Renal I Flashcards
(122 cards)
1
Q
T/F: Renal function is dynamic (constantly changing).
A
True
2
Q
What are the two major functions of the kidneys?
A
- Regulation of water/salt balance
2. Removal of metabolic waste, drugs, other chemicals
3
Q
What are two secondary functions of the kidneys?
A
- Gluconeogenesis
2. Produce hormones - erythropoietin, renin, 1,2,5 dihydroxyvitamin D
4
Q
T/F: The kidney directly filters the majority of the water in the body.
A
False
Very small amount but affects the other compartments
5
Q
T/F: Acute end stage renal disease requires hemodialysis.
A
False
Chronic
6
Q
ESRD patients have a reduced ability to eliminate __________ and excess nitrogen is converted to ________.
A
nitrogenous waste (urea); ammonium
7
Q
What happens as a result of excess ammonium?
A
Blood is alkalized -> increased pH in the oral cavity
8
Q
What are some manifestations of renal disease in oral health?
A
- Ammonia breath
- Gingival enlargement
- Xerostomia
- Tooth problems: premature loss, narrow pulp, necrosis under fillings/crowns
9
Q
What are some contraindications for ESRD patients?
A
- Nephrotoxic drugs
2. Increased bleeding
10
Q
The kidney consists of an outer ________ and an inner _______.
A
cortex; medulla
11
Q
What is the functional unit of a kidney?
A
Nephron
12
Q
The cortex is made up of mostly _______, while the medulla contains more _______.
A
glomeruli; tubules
13
Q
What happens to blood in the cortex?
A
Blood is filtered
14
Q
What happens in the renal medulla?
A
concentration and collection of urine
15
Q
The renal corpuscle is made of the ________ and the ________.
A
glomerulus and capsule
16
Q
What structures does the filtrate go through after exiting the renal corpuscle?
A
Proximal convoluted tubule -> Henle’s loop -> distal convoluted tubule -> collecting duct
17
Q
What are the two types of neurons that differ in their position and length?
A
- Superficial or cortical nephrons
2. Juxtamedullary nephrons
18
Q
What are the three renal processes?
A
- Filtration
- Secretion
- Reabsorption
19
Q
What is involved in the filtration process?
A
Water passes from blood into Bowman’s space -> water is filtered in glomerular capillaries
20
Q
How much of the plasma entering the glomerulus is filtered?
A
15-20%
21
Q
Where does the blood leaving the glomerular capillaries flow to?
A
Peritubular capillaries (vasa recta)
22
Q
Describe the process of secretion.
A
Substances transported from blood in peritubular capillaries into the tubular fluid
23
Q
During reabsorption substances are transported from __________ into the __________.
A
tubular fluid; blood in peritubular capillaries
24
Q
T/F: Secretion and absorption occur throughout the length of the tubules.
A
True
25
What happens to the remaining tubular fluid at the end of the collecting duct?
It is excreted
26
Filtration occurs in the _______ and collection of the filtrate occurs in the ________.
glomerulus; renal capsule
Together make up renal corpuscle
27
T/F: There is smooth muscle in the afferent and efferent arterioles to regulate blood flow through the glomerulus.
True
28
How does the juxtaglomerular apparatus (JGA) regulate kidney function?
Secretes renin which regulates blood pressure and therefor glomerular blood flow
29
T/F: Blood flow through the glomerulus is regulated by the sympathetic nervous system.
True
30
The proximal convoluted tubule drains the ________.
renal capsule
31
The distal convoluted tubule drains the _________.
loop of Henle
32
Where in the nephron do the strongest diuretics act?
loop of Henle
33
T/F: 2/3 of filtered salt and water will reabsorb in the proximal convoluted tubule.
True
34
Where is all filtered glucose and amino acids reabsorbed?
Proximal convoluted tubule
35
What are the three segments of the loop of Henle?
1. Thin descending limb
2. Thin ascending limb
3. Thick ascending limb
36
T/F: The loop of Henle produces a concentrated filtrate.
False
Dilute filtrate
37
Where in the nephron does the regulation of calcium take place?
Distal convoluted tubule
38
T/F: Each collecting duct collects fluid from a single nephron.
False
Collects from multiple nephrons
39
T/F: Sodium, potassium, and water are all regulated in the collecting duct.
True
40
What is renal clearance?
