Human Physio Ch. 20 Fluid and Electrolyte
Compare and contrast the terms in each set: (a) principal cells and intercalated cells (b) renin, ANG II, aldosterone, ACE (c) respiratory acidosis and metabolic acidosis, including causes and compensations (d) water reabsorption in proximal tubule, distal tubule, and ascending limb of the loop of Henle (e) respiratory alkalosis and metabolic alkalosis, including causes and compensations
(a) Both are in the distal nephron. P cells are associated with aldosteronemediated Na+ reabsorption; I cells are involved with acid-base regulation. (b) All are parts of the RAS system. Renin and ACE—enzymes; ANG II and aldosterone—hormones. See Figure 20.10. (c) In both, body pH falls below 7.38. Respiratory—results from CO2 retention (from any number of causes); metabolic—results from excessive production of metabolic acids. Respiratory compensation—renal H+ excretion and HCO3- retention. Metabolic compensation—increased ventilation, renal H+ excretion, and HCO3- retention. Respiratory—arterial PCO2 is elevated; metabolic—PCO2 usually decreased. (d) Proximal tubule—not regulated; distal nephron—regulated by vasopressin. Ascending limb—impermeable to water. (e) Both—pH goes above 7.42. Metabolic—may be caused by excessive ingestion of bicarbonate-containing antacids or vomiting; respiratory—hyperventilation. Metabolic compensation—decrease ventilation, decreased renal H+ excretion, increased HCO3- excretion. Respiratory compensation—decreased renal H+ excretion, increased HCO3- excretion.
Vasopressin
(antidiuretic hormone - ADH) water retention made in pituitary glands, target is nephrons of the kidneys, helps control the balance of water in the body by causing the kidneys to reabsorb water. Mechanism by regulation of water pores = aquaporin
The osmolarity in the deepest part of the loop of Henle is ________ mOsM. ANSWER: 900 1200 300 100 None of these answers are correct.
1200
April thinks she has an abscessed tooth (a bacterial infection). If she does, what type of white blood cell would you expect to see in elevated numbers in a differential count? A. neutrophils B. eosinophils C. monocytes D. basophils E. lymphocytes
A
During severe dehydration which of the following does NOT occur? A. Aldosterone levels increase to help retain sodium ions. B. Vasopressin levels increase. C. Cardiac output increases. D. Blood volume and pressure both decrease. E. There will be an increase in thirst
A
If sodium increases in the ECF, water will move from [A. cells to the ECF/B. the ECF to cells].
A
The Na+-K+-ATPase is usually located on the [A. basolateral/B. apical] membrane(s) of epithelial cells lining the digestive tract.
A
The [A. partial pressure/B. concentration] gradient is the more important parameter governing movement of carbon dioxide from the blood into the alveoli.
A
Severe Dehydration
A. Vasopressin levels increase. B. Cardiac output increases. C. Blood volume and pressure both decrease. D. There will be an increase in thirst.
Drugs that treat hypertension by preventing Angiotensin I from becoming Angiotensin II are called ANSWER: beta blockers. ACE inhibitors. diuretics. calcium channel blockers.
ACE inhibitors.
The hormone that directly controls water excretion by the kidneys is ANSWER: aldosterone. ADH. angiotensin. epinephrine. ANP.
ADH
When ventilation increases, what happens to arterial PCO2? To plasma pH? To plasma H+ concentration?
Arterial PCO2 decreases, pH increases, and plasma H+ concentration decreases.
Which of the following statements concerning the hormone atrial natriuretic peptide is FALSE? ANSWER: -Atrial natriuretic peptide reduces the sensation of thirst. -Atrial natriuretic peptide is produced by cells in the heart. -Atrial natriuretic peptide increases aldosterone secretion. -Atrial natriuretic peptide suppresses ADH secretion. -Atrial natriuretic peptide promotes sodium loss at the kidneys.
Atrial natriuretic peptide increases aldosterone secretion.
Movement from the glomerular capillary to the Bowman's capsule is called [ A. excretion/B. filtration].
B
Reactive hyperemia is A. increased blood pressure after stress. B. increased blood flow following a period of reduced blood flow. C. lack of blood flow due to an allergic reaction. D. reflex contraction of smooth muscle in response to stress. E. none of the above
B
The forces that are important for glomerular filtration include all of the following EXCEPT: A. fluid hydrostatic pressure in the Bowman's space. B. oncotic pressure in the Bowman's space. C. oncotic pressure in the glomerular capillaries. D. fluid hydrostatic pressure in the glomerular capillaries. E. none, they are all correct.
