WEEK 3 Flashcards
1
Q
what is the functional unit of kidney?
A
nephrons
2
Q
approximately, how many functional units are needed for the nephrons of each kidney?
A
1 to 1.5 million
3
Q
what are the main functions of the kidney
A
maintaining homeostasis, excretion of waste products, and maintenance of blood pressure and erythropoiesis
4
Q
the blood supplier of the kidney
A
renal artery
5
Q
the large blood flow percentage
A
25%
6
Q
what is the average body size?
A
1.73 mm2
7
Q
Process of renal blood flow
A
renal artery - afferent arteriole - glomerulus - efferent arteriole - peritubular capillaries - vasa recta - renal vein
8
Q
glomerulus is responsible for?
A
filtration
9
Q
vasa recta is responsible for?
A
water and salt exchange
10
Q
peritubular capillaries is responsible for?
A
immediate reabsorption
11
Q
makes up 85% of nephrons, primarily in the cortex of the kidney and is responsible for the removal of waste products and reabsorption of nutrients
A
cortical nephrons
12
Q
they have longer loops of henle, extending to deep part of medulla and responsible for concentration of urine
A
juxtamedullary nephrons
13
Q
what are the renal functions?
A
renal blood flow, glomerular filtration, tubular reabsorption, and tubular
secretion
14
Q
what part of the kidney is responsible for glomerular filtration?
A
glomerulus
15
Q
glomerulus consists of _____ of approximately ______ referred to as ______
A
coil, 8 capillary lobes, capillary tuft
16
Q
where is glomerulus located?
A
bowman’s capsule
17
Q
what is the molecular weight as a non-selective filter of plasma substances?
A
less than 700, 000
18
Q
factors that influence the actual filtration process
A
cellular structure of capillary walls and structure
hydrostatic and oncotic pressures
feedback of the renin-angiotensin-aldosterone system
19
Q
what are the cellular layers that plasma filtrate must pass through?
A
capillary wall membrane
basement membrane or basal lamina
visceral epithelium of bowman’s capsule
20
Q
capillary wall membrane contains ____ referred to as ____
A
pores, fenestrated
21
Q
the pores increase ____ but do not allow the passage of _______
A
capillary permeability, large molecules and blood cells
22
Q
in the basal lamina what process occurs as the filtrate passes through?
A
restriction of large molecules
23
Q
the thin membranes covering the ________ formed by the intertwining foot processes of the _______ of the ______
A
filtration slits, podocytes, inner layer of bowman’s capsule
24
Q
what pressure happens in the glomerular pressure
A
hydrostatic pressure
25
overcome the opposition of pressure from the fluid from the _____ and the ______ of unfiltered plasma protein
bowman's capsule, oncotic pressure
26
what mechanism maintains the glomerular blood pressure at constant rate regardless the fluctuations in systemic blood pressure?
autoregulatory mechanism
27
what part of the kidney does the autoregulatory mechanism happen?
juxtaglomerular apparatus
28
______ of the afferent arterioles and ______ of the efferent arterioles when blood pressure drops prevent a marked ________ in blood flowing through the kidney
dilation, constriction, decrease
29
when the blood pressure drops, what increase in the blood does this process prevents?
prevent an increase in blood level of toxic waste products
30
it controls the regulation of blood flow and within the glomerulus
raas - renin-angiotensin-aldosterone system
31
what changes does the system respond to?
changes in blood pressure and plasma sodium content
32
the system is monitored by which part?
juxtaglomerular apparatus
33
the juxtaglomerular consists of what?
juxtaglomerular cells in afferent arteriole
macula densa of distal convoluted tubule
34
low plasma sodium contents decreases ______ within circulatory system, resulting in _____
water retention, decreased overall blood volume and subsequent decrease in blood pressure
35
what is the enzyme produces by the juxtaglomerular cells
renin
36
renin is secreted with the blood-borne substrate ____ to produce the inert hormone ______
angiotensinogen, angiotensin I
37
what enzyme changes it to the active form of angiotensin II
ACE: Angiotensin-converting enzyme
38
which way does the angiotensin I passes through?
lungs
39
it corrects the renal blood flow
angiotensin II
40
what are the ways does angiotensin II corrects its renal blood flow?
- vasolidation of afferent
- vasoconstriction of efferent
- Sodium reabsorption in Proximal Convoluted Tubule
- Aldosterone release from the adrenal cortex
- Antidiuretic release from hypothalamus
41
when the systemic blood pressure and plasma sodium content ______, the secretion of renin ______
increase, decreases
42
Approximately _____ million glomeruli filter approximately _____ mL of water-containing low-molecular-weight substances every minute.
