(Important note: this is NOT necessarily a complete list of possible topics or questions that can be asked, but just a guide to a large part of important information covered in the objectives.)
Lecture Module B-7 Urinary System Review Questions
Objective 1 - Introduction
1. What are the three major functions of the urinary system?
The three major functions are excretion, elimination, and homeostatic functions.
2. What are excretion and elimination?
Excretion is removal of organic wastes from body fluids, and elimination is discharge of waste products (through urination).
3. Name the homeostatic functions of the urinary system.
Regulating blood volume and blood pressure (essentially fluid balance), regulating plasma ion concentration (essentially solute balance), stabilizing blood pH (essentially acid-base balance), conserving nutrients, and assisting in detoxification.
Objective 2 - Renal Corpuscle Physiology
4. What is a glomerulus?
A special ball of capillaries that make up part of the renal corpuscle.
5. What cells support the glomerulus?
Special supporting cells known as mesangial cells. They are smooth muscle cells.
6. The lining of the outer glomerular capsule is ______ squamous epithelium.
simple
7. ______ are large inner visceral epithelium “foot” cells that cover glomerular capillaries.
Podocytes
8. The “feet” of podocytes are ______.
pedicels
9. How many layers is the filtration membrane in the renal corpuscle?
three
10. Name the layers of the renal filtration membrane.
Glomerular capillary endothelium, lamina densa, and (filtration slits of) podocytes.
11. ______ is an important passive physiological process that occurs in the renal corpuscle.
Filtration
12. Are plasma proteins in the filtrate?
no
Objective 3 - Renal Tubule Physiology
13. What are three functions of the renal tubule?
Reabsorption of nutrients, reabsorption of water, and secretion of wastes.
14. Name the three parts of the renal tubule.
proximal convoluted tubule
nephron loop
distal convolution tubule
15. The proximal convoluted tubule mainly functions in ______.
reabsorption
16. How many limbs does the nephron loop contain? Name them.
two; descending limb & ascending limb
17. Overall, in the nephron loop the water movement helps ______ tubular fluid.
concentrate
18. Name three functions of the distal convoluted tubule.
Secretion of ions, acids, drugs, toxins, reabsorption of water, reabsorption of sodium/calcium
19. What does the juxtaglomerular complex (JGA) release? What will this tend to do to red blood cells count and blood pressure?
The JGA releases erythropoietin and renin. This will tend to increase RBC count and increase blood pressure via the renin-angiotensin-aldosterone system.
Objective 4 - Collecting System
20. Individual nephrons drain into a nearby ______.
collecting duct
21. Collecting ducts converge into a ______.
papillary duct
22. Microscopic collecting ducts determine final osmotic ______ and ______ of urine.
concentration; volume
Objective 5 - Waste Products
23. How is urea formed?
Urea is formed through amino acid breakdown.
24. How is creatinine formed?
Creatinine is generated in skeletal muscle through breakdown of creatine phosphate.
25. How is uric acid formed?
Uric acid is formed via recycling of RNA nitrogen bases.
Objective 6 - Filtration, Reabsorption, Secretion
Filtration, Reabsorption, Secretion
26. Kidneys usually produce ______ urine. Failure to concentrate potentially leads to ______.
concentrated; dehydration
27. What are the three basic processes of urine formation?
filtration, reabsorption, secretion
28. Where does filtration take place?
renal corpuscle
29. Where do reabsorption and secretion take place?
renal tubule
30. Is filtration a passive process? What “fits” through the filtration membrane?
yes; small solutes
31. If proteins are restricted at the filtration membrane, should proteins normally be found in the urine?
no
32. What sort of transport processes are involved in reabsorption and secretion?
both active and passive; diffusion, osmosis, carrier-mediated transport
33. Does reabsorption move “stuff” OUT of the renal tubule into the bloodstream or INTO the renal tubule from the bloodstream?
Reabsorption moves stuff OUT of the renal tubule. It “reclaims” substances.
34. Does secretion move “stuff” OUT of the renal tubule into the bloodstream or INTO the renal tubule from the bloodstream?
Secretion moves stuff INTO the renal tubule from the bloodstream.
Transport Maximum/Renal Threshold
35. Can renal carrier proteins become saturated?
Carrier proteins can become saturated.
36. If ______ concentrations rise in tubular fluid, reabsorption rates increase until carrier proteins are saturated.
solute
37. If concentration is higher than the ______, that exceeds the reabsorptive abilities of the nephron.
transport maximum
38. The ______ is the plasma concentration at which a specific compound begins to appear in urine.
renal threshold
39. Having glucose in the urine is ______.
glycosuria
40. Is it normal for amino acids to commonly appear in the urine?
yes, after a protein-rich meal
Tubule Locations
41. Where does water and solute reabsorption primarily take place?
proximal convoluted tubule
42. Secretion occurs primarily at the ______ and ______ convoluted tubules.
proximal; distal
Nephron Types
43. Name the two nephron types.
cortical, juxtamedullary
44. What percentage are cortical nephrons?
85%
45. A ______ nephron is long and functions in water conservation (forming concentrated urine).
juxtamedullary
Osmolarity
46. What is osmolarity? It can be expressed as total number of ______ particles per ______.
solute; liter
Objective 7 - Pressure and Glomerular Filtration Rate
47. Filtration pressure is the ______ pressure forcing out water and dissolved materials.
average
48. Glomerular hydrostatic pressure is ______ than normal capillaries. Why?
higher; High pressure is needed to force blood into efferent arterioles.