B
Under steady-state conditions, the rate at which oxygen enters pulmonary capillaries from alveolar air is equal to the rate at which A. carbon dioxide is produced in respiring tissue B. oxygen is consumed in respiring tissue C. carbon dioxide leaves the pulmonary capillaries and enters alveolar air. D. oxygen is delivered to alveoli in inspired air E. oxygen is carried out of the alveoli in expired air
B
When the pH of the extracellular fluid decreases, the kidneys [A. reabsorb/ B. secrete] more H+ ions.
B
Which of the following statements concerning the hormone atrial natriuretic peptide is FALSE? A. Atrial natriuretic peptide is produced by cells in the heart. B. Atrial natriuretic peptide increases aldosterone secretion. C. Atrial natriuretic peptide reduces the sensation of thirst. D. Atrial natriuretic peptide promotes sodium loss at the kidneys. E. Atrial natriuretic peptide suppresses ADH secretion.
B
Functions of the kidneys include all of the following EXCEPT: A. regulation of blood osmolarity B. maintenance of ion balance in body fluids C. regulation of blood protein levels D. homeostatic regulation of blood pH E. regulation of extracellular fluid volume
C
In respiring tissues, a rise in blood PCO2 causes all of the following EXCEPT A. a rise in the concentration of carbaminohemoglobin B. a rise in bicarbonate concentration C. an increase in the affinity of hemoglobin for oxygen D. an increase in H+ ion concentration E. an increase in hemoglobin unloading of oxygen
C
In the lungs, for maximum efficiency in loading oxygen into RBCs it would be helpful if A. DPG levels in the red blood cells would be high. B. the pH would be slightly acidic. C. the temperature would be slightly lower than normal body temperature. D. the PO2 would be about 70 mm Hg. E. all of the above
C
When distinguishing between alveolar and intrapleural pressures, which of the following is INCORRECT? A. The alveloar pressure equilibrates with atmospheric pressure during the respiratory cycle. B. Intrapleural pressure is the pressure within the pleural sac. C. Changes in alveolar pressure drives the changes in intrapleural pressure. D. Intrapleural pressure is always lower than atmospheric pressure, E. Alveolar pressure is the pressure inside the alveoli.
C
Which of the following is NOT true about angiotensin II? A. is a potent vasoconstrictor B. increases cardiac output C. activates parasympathetic output D. stimulates thirst E. elevates blood pressure
C
Which of the following statements about the kidney is TRUE? A. Podocytes are specialized endothelial cells lining the peritubular cappilaries. B. Damage to the medulla region would disrupt the function of the glomerulus. C. Granular cells are specialized smooth muscle cells that secrete the enzyme Renin. D. Water leaves the ascending limb of the loop of Henle by osmosis. E. The vast majority of nutrients are reabsorbed in the collecting duct
C
Symptoms of low plasma pH may include ANSWER: numbness, tingling, or muscle twitches. CNS depression and confusion and disorientation. CNS depression; confusion and disorientation; and numbness, tingling, or muscle twitches. confusion and disorientation. CNS depression.
CNS depression and confusion and disorientation.
Which of the following statements about blood is FALSE? A. Plasma is mostly water. B. A normal adult hematocrit would be around 45%. C. When blood contacts injured tissue, clotting factors follow the extrinsic pathway. D. Fibrinogen is the insoluble product forming a clot. E. Calcium is an important co-factor used during coagulation.
D
How do the two limbs of the loop of Henle differ in their permeability to water? What makes this difference in permeability possible?
Descending limb: permeable to water but lacks transporters for salts. Ascending limb: impermeable to water but reabsorbs NaCl
Carbon dioxide is more soluble in water than oxygen. To get the same amount of oxygen to dissolve in plasma as carbon dioxide, you would have to A. increase the rate of plasma flow through the lungs B. decrease the temperature of the plasma. C. decrease the partial pressure of nitrogen. D. decrease the alveolar ventilation rate. E. increase the partial pressure of oxygen.
E
Which of the following would occur if the mean arterial pressure increased from 95 to 125 mm Hg? A. GFR would decrease because of an increase in Bowman's capsule hydrostatic pressure. B. GFR would not change due to activation of the parasympathetic nervous system. C. GFR would not change due to activation of the sympathetic nervous system. D. GFR would increase because of an increase in glomerular hydrostatic pressure. E. GFR would not change due to autoregulation
E
Which of the following would occur if the mean arterial pressure increased from 95 to 125 mm Hg?