2-3, 120
43
Because this filtration is nonselective, the only difference between the compositions of the filtrate and the plasma is the ___________
absence of plasma protein
44
Analysis of the fluid as it leaves the glomerulus shows the filtrate to have a specific gravity of
1.010
45
The body cannot lose ____ mL of water-containing essential substances every minute
120
46
what are the 2 transports of the reabsorption mechanism?
active and passive
47
it is the plasma concentration at which active transport stops
renal threshold
48
the substance to be reabsorbed must combine to a ______ contained in the membranes of the
carrier protein, renal tubular cells
49
Active transport is responsible for the reabsorption of
- glucose, amino acids, and salts in the proximal convoluted tubule
- chloride in the ascending loop of Henle
- sodium in the distal convoluted tubule
50
the substances, glucose, amino acids, and salts are located in?
proximal convoluted tubule (PCT)
51
sodium is located in?
proximal and distal convoluted tubule
52
it is the movement of molecules across a membrane result of differences in their concentration or electrical potential on opposite sides of the membrane
passive transport
53
what are the physical differences?
gradients
54
what happens when the renal threshold of substances exceeds?
maximal reabsorptive capacity of tubules is affected
55
what appears when the renal threshold exceeds?
appearance of the substance in the urine
56
Passive reabsorption of water takes place in all parts of the nephron except
ascending loop of Henle
57
why does the reabsorption of eater does not take place in the ascending loop of Henle?
the walls of which are impermeable
to water
58
the substance, water is located in?
Proximal Convoluted Tubule
Descending loop of Henle
Collecting Duct
59
the substance, urea is located in?
Proximal Convoluted Tubule
Ascending loop of Henle
60
the substance, Sodium is located in?
Ascending loop of Henle
61
where does the tubular concentration begin?
descending and ascending loop of henle
62
water is removed by ______ in the descending loop of Henle, and _______ and_____ are reabsorbed in the ascending loop
osmosis, sodium and chloride
63
what is the selective reabsorption process?
countercurrent mechanism
64
what does the mechanism (countercurrent) maintain
osmotic gradient of the medulla
65
Maintenance of the osmotic gradient is essential for the _____ concentration of the filtrate when it reaches the _______
final, collecting duct
66
The final concentration of the filtrate through the _______ of water begins in the _____________ and continues in the __________
reabsorption, late distal convoluted tubule, collecting duct
67
reabsorption depends on what hormone?
vasopressin (ADH)
68
what part of the kidney does reabsorption depend?
osmotic gradient in medulla
69
production of vasopressin is determined by what state?
state of body hydration
70
A high level of ADH _____ permeability, resulting in _____ reabsorption of water, and a ____ -concentrated urine
increases , increased, low
71
___ Body Hydration - ↓ADH - ___ Urine Volume
↑↑
72
↓Body Hydration - __ ADH - ↓Urine Volume
↑
73
what are the 2 main functions of tubular secretion?
- elimination of waste products not filtered by the glomerulus
- regulation of acid-base balance
74
Tubular secretion involves the passage of substances from the _____ in the _______ to the ________
blood, peritubular capillaries, tubular filtrate
75
what are examples of foreign substances that cannot be filtered by the glomerulus?
urea and medications
76
why can't they be filtered by the glomerulus
because they are bound to plasma proteins
77
what is the normal blood pH?
7.4
78
the buffering capacity of the blood depends on what ions?
bicarbonate ions
79
what does the bicarbonate ions do?
they act as buffer to maintain the proper pH of the blood
80
the blood must buffer and eliminate the ______ formed by dietary intake and body metabolism
excess acid
81
secretion of hydrogen ions by the ________ into the filtrate prevents the
_________ from being excreted in the urine and causes the return of a bicarbonate ion to the _____.
renal tubular cells, filtered bicarbonate, plasma
82
In the proximal convoluted tubule, ______ is produced from the breakdown of the amino acid glutamine.
ammonia
83
a disruption in these secretory functions can result in ___ and its inability to produce an acid urine
metabolic acidosis or renal tubular acidosis
84
it is the standard tests used to measure the filtering capacity of the glomeruli
clearance test
85
it measures the rate at which the kidneys are able to _____ (to clear) a ______ from the blood
remove, filterable substance
86
what filtration rate does the clearance test measures?
glomerular filtration rate
87
The substance analyzed must be one that is neither ____________ by the tubules.
reabsorbed nor secreted
88
Factors to consider in the selection of a clearance test substance
- stability of the substance in urine during 24-hour urine collection
- consistency of the plasma level
- substances availability to the body
- availability of tests for analysis of substance
- reported in mL / min
89
it is the standard method for GFR
urea clearance test
90
what percentage of the filtered urea is reabsorbed?
40%
91
patients were hydrated to produce a urine flow of ___ mL/min
2
92
use of urea as a test substance for glomerular filtration has been replaced by the measurement of other substances including _____
creatinine, inulin, beta2 microglobulin, cystatin C, or radioisotopes
93
about ___ of creatinine clearance
50%
94
it is a polymer of fructose and is an extremely stable substance that is not reabsorbed or secreted by the tubules
inulin
95
was the original reference method
for clearance tests, it is currently not used for glomerular filtration testing.
inulin clearance test
96
not routinely done because of the necessity for continuous _____
IV infusion
97
Why are values higher in males?
Larger renal mass
98
what is the priming dose?
25 mL of 10% inulin solution
99
what is the continuous infusion?
