Mastering A&P 2 CH 26 HW
Most fluid in the body is in the extracellular fluid (ECF) compartment. True False
False
Most of the hydrogen ions in the body come from acidic substances in the foods we ingest. -True -False
False
Parathyroid hormone (PTH) increases Ca2+ deposition in the bones. -True -False
False
The most abundant cation in the extracellular fluid is potassium. -True -False
False
Estrogens are chemically similar to __________ and are therefore associated with water retention. ADH aldosterone ANP rennin
aldosterone
If the osmotic pressure of the blood were increased above normal levels, which of the following volumes would also increase? blood volume total body water intracellular fluid volume interstitial fluid volume
blood volume Correct The higher osmotic pressure in the blood would draw water from the interstitial fluid, resulting in a higher blood volume and increased blood hydrostatic pressure.
Which of the following would NOT be expected to lead to edema? incompetent venous valves hyponatremia inflammation hypoproteinemia
hyponatremia Correct Hyponatremia is low levels of sodium in the blood. This can lead to dehydration, not edema.
Which condition would cause a drop in pH? hypokalemia hyperventilation hypoventilation hypernatremia
hypoventilation right answer feedback:Hypoventilation causes a drop in pH. Breathing slowly increases PCO2.
The only organ(s) of the body that can remove excess nonvolatile fixed acids is/are the __________. sweat glands spleen kidney lungs liver
kidney right answer feedback:The only organ of the body that can remove excess nonvolatile fixed acids is the kidney. Fixed acids are also called metabolic acids.
Most water is excreted via the ______________. -kidneys -intestines -skin -lungs
kidneys
Which organs are most important for the long-term regulation of acid-base homeostasis? -kidneys -lungs -gastrointestinal tract organs -cardiovascular organs
kidneys Correct The kidneys regulate pH over long-term time periods.
The largest percentage of body water is located in what compartment? intracellular fluid extracellular fluid interstitial fluid blood plasma
intracellular fluid
Pica, the desire to consume substances that are not normally considered food, such as chalk or clay, may be triggered by a deficiency of __________. calcium sodium water iron
iron
Antidiuretic hormone (ADH) acts on the _________ to __________ water excretion. -kidneys; decrease -intestines; decrease -kidneys; increase -intestines; increase
kidneys; decrease
Diuresis peaks __________ after drinking water. ten minutes half an hour one hour three hours
one hour
Electrolyte balance in the body usually refers to the balance of __________. salts proteins carbohydrates lipids
salts
Which of the following is not a hormone involved in water or electrolyte balance? thyroxine aldosterone antidiuretic hormone atrial natriuretic peptide
thyroxine Correct Thyroxine is a thyroid hormone that regulates metabolic activities and is not involved in water and electrolyte balance.
Which of the following would likely be increased by the release of atrial natriuretic peptide (ANP)? -blood pressure -aldosterone production -water excretion by the kidneys -antidiuretic hormone (ADH) production
water excretion by the kidneys ANP inhibits reabsorption in the kidney tubules, which then results in an increase in water excretion. ANP also directly inhibits the release of ADH, renin, and aldosterone.
Any arterial pH between __________ is considered physiological acidosis. 6.5 and 7.0 6.5 and 7.35 7.0 and 7.35 7.35 and 7.45
7.0 and 7.35
What type of intravenous infusion would you give to a runner who has collapsed after drinking too much water during the course of her marathon and why? A hypertonic saline solution to pull water out of her cells A hypertonic saline solution to cause more water to enter her cells An isotonic saline solution to pull water out of her cells A hypotonic saline solution to pull water out of her cells
A hypertonic saline solution to pull water out of her cells
What is, overall, the LEAST abundant ion, including all three compartments? K+ Na+ Cl− Ca2+
Ca 2+ Correct Ca2+ is the least abundant ion when summing all three compartments. It is particularly scarce in the intracellular compartment, although some cells, such as muscle, do sequester la
How does carbonic acid alone directly affect the pH of blood? Carbonic acid does not significantly affect blood pH. Carbonic acid acts as a buffer by binding to a strong acid, producing a weak acid and salt, thus lowering blood pH. Carbonic acid is a strong acid that, if added to blood, causes the pH to rise. Carbonic acid is a strong acid that dramatically lowers blood pH unless immediately neutralized by a buffer.