GFR would not increase due to autoregulation
The primary osmoreceptors are located in the ANSWER: kidney. pons. hypothalamus. medulla. stomach.
HYPOTHALAMUS
Metabolic Alkalosis
Hyperventilation; low CO2 = low H+ and high HCO3- = high pH
SECRETES H+ and Reabsorbs HCO3- :
Proximal tube
Why do patients taking loop diuretics need to take supplemental potassium? ANSWER: -They cause active reabsorption of potassium in the distal convoluted tubule. -They inhibit intestinal absorption of potassium. -They inhibit the reabsorption of potassium as well as sodium in the loop of Henle. -They cause active secretion of potassium in the loop of Henle.
They inhibit the reabsorption of potassium as well as sodium in the loop of Henle.
Renal tubule cells in the kidney medulla are constantly exposed to high extracellular osmolarity. How do they maintain normal cell volume? ANSWER: -They add or remove aquaporins as needed. -They synthesize water molecules through increased metabolism to offset volume loss. -They maintain a water-impermeable membrane. -They synthesize organic solutes as needed to match the osmolarity.
They synthesize organic solutes as needed to match the osmolarity.
acidosis may be accompanied by hyperkalamenia
True
Cortical Collecting Duct: Intercalated cell control of acidosis:
Type A: controls acidosis; H+-K+- ATPase; H+ secreted out into lumen - two ways one in exchange for K+ one just pump H+; CA - converts high H+ to CO2; goes into cell reconverted to HCO3 and H+
Cortical Collecting Duct: Intercalated cell control of acidosis control of alkalosis
Type B: placement of the two pumps - now on basal side so that pump H+ into blood difference in placement of pumps dicates need for two cell types
Dehydration
a decrease in blood volume, therefore blood pressue but also an increase in osmolarity
Angiotensin II
a peptide hormone that causes vasoconstriction and a subsequent increase in blood pressure. It is part of the renin-angiotensin system, which is a major target for drugs that lower blood pressure.
Which of the following is NOT true about angiotensin II? ANSWER: activates parasympathetic output elevates blood pressure is a potent vasoconstrictor increases cardiac output stimulates thirst
activates parasympathetic output
A hormone that helps to regulate the sodium ion concentration of the blood is ANSWER: parathormone. somatotropin. thymosin. cortisol. aldosterone.
aldosterone.
A rise in angiotensin II levels would result in ANSWER: -increased retention of sodium ions at the kidney. -elevated blood pressure. -increased water retention. -increased blood volume. -all of these effects.
all of these effects.
Renal compensation for acidosis:
ammonia (NH3-) and phosphate (HPO4-)
Respiratory Acidosis
anaerobic metabolism = high H+; Normal/low CO2 leads to high H+ and low HCO3- = low pH
ACE converts ANSWER: renin to aldosterone. angiotensin I to angiotensin II. angiotensinogen to angiotensin I. renin to angiotensinogen. angiotensin II to aldosterone.
angiotensin I to angiotensin II.
enzyme renin is responsible for the activation of ANSWER: erythropoietin. angiotensin. cortisol. adrenaline. atrial natriuretic peptide.
angiotensin.
The _________ __________ is impermeable to water.
ascending limb
ANP
atrial natriuretic peptide; (includes brain natriuretic peptide); increase water/salt loss; Released from atria in response to increased volume May act as a "check" on RAAS: decreases renin (decrease BP) and increases GFR; antagonize the Reninangiotensin-aldosterone axis; increase strech of atrial cells releases ANP.
Most of the carbon dioxide in the blood is transported as
bicarbonate
Angiotensin I is converted to angiotensin II by enzymes primarily located in the ANSWER: lungs. blood vessels. kidneys. liver. heart.
blood vessels.
The most important factor affecting the pH of plasma is the concentration of ANSWER: ketone bodies. organic acids. carbon dioxide. lactic acid. hydrochloric acid.
carbon dioxide.
Thirst is ANSWER: -controlled by centers in the hypothalamus, triggered by increased osmolarity, and relieved only when plasma osmolarity is decreased. -controlled by centers in the hypothalamus. -controlled by centers in the hypothalamus and triggered by increased osmolarity. -triggered by increased osmolarity. -relieved only when plasma osmolarity is decreased.
controlled by centers in the hypothalamus.