Rate of excretion of solute through the kidney/unit of time
41
_________ is the amount of blood that is filtered by the kidney.
Glomerular filtration rate (GFR)
42
What three criteria allow for renal clearance to be used to measure GFR?
1. Substance is freely filtered in glomerulus
2. Substance is not secreted
3. Substance is not reabsorbed
43
What are normal kidney GFR values in males and females?
Male: 90-140 ml/min
Female: 125 ml/min
44
______ and ______ can be used to measure renal clearance.
Insulin and creatinine
45
What do insulin and creatinine have in common that allow them to be used to measure renal clearance?
freely filtered, and not secreted or reabsorbed
46
If creatinine levels are greater than ___, the patient requires dialysis.
10
47
________ around the capillaries in the glomerulus form filtration slits.
Podocytes
48
T/F: Glucose, salts, and amino acids are freely filtered.
True
49
T/F: Filtrate is full of cells and protein.
False
50
T/F: Solutes over 42 A are not filtered.
True
51
T/F: If a solute is negatively charged, it is more easily filtered.
False
Negatively charged basal lamina can repel negatively charged solutes
52
Differences in ________ between the blood in capillaries and fluid in the capsule allows for filtration.
pressure
53
The hydrostatic pressure in the capillaries is _______ than that in the capsule.
greater
54
What is oncotic pressure?
Pressure due to solutes in fluid
55
The oncotic pressure in the capillaries is _______ than that in the capsule.
greater
56
T/F: Renal blood flow varies with systemic blood pressure changes.
False
Renal blood flow and GFR remain fairly constant
57
What are the two primary mechanisms for auto regulation of kidney function?
Myogenic and tubuloglomerular feedback
Both intrinsic
58
How does the myogenic mechanism regulate kidney function?
Constriction/dilation of afferent and efferent arterioles
59
How does the tubuloglomerular feedback system work?
Feedback from juxtaglomerular apparatus adjusts afferent arteriol diameter and thus GFR
60
T/F: An increase in GFR will increase NaCl in tubular fluid.
True
61
Describe the tubuloglomerular feedback loop.
Increase GFR -> increase in NaCl in tubular fluid and at macula dense -> increased resistance in afferent arterioles -> decrease in GFR
62
What are some extrinsic factors that regulate GFR and RBF?
1. Diet
2. Dehydration/hemorrhage
3. Symp nervous system
4. Angiotensin II, aldosterone, natriuretic peptide
63
What is the difference between trans cellular and paracellular transport in the tubules?
Transcellular: through tubular cells
Paracellular: between tubular cells
64
_________ results from solutes being carried by water in paracellular transport.
Solvent drag
65
The rate of osmosis in the tubules can be regulated by _______.
aquaporins
66
Where does the majority (50%) of sodium reabsorption happen?
Proximal tubule
67
Where does sodium reabsorption not occur?
Descending limb of loop of Henle
68
Glucose and amino acids are reabsorbed in the proximal tubule using ________.
symporters with Na+
69
How does the proximal tubule keep [Na+] low ?
Active transport on the basal side
70
How do water and solutes move in the proximal tubule?
Paracellular transport
71
Na+ reabsorption occurs in conjunction with ________ reabsorption using a _________.
bicarbonate; Na+/H+ antiporter
72
T/F: The proximal tubule has transporters for many organic anions and cations associated with many drugs.
True
Transporteres have low specificity and can be saturated
73
By the end of the proximal tubule, ____ of Na+, Cl-, and water are reabsorbed.
2/3
74
K+ and divalent cations are reabsorbed in the proximal tubule by _______.
Solvent drag
75
T/F: All amino acids and glucose are reabsorbed in the proximal tubule.
True
76
How is bicarbonate reabsorbed in the proximal tubule?
Na+/H+ transporter
77
In the loop of Henle, ____ of filtered NaCl and ____ of water is absorbed.
25%; 15%
78
T/F: The descending limb of the loop of Henle is permeable to salt, but impermeable to water.
False
Permeable to water, but impermeable to salt
79
T/F: Reabsorption in the descending and ascending thin limbs of the loop of Henle is passive.
True
80
In what part of the loop of Henle is fluid diluted?
Ascending thick limb
81
What molecules are pulled across the apical membrane via a symporter in the ATL?
Na+, 2Cl-, and K+
82
T/F: Paracellular transport of ions in the loop of Henle is due to solvent drag.
False
Cations diffuse along electrical gradient because tubular fluid becomes positive when Cl- is reabsorbed
83
T/F: Fluid leaving the loop of Henle is hyposmotic.