Carbonic acid does not significantly affect blood pH Correct The difference between strong acids and weak ones is their ability to dissociate in water. Weak acids such as carbonic acid do not completely dissociate, which limits their effect on pH, whereas strong acids such as HClHCl completely dissociate.
How do physiological buffer systems differ from chemical buffer systems? -Physiological buffer systems operate faster than chemical buffers, but they are less powerful. -Chemical buffer systems convert strong acids or bases into weak acids or bases, while physiological buffer systems remove acids and bases from the body. -Physiological buffer systems use different compounds than those used by chemical buffer systems. -Physiological buffer systems regulate the pH within specific organs, while chemical buffer systems regulate body fluid pH.
Chemical buffer systems convert strong acids or bases into weak acids or bases, while physiological buffer systems remove acids and bases from the body. Correct Physiological buffer systems work by regulating the quantity of acids and bases in the body by excreting compounds such as carbon dioxide or hydrogen ions.
What negatively charged ion is reabsorbed by the renal tubules when the blood pH is drawing near its alkaline limit? -PO4 -3 -Cl- -HCO3 - -NO2 -
Cl-
Which of these combinations of values would help you determine if your patient was suffering from metabolic acidosis? -Increased blood HCO3- levels and decreased pH -Increased PC02 levels in the blood and decreased pH -Decreased blood HCO3- levels and decreased pH -Decreased PC02 levels in the blood and increased pH levels
Decreased blood HCO3- levels and decreased pH Correct If the problem is not respiratory, then often carbon dioxide levels are normal. If the kidneys are excreting too much HCO3-, then your pH will decrease.
Which of the following statements about fluid movement is NOT correct? -Exchange between the plasma and the intracellular fluid occurs across the cell membrane. -Under normal circumstances, lymph vessels help maintain fluid balance, especially between the plasma and the interstitial fluid. -Exchange between interstitial fluid and intracellular fluid occurs across the plasma membrane. -Exchanges between plasma and interstitial fluid happen between capillary walls.
Exchange between the plasma and the intracellular fluid occurs across the cell membrane Correct Exchange between the plasma and the intracellular fluid would have to involve exchange through the interstitial fluid.
What is the most abundant intracellular cation? Cl- K+ HPO4 2- Na+
K+ Correct K+ is the most abundant cation in the intracellular fluid.
What is the most common cation found in the interstitial fluid? Na+ HPO4 2- K+ cl-
Na+
The only cation exerting significant osmotic pressure in the ECF is __________. K+ Ca2+ Fe2+ Na+ Mg2+
Na+ right answer feedback:Na+ is the only cation exerting significant osmotic pressure in the ECF.
Renal acid-base control mechanisms are coupled to __________. water intake plasma protein levels Na+ transport ADH secretion
Na+ transport
Which of the following is true of a patient with arterial blood pH of 7.6? The patient has alkalosis but is in the normal homeostatic range. The patient has alkalosis and is out of the normal homeostatic range. The patient has acidosis and is outside of the normal homeostatic range. The patient has acidosis but is in the normal range.
The patient has alkalosis and is out of the normal homeostatic range Correct The normal pH range of arterial blood is 7.4 to 7.45. A higher pH is a sign of alkalosis
Which statement about acids is true? When high in the body, they cause alkalosis. Weak acids only dissociate partially in solution. They have little physiological effect on chemical reactions in cells. Most acid is a result of ingestion with food. Our bodies have few ways to deal with excess amounts of acids.
Weak acids only dissociate partially in solution right answer feedback:Strong acids dissociate fully, and weak acids dissociate incompletely.
If a person exercises for a long time, lactic acid will start to build up in his or her muscles. Which of the following would you expect to happen as the lactic acid first starts to be formed? -Weak acids in the muscles will act as buffers and resist or minimize any pH change. -More water will move to the muscles to buffer the acid. -More water will move to the muscles to move out the acid. -Weak bases in the muscles will act as buffers and resist or minimize any pH change.
Weak bases in the muscles will act as buffers and resist or minimize any pH change. Excellent! Bases buffer acids, and acids buffer bases.
An increase in blood CO2 levels leads to __________. a decrease in carbonic acid an increase in blood pH a drop in blood pH a decreased respiratory rate
a drop in blood pH Correct An increase in CO2 results in the formation of more carbonic acid, which leads to an increase in acidity, or a drop in pH.