The anatomical arrangement of the kidney that allows transfer of solutes from one blood vessel to another is called the ________ system. ANSWER: symbiotic countercurrent exchange transcytosis complimentary
countercurrent exchange
in loop , water movement is ____________ from ions
dissociated
Removal of excess water in urine is known as ANSWER: ketoacidosis. diuresis. filtration. diarrhea.
diuresis
if you add H+ ....
drive reaction to left some of HCO3 is used as buffer Increased CO2 - blow off in lung added H+ = metabolic acidosis)
During normal quiet breathing, when the inspiratory muscles relax, the rib cage returns to its original position as a result of
elastic recoil
Metabolic Acidosis
fail to blow off enough CO2; High CO2 causes high H+ and low HCO3 - = low pH
A hemoglobin molecule is composed of
four protein chains and four heme groups.
Shrinkage of hepatocytes in the liver causes them to cause which of the following? ANSWER: -glucogen production only -both glycogen production and protein synthesis -protein synthesis only -both glycogen breakdown and protein synthesis -glycogen breakdown only
glycogen breakdown only
What three things trigger vasopressin release?
high osmolarity (more than 280), low blood volume, low blood pressure
collecting duct - variable response to gradient to conserve or excrete water. Regulated by ______.
hormones
An increase in plasma potassium levels is properly called ANSWER: hyperkalemia. hypernatremia. hyperpotasseplasmia. hyperpotassemia. hypercalcemia.
hyperkalemia.
Atrial natriuretic peptide ANSWER: increases the GFR. increases the GFR and inhibits the release of renin. stimulates the release of renin. increases the GFR and stimulates the release of renin. inhibits the release of renin.
increases the GFR and inhibits the release of renin.
in DCT (distal tubule), water movement and Na+ and K+ ion movement are
independently regulated
When baroreceptors in the carotid and aortic bodies register increased blood pressure, this results in ANSWER: inhibition of ADH secretion. secretion of ADH. increased glomerular filtration. increased thirst. decreased urine production.
inhibition of ADH secretion.
When venous return is increased, stretch receptors in the atria of the heart are activated. This results in ANSWER: decreased urine production. increased thirst. secretion of ADH. inhibition of ADH secretion.
inhibition of ADH secretion.
Most body water is located ANSWER: in lumens of organs open to the outside. in plasma. inside cells. in interstitial fluid.
inside cells
The PCT (proximal tubule) always stays
iso-osmotic (300 osm)
Excess potassium ions are eliminated from the body by the ANSWER: spleen. sweat glands. kidneys. digestive system. liver.
kidneys.
Stimuli for the activation of the RAAS pathway include ANSWER: -low blood pressure in arterioles in the nephron, a decrease in fluid flow through the distal tubule, and high blood pressure in the renal artery. -low blood pressure in arterioles in the nephron and a decrease in fluid flow through the distal tubule. -a decrease in fluid flow through the distal tubule only. -high blood pressure in the renal artery only. -low blood pressure in arterioles in the nephron only.
low blood pressure in arterioles in the nephron and a decrease in fluid flow through the distal tubule.
Paracrine feedback from the ________ in the distal tubule to the granular cells stimulates release of ________. ANSWER: aquaporings, vasopressin glomerulus, aldosterone macula densa, angiotensin converting enzyme macula densa, renin
macula densa, renin
The high ________ osmolarity allows urine to be concentrated. ANSWER: medullary interstitial plasma filtrate cortical interstitial
medullary interstitial
AQP2 water pores are added to the cell membrane by exocytosis and withdrawn by endocytosis in a process known as ANSWER: transcytosis. secretion. countercurrent exchange. membrane recycling.
membrane recycling.
Prolonged vomiting of the stomach's contents can result in ANSWER: respiratory acidosis. metabolic acidosis. respiratory alkalosis. metabolic alkalosis. None of the answers are correct.
metabolic alkalosis.
The hormone that regulates water excretion by the kidneys ANSWER: -increases water permeability throughout the kidney tubules. -decreases water permeability throughout the kidney tubules. -only decreases water permeability in certain portions of the kidney tubules. -only increases water permeability in certain portions of the kidney tubules.
only increases water permeability in certain portions of the kidney tubules.
Cell volume (and therefore cell function) in most cells is dependent upon careful regulation of ANSWER: resting membrane potential. permeability of cell membranes. osmolarity of extracellular fluid. blood pressure. volume of extracellular fluid.
osmolarity of extracellular fluid.
