic water

Interstitial fluid

Metabolic water

The only way to control water output significantly is through variations in urine volume.

True

False

True

Water intake totals about 2500 mL/day. The combination of water from food (about 700 mL) and drink (about 1600 mL) is known as ____ water

preformed

A newborn baby's weight is as much as 75% water, whereas obese and elderly people's weight is as little as 45% water.

True

False

True

Prolonged, heavy work increases which of the following?

Perspiration

Urine

Fecal moisture

Respiratory Loss

Perspiration, respiratory loss

Choose all that are types of fluid deficiency?

Hypotonic hydration

volume depletion

dehydration

thirst

Where are osmoreceptors found?

Skin

Bones

Hypothalamus

Muscles

Hypothalamus

Water output is primarily controlled through variations in which of the following?

Metabolic water production

Sweating

Cutaneous transpiration

Urine Volume

Urine Volume

Which may occur when proportionate amounts of water and sodium are lost without replacement, for example due to hemorrhage, chronic vomiting, or diarrhea?

Hypovolemia

Dehydration

Hypotonic hydration

Low osmolarity

Hypovolemia

Hypovolemia and dehydration are both examples of fluid deficiency. How do they differ?

In dehydration water is lost, and in hypovolemia both water and electrolytes are lost.

In hypovolemia only water is lost, and in dehydration both water and electrolytes are lost.

They differ only in the amount of fluid lost.

In dehydration only water is lost, and in hypovolemia only electrolytes are lost.

In dehydration water is lost, and in hypovolemia both water and electrolytes are lost.

What happens to ECF osmolarity during dehydration?

It increases

It remains the same.

It decreases

It increases

Hypovolemia

Total body water is reduced; ECF remains isotonic.

Dehydration

Total body water is reduced; ECF becomes hypertonic.

Volume excess

Total body water is elevated; ECF remains isotonic.

Hypotonic hydration

Total body water is elevated; ECF becomes hypotonic.

Sodium, potassium, calcium and hydrogen ions are examples of which of the following?

Cations

Which statement about dehydration is true?

Dehydration raises blood volume.

Dehydration raises blood osmolarity.

Dehydration increases salivation.

Dehydration raises blood osmolarity

In which form of fluid imbalance is total body water reduced and osmolarity elevated?

Dehydration (negative water balance)

Volume excess

Hypotonic hydration (positive water balance, water intoxication)

Hypovolemia (volume depletion)

Dehydration (negative water balance)

Which statement is correct regarding the relative abundance of electrolytes in the ECF and ICF?

Sodium and potassium are both more abundant in the ECF as compared to the ICF.

Sodium and potassium are both more abundant in the ICF as compared to the ECF.

Potassium is more abundant in the ECF and sodium is more abundant in the ICF.

Sodium is more abundant in the ECF and potassium is more abundant in the ICF.

Sodium is more abundant in the ECF and potassium is more abundant in the ICF.

Choose all that are important functions of sodium.

It is involved in generating body heat via the Na-K pump.

It is used as an important fuel source for cellular respiration.

It participates in cotransport of glucose, K+ and Ca+.

It participates in muscle and nerve depolarization.

It is involved in generating body heat via the Na-K pump.

It participates in cotransport of glucose, K+ and Ca+.

It participates in muscle and nerve depolarization.

ECF =

Sodium

Most intracellular magnesium is complexed with which of the following?

ATP

G proteins

Vitamin D

Calcium

ATP

ICF =

Potassium

Choose all that are important functions of phosphate ions.

Regulating metabolic pathways by activating and deactivating enzymes

Acting as a major charge carrier during action potentials

Helping to stabilize the pH of body fluids

Triggering muscle contraction and exocytosis

Acting as a major charge carrier during action potentials

Helping to stabilize the pH of body fluids

Regulating metabolic pathways by activating and deactivating enzymes

Which is true about enzymes?

Multiple choice question.

They only function at a pH of 7.

They function in a wide range of pHs.

They are very sensitive to pH.

They are very sensitive to pH.

Which statement is correct regarding the relative abundance of electrolytes in the ECF and ICF?

Multiple choice question.

Sodium is more abundant in the ECF and potassium is more abundant in the ICF.

Sodium and potassium are both more abundant in the ICF as compared to the ECF.

Sodium and potassium are both more abundant in the ECF as compared to the ICF.

Potassium is more abundant in the ECF and sodium is more abundant in the ICF.

Sodium is more abundant in the ECF and potassium is more abundant in the ICF.