Which of the following is most likely to trigger the release of renin? -an increase in aldosterone production -a drop in blood pressure -an increase in water reabsorption -an increase in blood pressure
a drop in blood pressure When baroreceptors in the heart and blood vessels sense a drop in blood pressure, they trigger juxtaglomerular cells of the kidney to release renin.
A major stimulus for the release of antidiuretic hormone is __________. -an increase in potassium levels in the ICF -stimulation of the baroreceptors -a rise in plasma osmolality -an increase in ECF water concentration -inhibition of the osmoreceptors
a rise in plasma osmolality right answer feedback:A major stimulus for the release of antidiuretic hormone is a rise in plasma osmolality. ADH results in increased water reabsorption.
Which of the following tissues is the least hydrated? adipose tissue bone muscle tissue nervous tissue
adipose tissue
When the concentration of Na+ in the ECF decreases, __________. aldosterone levels increase a person experiences increased thirst more ADH is released osmoreceptors are stimulated ANP levels increase
aldosterone levels increase right answer feedback:When the concentration of Na+ in the ECF decreases, there is an increase in the level of aldosterone, which causes facultative Na+ reabsorption.
Which of the following individuals would have the most body water? a healthy young male an older obese person a healthy young female an infant
an infant
The most important buffer system of extracellular fluid, such as plasma, is the __________ buffer system. bicarbonate protein hemoglobin phosphate
bicarbonate
The pH of the ECF is maintained in homeostatic balance by which chemical buffer system? bicarbonate phosphate lipid protein
bicarbonate
When atrial natriuretic peptide is released by the heart because of increased blood pressure, it causes __________. increased renin secretion vasoconstriction decreased sodium and water reabsorption increased antidiuretic-hormone secretion
decreased sodium and water reabsorption right answer feedback:ANP reduces blood pressure and blood volume by inhibiting nearly all events that promote vasoconstriction, sodium retention, and water retention.
Which of the following would NOT be expected to occur as a result of dehydration? -edema -reduced urine flow -hypovolemic shock -shrinkage of body cells
edema Correct Edema is tissue swelling that results from an atypical accumulation of fluid in the interstitial space. During dehydration, this fluid would be reduced.
Parathyroid hormone __________. results in a lower blood calcium level activates osteoblasts enhances release of calcium from bone is released when aldosterone levels climb targets the thyroid gland
enhances release of calcium from bone right answer feedback:PTH activates osteoclasts, which break down the bone matrix, releasing calcium.
One way the kidneys maintain HCO3 - balance by __________. -reabsorbing H+ -reabsorbing CO2 -generating Na+ ions -generating new HCO3-
generating new HCO3-
Which of the following is NOT an electrolyte? -potassium -glucose -chloride -sodium
glucose
Acidosis results in increasing levels of what ion? hydrogen calcium phosphorus sodium chloride
hydrogen right answer feedback:Acidosis refers to high H+ concentration.
The condition in which sodium levels are too low is referred to as __________. Cushing's syndrome hyponatremia hypokalemia hypernatremia aldosteronism
hyponatremia
All of the following factors would stimulate the hypothalamic thirst center EXCEPT __________. increased angiotensin II secretion decreased saliva production hypotonic extracellular fluid a decline in blood volume right answer feedback:
hypotonic extracellular fluid
Which of the following is associated with a swelling of cells? -edema -hypoproteinemia -hypotonic hydration -dehydration
hypotonic hydration
What type of water imbalance increases the amount of fluid in both cells and tissue? -hypotonic hydration -inflammation -edema -dehydration
hypotonic hydration Correct Hypotonic hydration occurs when extracellular fluid becomes so hypotonic (dilute) that water is pulled into the cells. Excess water is present in cells and extracellular compartments.
What is a likely result of rapidly consuming excessive quantities of electrolyte? -decreased sensation of thirst -increased aldosterone production -decreased blood pressure -increased blood pressure
increased blood pressure Correct Increased electrolyte levels increase ECF osmolality, which then triggers an increase in blood volume via osmosis and, therefore, an increase in blood pressure.
What might be a sign that the renin-angiotensin-aldosterone mechanism is NOT producing enough aldosterone? increased blood volume increased excretion of water and NaClNaCl in urine increased blood pressure increased antidiuretic hormone (ADH) production Submit
increased excretion of water and NaCl in urine Correct Aldosterone is primarily responsible for triggering reabsorption of water and NaClNaCl.