Water reabsorption by the kidneys is a result of ANSWER: both passive and active transport processes. cotransport with ions. exchange with ions. osmosis.
osmosis
Aldosterone
principle cells (P); salt balance "salt-retaining hormone" which promotes the retention of Na+ by the kidneys. na+ retention promotes water retention, which promotes a higher blood volume and pressure. steroid; regulates trxn of ion transporters & Na/K ATPase; increases Na+ resorption & K+ excretion; in DCT and cortical collecting ducts
Aldosterone ANSWER: a promotes sodium retention in the kidneys. b helps decrease blood volume. c increases the concentration of sodium in urine. d functions in pH regulation. e is secreted in response to elevated levels of sodium in the blood.
promotes sodium retention in the kidneys.
Juxtaglomerular cells in the nephron secrete ANSWER: angiotensin converting enzyme. angiotensin I. angiotensinogen. aldosterone. renin.
renin.
The RAAS pathway begins with ANSWER: secretion of angiotensinogen. secretion of aldosterone. secretion of antidiuretic hormone. secretion of the enzyme renin. secretion of angiotensin converting enzyme.
secretion of the enzyme renin.
Osmoreceptors depolarize after they ________ in response to ________ plasma osmolarity. ANSWER: shrink, increased swell, decreased shrink, decreased swell, increased
shrink, increased
Kidneys respond relatively ________ to changes in blood volume. ANSWER: quickly slowly
slowly
The principal ions in the ECF are ANSWER: sodium, chloride, and bicarbonate. sodium and chloride sodium, potassium, and hydrogen. sodium, potassium, and calcium.
sodium, chloride, and bicarbonate.
Angiotensin II ANSWER: -causes widespread vasoconstriction throughout the body only. -stimulates thirst only. -stimulates thirst, causes widespread vasoconstriction throughout the body, and causes the synthesis and release of aldosterone from the adrenal cortex. -stimulates thirst and causes widespread vasoconstriction throughout the body. -causes the synthesis and release of aldosterone from the adrenal cortex.
stimulates thirst, causes widespread vasoconstriction throughout the body, and causes the synthesis and release of aldosterone from the adrenal cortex.
The hormone ADH ANSWER: -causes the kidneys to produce a large volume of urine. -stimulates the kidneys to retain sodium ion. -is secreted by the anterior pituitary gland in -response to changes in blood osmolarity. -stimulates water conservation at the kidneys. -All of the answers are correct.
stimulates water conservation at the kidneys.
Decreased ECF volume causes ANSWER: -parasympathetic output from the cardiovascular control center to increase. -arteriolar vasodilation. -the force of ventricular contraction to decrease. -sympathetic output from the cardiovascular control center to increase. -sympathetic output from the cardiovascular control center to increase and arteriolar vasodilation.
sympathetic output from the cardiovascular control center to increase.
As a result of respiratory alkalosis, ANSWER: the body retains less carbon dioxide. the respiratory rate increases. the kidneys secrete fewer hydrogen ions. the tidal volume increases. the kidneys conserve bicarbonate.
the body retains less carbon dioxide.
The primary role of the carbonic acid-bicarbonate buffer system is ANSWER: -the prevention of pH changes caused by organic and fixed acids. -to buffer the urine. -to buffer carbonic acid formed by carbon dioxide. -to buffer stomach acid. -to increase the amount of carbonic acid during ventilation.
the prevention of pH changes caused by organic and fixed acids.
Why is sodium actively reabsorbed in the nephron? ANSWER: to decrease blood pressure to increase passive reabsorption of water to make urine less concentrated to decrease osmolarity inside the nephron
to increase passive reabsorption of water
Cell volume (and therefore cell function) in most cells is dependent upon careful regulation of ANSWER: resting membrane potential. permeability of cell membranes. osmolarity of extracellular fluid. blood pressure. volume of extracellular fluid.
urinary
The primary route for water loss from the body is the ________ system. ANSWER: digestive integumentary cardiovascular respiratory urinary
urinary
The two organ systems that work together to regulate most aspects of the body's water balance are ANSWER: urinary and cardiovascular. digestive and respiratory. digestive and cardiovascular. cardiovascular and respiratory. urinary and respiratory.
urinary and cardiovascular system
Respiratory Alkalosis
vomiting/increase ingestion of antiacids; normal/high CO2 = low H+ and high HCO3- = high pH
Kidneys regulate ANSWER: both water loss and gain. water gain only. water loss only
water loss only
When a body is dehydrated, water in the urinary bladder ANSWER: can be returned to the circulation directly. can be returned to the circulation after moving back into the kidneys. will still be expelled from the body in the urine.
will still be expelled from the body in the urine
if you increase CO2 levels...
you increase H+ (HCO3 goes up to, it is NOT buffereing a H+ - the H2CO3 is a buffered H+)