True
84
How is hyperosmotic urine formed?
Renal countercurrent mechanism establishes osmotic gradient to reestablish hyper osmotic urine in the collecting duct
85
Antidiuretic hormone will have effect on which part of the nephron?
Will cause more reabsorption of water in the collecting duct
86
What would happen in the collecting duct if ADH is not present?
Too much water will be excreted
87
T/F: Osmolarity of the blood leaving the kidney to the veins is normal.
True
88
About ___ of the filtered NaCl is reabsorbed in the initial distal tubule.
8%
89
About ___ of the filtered NaCl is reabsorbed in the late distal tubule and collecting duct together.
8%
90
T/F: Cells in the early distal tubule have s NaCl symporter in the apical membrane and a Na+ K+ ATPase in the basolateral membrane.
True
91
What are the two types of cells in the late distal tubule and collecting duct?
1. Principal cells: reabsorb Na+ and secrete K+
| 2. Intercalated cells: acid-base balance
92
Vasopressin/ADH is released from the _______.
Posterior pituitary
93
When is ADH stimulated?
1. High osmolality of body fluids
2. Decrease in blood volume
3. Decrease in blood pressure
94
Low pressure baroreceptors in the ________ and __________ respond to decrease in blood volume by stimulating ADH.
left atrium and large pulmonary vessels
95
High pressure baroreceptors in the _________ and _________ respond to a decrease in blood pressure by stimulating ADH.
aortic arch and carotid sinus
96
How does ADH stimulate the reabsorption of water into the blood?
Increases aquaporins in apical membrane of collecting duct
97
Diuresis (low ADH) would lead to _______ urine.
dilute
98
Antidiuresis (high ADH) would lead to ________ urine.
concentrated
99
What is the goal of the renin-angiotensin-aldosterone system?
Increase reabsorption of sodium and water
Combat volume contraction
100
What would stimulate the kidney to produce renin?
Low fluid volume in the nephron
1. Drop in perfusion pressure
2. Decreased NaCl delivery to macula densa
3. Symp input to JG cells
101
What does renin do?
Converts angiotensinogen to angiotensin I
102
What converts angiotensin I into angiotensin II?
ACE (happens in lungs)
103
What are the affects of angiotensin II?
1. Vasoconstriction
2. Release of ADH
3. Increase sympathetics
4. Aldosterone secretion
104
What is the result of aldosterone secretion?
NaCl and water resorption in the collecting duct -> increased blood pressure/volume
105
When are natriuretic peptides secreted?
When the heart dilates -> volume expansion
106
Atrial natriuretic peptides come from the _____, and brain natriuretic peptides come from the _______.
atria; ventricles
107
What are the effects of natriuretic peptides?
1. Vasodilation of afferent arterioles
2. Vasoconstriction of efferent arterioles
3. Inhibition of renin, aldosterone, and ADH
108
The net effect of natriuretic peptides is to _______.
increase the excretion of water -> lower BP/blood volume
109
Na+ resorption ill ______ BP, while Na+ secretion will ________ BP.
increase; decrease
Water will follow the solutes
110
What is euvolemia?
Normal blood volume
111
When attempting to lower blood volume due to volume expansion, where will the biggest effect take place?
Proximal convoluted tubule: drops from 2/3 NaCl reabsorption to 1/2
TAL and DT actually increase reabsorption
112
Hyperkalemia (too much K+) will _________ muscles.
depolarize
113
Hypokalemia will ________ muscles.
hyperpolarize
114
Changes in ___ can cause cardiac arrhythmias.
K+
115
Kidneys typically excrete _____ of ingested K+.
90-95%
116
T/F: Roughly 2/3 of K+ is reabsorbed in the proximal tubule.
True
Paracellular solvent drag
117
How is K+ reabsorbed in the thick ascending limb?
Na+K+Cl- symporter
Paracellular (not solvent drag)
118
Which cells in the distal tubule/collecting duct secrete K+?
Principal cells via ATPase
119
Which cells in the distal tubule/collecting duct reabsorb K+?
Intercalated cells
120
An increase in plasma K+ would stimulate _______ which activates principal cells.
aldosterone
121
Higher flow rate in the tubules would lead to an increase in Na+ ________ and an increase in K+ ________.
reabsorption; secretion
122
Where in the nephron is K+ regulation occurring?
distal tubule and collecting duct