Which of the following does NOT serve as a source of acids in the body? aerobic breakdown of glucose CO2 in the blood fat metabolism ingesting of bicarbonate
ingesting of bicarbonate
Water lost through expired air is referred to as __________. metabolic water water of oxidation insensible water loss water intake
insensible water loss
Edema is the accumulation of fluid in the __________. plasma organelles interstitial space intracellular space
interstitial space
Angiotensinogen is constantly produced by the __________. -adrenal cortex -liver -kidney -atrial cells of the heart
liver The liver continuously secretes angiotensinogen.
The most important renal mechanism for regulating acid-base balance of the blood involves __________. maintaining phosphate balance maintaining CO2 balance maintaining HCO3 - balance maintaining water balance
maintaining HCO3 - balance Correct Excretion of bicarbonate is a long-term mechanism that the kidneys contribute to acid-base regulation.
A patient is admitted to the hospital with the following plasma values: pH = 7.2, pCO2 = 25 mmHg, and HCO3 −− = 18 mEq/L. What is the acid base imbalance? -respiratory acidosis with metabolic compensation -metabolic acidosis with no compensation -metabolic alkalosis with respiratory compensation -metabolic acidosis with respiratory compensation
metabolic acidosis with respiratory compensation Correct Yes, the low bicarbonate indicates this is a metabolic acidosis. Since CO2 is below the normal range, this indicates there is a respiratory compensation.
Starvation would cause which of the following acid-base conditions? Also, determine what type of compensation (metabolic or respiratory) there would be. -metabolic alkalosis with respiratory compensation -respiratory alkalosis with metabolic compensation -metabolic acidosis with respiratory compensation -respiratory acidosis with metabolic compensation Submit
metabolic acidosis with respiratory compensation Correct Yes, this is known as a ketosis (due to the breakdown of fat for metabolism), and the respiratory system would increase respiration to compensate for the excess hydrogen ions.
Diarrhea can lead to which acid/base disturbance? Assuming compensation, would it be a metabolic or respiratory compensation? -metabolic acidosis with respiratory compensation -respiratory alkalosis with metabolic compensation -metabolic alkalosis with respiratory compensation -metabolic alkalosis with respiratory compensation
metabolic acidosis with respiratory compensation Correct Yes, with the loss of bicarbonate ions, this is a metabolic acidosis. If compensated, it would be a respiratory compensation.
A patient is admitted to the hospital with the following plasma values: pH = 7.5, pCO2 = 45 mmHg, and HCO3 −− = 30 mEq/L. What is the acid-base imbalance? -respiratory alkalosis with metabolic compensation -respiratory acidosis with metabolic compensation -metabolic alkalosis with no compensation -metabolic alkalosis with respiratory compensation
metabolic alkalosis with no compensation Correct Yes, since HCO3¯ is 30 (above the normal range of 22 to 26 mEq/L), this is definitely a metabolic alkalosis. There is no respiratory compensation since CO2 is within the normal range.
A friend has acid indigestion after eating a big meal. Which of the following would act as a buffer and help ease his pain? -milk of magnesia, with a pH of 10 -black coffee, with a pH of 5 -cola, with a pH of 3 -pure water, with a pH of 7
milk of magnesia, with a pH of 10 Correct Excellent! Excess acid can be buffered by the addition of an alkaline or base.
What is the most abundant cation in intracellular fluid? magnesium sodium bicarbonate calcium potassium
potassium right answer feedback:Potassium is the most abundant cation in the intracellular fluid and is required for essential metabolic activities, influencing the resting membrane potential and normal neuromuscular functioning.
All of the following would occur if there were an increase in plasma osmolality EXCEPT __________. concentrated urine production of large amounts of urine release of ADH thirst
production of large amounts of urine right answer feedback:If the plasma osmolality were to increase, the body would conserve water and scant amounts of concentrated urine would be formed.
Which of the following would increase sodium excretion? -glucocorticoids -aldosterone -progesterone -estrogens
progesterone
The most important buffer system in the intracellular fluid compartment (ICF) is the __________ buffer system. bicarbonate sulfate phosphate chloride protein
protein right answer feedback:Most of the buffering power of body fluids resides in cells, and most of this reflects the buffering activity of intracellular proteins.
What is the most significant direct effect of aldosterone release? -activation of angiotensinogen into angiotensin I -rapid drop in blood pressure -stimulate renin production via juxtaglomerular cells of the kidneys -reabsorption of sodium in kidney tubules
reabsorption of sodium in kidney tubules Correct Aldosterone causes the reabsorption of sodium, and because water follows salt, water is also reabsorbed, increasing blood pressure and volume.