HCl ionizes freely, gives up most of its hydrogen ions, and can markedly lower the pH of a solution. Because of this it is classified as which of the following?

Multiple choice question.

Strong base

Weak acid

Strong acid

Weak base

Strong acid

The pH of a solution is determined solely by the concentration of which ion?

Multiple choice question.

Phosphate

Sodium

Hydrogen

Bicarbonate

Hydrogen

Choose all that are important functions of phosphate ions.

Multiple select question.

Regulating metabolic pathways by activating and deactivating enzymes

Acting as a major charge carrier during action potentials

Triggering muscle contraction and exocytosis

Helping to stabilize the pH of body fluids

Regulating metabolic pathways by activating and deactivating enzymes

Helping to stabilize the pH of body fluids

Choose all the reasons it is important to maintain the pH of blood and tissue fluids within normal limits.

Multiple select question.

The structure and function of macromolecules are pH dependent.

Slight deviations from normal pH can shut down metabolic pathways.

Most enzymes require an acidic pH to function properly.

Hormones require a blood pH of at least 7.7 to function optimally.

The structure and function of macromolecules are pH dependent.

Slight deviations from normal pH can shut down metabolic pathways.

An acid such as hydrochloric acid (HCl) that ionizes freely, gives up most of its hydrogen ions, and can markedly lower the pH of a solution is known as what type of acid?

Multiple choice question.

Weak

Organic

Nucleic

Strong

Strong

H2CO3 ionizes only slightly and keeps most of its hydrogen in a chemically bound form that does not affect pH. Because of this it is classified as which of the following?

Multiple choice question.

Strong base

Weak acid

Strong acid

Weak acid

Which property of a solution is determined by the concentration of hydrogen ions?

Multiple choice question.

pH

Temperature

Osmolarity

Pressure

pH

Which is the best definition of a weak base?

Multiple choice question.

A base that binds lots of OH- and has a strong effect on pH

A base that binds little OH- and has a weak effect on pH

A base that lowers the pH

A base that binds only some of the available H+ and has relatively small effect on pH

A base that binds only some of the available H+ and has relatively small effect on pH

Which ion acts as an important buffer that helps stabilize the pH of body fluids?

Multiple choice question.

Magnesium

Potassium

Sodium

Phosphate

Phosphate

Slight deviations from the body's normal ____ range can shut down metabolic pathways as well as alter the structure and function of other macromolecules. Buffer systems help to avoid this.

pH

Which is an example of a strong acid?

Multiple choice question.

All monosaccharides

Hydrochloric acid

Carbonic acid

Hydrochloric acid

Which is an example of a weak acid?

Multiple choice question.

Sodium bicarbonate

Hydrochloric acid

Carbonic acid

Carbonic acid

As compared to hydroxide (OH-), bicarbonate (HCO3-) binds a relatively small amount of the available H+ and therefore has less of an effect on pH. Because of this, bicarbonate is classified as which of the following?

Multiple choice question.

Weak acid

Strong base

Strong acid

Weak base

Weak base

Phosphates are components of which of the following?

Multiple choice question.

Hydrochloric acid

Carbohydrates

DNA

DNA

A buffer can be generally defined as a mechanism that does which of the following?

Multiple choice question.

Catalyzes biological reactions

Resists changes in pH

Provides energy for a cell

Amplifies changes in pH

Resists changes in pH

What kinds of buffers are the respiratory and urinary system?

Multiple choice question.

Strong buffers

Physiological buffers

Chemical buffers

Physiological buffers

Any substance that binds H+ and removes it from solution as its concentration begins to rise, or releases H+ into solution as its concentration falls is classified as a Blank______ buffer. Examples include proteins, bicarbonate, and phosphate.

Multiple choice question.

body

physiological

chemical

chemical

A mechanism that resists pH changes is called a(n)

buffer

The addition of CO2 to the body fluids raises H+ concentration and lowers pH, while the removal of CO2 has the opposite effect. This is the basis for the strong buffering capacity of which system?

Multiple choice question.

Endocrine

Respiratory

Digestive

Urinary

Respiratory

Which type of buffer is defined as a substance that binds H+ and removes it from solution as its concentration begins to rise, or releases H+ into solution as its concentration falls?

Multiple choice question.

Physiological

Chemical

Volatile

Organic

Which physiological buffer system exerts an effect within a few minutes but cannot alter the pH as much as the urinary system?

Multiple choice question.