49. ______ is the amount of filtrate kidneys produce each minute.
Glomerular filtration rate (GFR)
50. What is purpose of a creatinine clearance test?
It is used to estimate glomerular filtration rate.
GFR Control
51. Name the three controls of glomerular filtration rate (GFR) at the kidney.
autoregulation, hormonal regulation, autonomic regulation
52. Reduced renal blood flow/pressure will trigger dilation of ______.
afferent
53. Increased renal blood flow/pressure will trigger constriction of ______.
afferent
54. Autoregulation maintains ______ despite changes in local blood pressure/flow.
GFR
55. Hormonal regulation of GFR is mainly via ______.
renin-angiotensin-aldosterone system
56. Decline in ______ pressure is one factor that can cause release of renin by the JGA.
blood
57. Renin causes activation of ______.
angiotensin II
58. Angiotensin II will tend to ______ efferent arterioles of a nephron.
constrict
59. Angiotensin II will tend to stimulate secretion of ______ and ______ hormone.
aldosterone; antidiuretic hormone
60. Renin also stimulates the ______ nervous system, which increases cardiac output.
sympathetic
Objective 8 - Hormones, Diuresis, Review
61. Aldosterone stimulates synthesis of sodium channels along the ______ and ______.
distal convoluted tubule; collecting duct
62. Natriuretic (ANP & BNP) peptides ______ the secretion of aldosterone.
oppose
63. The actions of aldosterone and ADH are both suppressed by ______ peptides.
natriuretic
64. ADH ______ rate of osmotic water movement into the bloodstream.
increases
65. What is diuresis?
elimination of urine
66. Summarize renal function focusing on steps of filtrate/urine formation and modification.
glomerulus - produces filtrate
PCT - reabsorption of water, organic substances, ions
nephron loop - concentration of filtrate
DCT - final adjustments to filtrate; reabsorption or secretion
collecting ducts - final adjustments to filtrate; ADH can have an effect here
vasa recta - absorbs solutes, maintains concentration gradient of medulla
Objective 9 - Micturition Reflex
67. Urination is also called ______.
micturition
68. Describe the process of the micturition reflex.
detrusor muscle contraction, voluntary relaxation of external urethral sphincter causes relaxation of internal urethral sphincter
69. Do infants have voluntary control of urination?
no
70. ______ is the inability to control urination voluntarily.
incontinence
71. Name some age-related changes in the urinary system.
decline in functional nephrons
reduction of GFR
reduced sensitivity to ADH
Objective 10 - Fluid, Electrolyte, Acid-Base Balance
72. Name the two main fluid (water) compartments in the body.
intracellular fluid (ICF), extracellular fluid (ECF)
73. How much volume does intracellular fluid (ICF) occupy?
2/3
74. What percentage of extracellular fluid (ECF) volume is interstitial fluid?
80%
75. Body weight is ______% water.
60
76. In plasma, what is the chief cation and anion?
In plasma, sodium is the chief cation and chloride is the chief anion.
77. In ICF, what is the chief cation and anion?
In ICF, potassium is the chief cation and phosphate is the chief anion.
78. ______ make up 90% of the mass of solutes in plasma.
Proteins
79. ______ make up 97% of the mass of solutes in intracellular fluid.
Proteins
Proper Composition of Fluids
80. To survive, we must maintain the proper ______ and ______ of ICF/ECF.
volume; composition
81. Name the three factors that must be balanced in order to maintain proper ICF/ECF composition.
fluid, electrolyte, acid-base
82. What body system is involved in gaining water? Losing water?
The digestive system is the main way of getting water, and the urinary system is the main way of losing water.
83. What body system is involved in electrolyte absorption? Excretion?
The digestive system is the main way of absorption, and the urinary system is the main way of excretion.
84. What two body systems are involved in balancing acids and bases?
The urinary system plays a role by secreting hydrogen ions and buffers into the bloodstream, and the respiratory system plays a role by eliminating carbon dioxide.
Hormones
85. Name two major effects of ADH.
(1) causes kidneys to conserve water
(2) stimulates thirst center in hypothalamus
86. Name three stimuli that cause release of aldosterone.
(1) rising potassium in bloodstream
(2) falling sodium in bloodstream
(3) activation of renin-angiotensin-aldosterone system
87. Name two major effects of atrial natriuretic peptide (ANP).
(1) reduces thirst
(2) blocks release of ADH and aldosterone
Sources/Losses
88. What sources give us most water?
60% via fluid, 30% via solid food, 10% via metabolism
89. 60% of our water output is through ______.
fluid
90. Sodium functions as a water “______” in the kidneys.
magnet
91. Name some electrolyte and nonelectrolyte solutes. Which have greater osmotic power? Why?
electrolytes: salts, acids/bases, proteins
nonelectrolytes: glucose, lipids, creatinine
Electrolytes have greater osmotic power, due to charge.
92. Electrolyte balance is another name for ______ balance.
salt
Summary Concepts
93. All mechanisms that adjust body fluid respond to ______ changes only.
extracellular fluid (ECF)
94. No receptors directly monitor specific fluid or ______ balance.
electrolyte
95. Can cells move water via active transport?
no
96. If dietary gains of water exceed environmental losses, water content will ______.
increase