ECF osmolarity is primarily dependent on ___________. -water content of the body only -blood pressure -relative quantities of sodium and water -sodium content of the body only
relative quantities of sodium and water Correct ECF osmolality is primarily a measure of the concentration of sodium per kilogram of water. This concentration depends on both water and sodium levels, and a disruption of either affects osmolality.
Someone who is suffocating would develop _________________. -respiratory alkalosis respiratory acidosis -metabolic acidosis -metabolic alkalosis
respiratory acidosis
A patient is admitted to the hospital with the following plasma values: pH = 7.2, pCO2 = 55 mmHg, and HCO3 −− = 30 mEq/L. What is the acid base imbalance? -metabolic alkalosis with respiratory compensation -metabolic acidosis with respiratory compensation -respiratory alkalosis with metabolic compensation -respiratory acidosis with metabolic compensation
respiratory acidosis with metabolic compensation Correct Yes, this is a respiratory acidosis with metabolic compensation. Since pCO2 is above the normal range, it is the cause of the acidosis. HCO3 −− is increased to compensate, which is a metabolic compensation.
Emphysema can lead to which acid/base disturbance? What would be the compensation? -respiratory alkalosis; kidneys will retain more H+ and excrete HCO3 -respiratory acidosis; hyperventilation -respiratory acidosis; kidneys will retain more HCO3 -metabolic acidosis; hypoventilation by the lungs Submit
respiratory acidosis; kidneys will retain more HCO3 Correct Yes, a patient with emphysema would retain CO2, leading to a respiratory acidosis. The kidneys would compensate by retaining HCO3 −− and excreting H+.
Hyperventilation can lead to __________. -metabolic alkalosis -respiratory acidosis -respiratory alkalosis -metabolic acidosis
respiratory alkalosis
Normal arterial blood pH is __________. slightly alkaline slightly acidic strongly alkaline neutral highly acidic
slightly alkaline right answer feedback:Normal arterial blood pH is 7.4, which is slightly alkaline.
The most prevalent electrolyte in the extracellular fluid is __________. potassium magnesium sodium calcium chloride phosphate
sodium
What component in body fluids adds to the fluids' electrical conductivity? -lipids -glucose -urea -sodium
sodium Correct Electrolytes such as sodium are so named because they dissociate into ions in water and can create electrical currents in the body fluids.
Which of the electrolyte solutes is most responsible for osmotic pressure in body fluids and cells? -sodium -phosphate -potassium -calcium
sodium Correct Sodium is the most abundant cation in ECF, and the amount of sodium present significantly affects ECF volume and water distribution throughout the body.
The most important factor that influences K+ secretion is _________. -the concentration of K+ in the ECF -the concentration of Na+ in blood plasma -water balance in the body -the level of aldosterone in the plasma
the concentration of K+ in the ECF
Infants are more likely to experience problems regulating acid-base balance because of several factors, including __________. lower amount of fluid intake and output in infants high residual volume of infant lungs the inefficiency of infant kidneys decreased surface area relative to body volume low rate of insensible water loss from skin
the inefficiency of infant kidneys right answer feedback:The kidneys are immature at birth; they are approximately half as proficient at concentrating urine as mature kidneys. Infant kidneys are also inefficient in ridding the body of acids.
Hypersecretion of aldosterone results in hypokalemia, which causes hyperpolarization of neurons; this in turn results in ______. -increased speed of sodium-potassium pump activity in order to compensate for the reduced concentration of potassium ions -decreased plasma membrane permeability to potassium ions -the need for a stronger than normal stimulus in order to trigger an action potential -a craving for more salt in the diet Submit
the need for a stronger than normal stimulus in order to trigger an action potential Correct 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, more cations must enter the cytoplasm for the cell to reach threshold.
Which of the following has the LEAST influence over the pH of blood plasma? -the phosphate buffer system -respiratory rate -the protein buffer system -the bicarbonate buffer system
the phosphate buffer system
Which of the following puts infants at increased risk for dehydration? -their low surface area to volume ratio -their inefficient kidneys -their high residual lung volume -their low metabolic rate
their inefficient kidneys
The major source of water loss from the body is __________. sweat urine insensible skin loss insensible respiratory loss feces
urine Urine accounts for roughly 60% of the body's water loss.