Reproductive system

Muscular system

Integumentary system

Respiratory system

Respiratory system

How can the respiratory system compensate for a drop in blood H+ concentrations?

Multiple choice question.

Reduced pulmonary ventilation eliminates more CO2 from the body, lowering the pH back to normal.

Reduced pulmonary ventilation allows CO2 to accumulate, lowering the pH back to normal.

Increased pulmonary ventilation allows CO2 to accumulate, raising the pH back to normal.

Increased pulmonary ventilation eliminates more CO2 from the body, lowering the pH back to normal.

Reduced pulmonary ventilation allows CO2 to accumulate, lowering the pH back to normal.

What kinds of buffers are the respiratory and urinary system?

Multiple choice question.

Physiological buffers

Strong buffers

Chemical buffers

Physiological buffers

The type of buffer that binds hydrogen ions and removes it from solution as its concentration goes up is a ___ buffer.

chemical

Of the two major physiological buffer systems, the respiratory system can restore the pH quickly, whereas the ____ system can take several hours to days to restore the pH.

urinary,

A drop in blood hydrogen ion concentrations triggers what?

Multiple choice question.

Reduction of pulmonary ventilation

An increase in pulmonary ventilation

Reduction of pulmonary ventilation

Which term refers to a tissue fluid pH above 7.45?

Multiple choice question.

Alkalosis

Hyponatremia

Hypernatremia

Acidosis

Alkalosis

Respiratory compensation involves correcting a pH imbalance by which of the following mechanisms?

Multiple choice question.

Changing in the rate of urine production

Changing the rate of H+ secretion in the renal tubules

Changing water and sodium excretion

Changing pulmonary ventilation rate

Changing pulmonary ventilation rate

Any substance that binds H+ and removes it from solution as its concentration begins to rise, or releases H+ into solution as its concentration falls is classified as a ______ buffer. Examples include proteins, bicarbonate, and phosphate.

Multiple choice question.

body

chemical

physiological

chemical

Choose all that may be caused by acidosis.

Multiple select question.

Hyperkalemia

Hypocalcemia

Hypercalcemia

Hypochloremia

Hypokalemia

Hyperchloremia

Hyperkalemia

Hypocalcemia

Hypochloremia

Describe respiratory compensation in response to hypercapnia.

Multiple choice question.

Pulmonary ventilation rate increases.

The renal tubules increase the rate of H+ secretion.

The renal tubules decrease the rate of H+ secretion.

Pulmonary ventilation rate decreases.

Pulmonary ventilation rate increases.

Hypokalemia

H+ diffuses from ICF to ECF. More K+ remains in the ICF to compensate for the H+ loss, causing a drop in ECF K+ concentration.

Hyperchloremia

More Cl- is reabsorbed from the renal tubules, so ingested Cl- accumulates in the ECF rather than being excreted.

Hypercalcemia

Alkalosis causes more Ca2+ to dissociate from plasma protein and citrate ions, raising the concentration of free Ca2+.

A pH below 7.35 in blood is considered a state of ___

acidosis

Choose all that are true regarding respiratory compensation.

Multiple select question.

It is effective in correcting for PCO2 imbalances.

It is slower than renal compensation, but better at restoring a fully normal pH.

It corrects the pH of body fluids by expelling or retaining CO2.

It is equally effective in correcting all causes of acidosis and alkalosis.

It is effective in correcting for PCO2 imbalances.

It corrects the pH of body fluids by expelling or retaining CO2.

Hyperkalemia

H+ diffuses into cells and displaces K+ (As K+ leaves the ICF, K+ concentration in the ECF rises).

Hypochloremia

More Cl- is excreted as NH4Cl to buffer the excess acid in the renal tubules, leaving less Cl- in the ECF.

Hypocalcemia

Acidosis causes more Ca2+ to bind to plasma protein and citrate ions, lowering the concentration of free, ionized Ca2+.

Describe respiratory compensation in response to hypocapnia.

Multiple choice question.

The renal tubules increase the rate of H+ secretion.

The renal tubules decrease the rate of H+ secretion.

Pulmonary ventilation rate increases.

Pulmonary ventilation rate decreases.

Pulmonary ventilation rate decreases.

Respiratory compensation involves correcting a pH imbalance by which of the following mechanisms?

Multiple choice question.

Changing water and sodium excretion

Changing in the rate of urine production

Changing pulmonary ventilation rate

Changing the rate of H+ secretion in the renal tubules

Changing pulmonary ventilation rate