500 mL of 1.5% inulin solution
100
What is the reference values for male?
127 mL / min
101
What is the reference values for female?
118 mL / min
102
this test requires an infused substance that is termed ____
exogenous procedure
103
is seldom the method of choice if a suitable test substance is already present in the body
endogenous procedure
104
a waste product of muscle metabolism which is normally found at a relatively constant level in the blood and provides the laboratory with an endogenous procedure for evaluating glomerular function
creatinine
105
it is the most commonly used screening method for GFR
creatinine clearance test
106
Measurement of creatinine clearance is not a reliable indicator in patients suffering from ________ diseases
muscle-wasting
107
creatinine is freely filtered by the _____ but not _____
glomerulus, reabsorbed
108
reference value for males?
85 - 125 mL / min
109
reference value for females?
75 -112 mL / min
110
what is the standard body surface?
1.73
111
UC stands for?
urine crea
112
UV stands for?
urine volume
113
PC stands for?
plasma crea
114
how many minutes?
1140 mins
115
What is the significance of GFR?
determines the functional capacity of nephrons
116
significance of Creatinine clearance
- extent of nephron damage in known cases of renal disease
- feasibility of administering medications
117
disadvantages of CCT
- Some creatinine is secreted by tubule
- chromogens - human plasma
- medications - false decreased value
- creatinine breakdown by bacteria
heavy diet
118
Average body surface?
1.73 mm2
119
approximate amount of plasma filtrate
120 mL
120
normal creatinine clearance values
120 mL / min
121
men creatinine values
107 - 139 mL / min
122
women creatinine values
87 - 107 mL / min
123
normal reference range of plasma creatinine
0.5 - 1.5 mg / L
124
it is indirect estimate of GFR and a low molecular weight protease inhibitor
Cystatin C
125
Cystatin is good procedure for?
Screening and monitoring GFR
126
What specimen is being used in Cystatin C
Serum or plasma
127
TRUE OR FALSE: Fasting is required in Cystatin C
False, it is not required
128
What diseases are associated when there are increased levels of Cystatin C?
Acute and Chronic Renal Failure
Diabetic nephropathy
129
It dissociates from human leukocyte antigens at constant rate
Beta 2 Microglobulin
130
What type of filtration happens in Beta 2 Microglobulin?
Glomerular filtration by plasma
131
TRUE OR FALSE: Beta 2 Microglobulin is reliable for patients who have immunologic disorders
False
132
What method is being used in Beta 2 Microglobulin?
EIA
133
It is used for routinely screening patients as part of a metabolic profile
Estimated Glomerular Filtration Rates
134
What type of patients are being monitored in eEGFR test?
patients diagnosed with renal disease or at risk
135
It utilizes additional variables
and does not include body weight.
Modification of Diet in Renal Disease (MDRD)
136
MDRD-ISMS stands for?
MDRD- Isotope dilution mass spectrometry
137
NKDEP?
National Kidney Disease Education Program
138
What description is at stage 3 of Chronic Kidney Disease
Moderate ↓ GFR
139
What GFR is at stage 3 of Chronic Kidney Disease
30-59
140
What description is at stage 5 of Chronic Kidney Disease
Kidney Failure
141
What GFR is at stage 5 of Chronic Kidney Disease
less than 15 or Dialysis
142
What description is at stage 1 of Chronic Kidney Disease
Kidney Damage with normal or ↑GFR
143
What GFR is at stage 1 of Chronic Kidney Disease
≥ 90
144
What description is at stage 4 of Chronic Kidney Disease
Severe ↓ GFR
145
What GFR is at stage 4 of Chronic Kidney Disease
15-29
146
What description is at stage 2 of Chronic Kidney Disease
Kidney Damage with Mild or ↓ GFR
147
What GFR is at stage 2 of Chronic Kidney Disease
60-89
148
Ability of the tubules to reabsorb the essential salts and water
Concentration test
149
What are the tests used for the Specific Gravity?
Fishberg and Mosenthal Test
150
It compares the volume and specific gravity of day and night urine samples
Mosenthal Test
151
Patients were deprived of fluids for 24 hours prior to the specific measures needed
Fishberg Test
152
It is affected only by the number of particles present.
Osmolarity
153
Renal concentration is concerned with small particles, s_________ and c_______ molecules
sodium, chloride
154
Large molecular weight molecules such as _____ and ________
glucose and urea
155
156
specific gravity is influenced by ____ and _____ (molecular weight) of particles
number, density
157
What is the principle of Freezing Point Osmometers
Measurement of freezing point depression
158
What is the principle of Vapor Pressure Osmometer?
Measures the drew point
159
What is drew point?
Temperature at which water vapor condenses to a liquid
160
Temperature at which water and ice are in equilibrium and related to solute concentration
Freezing point
161
What is the standard reference for Freezing point and Vapor pressure osmometers
NaCL (Sodium)
162
Tests to measure tubular secretion of nonfiltered substance and renal blood flow
P-aminohippuric acid (PAH) test
163
what can cause an abnormal result?
- Impared tubular secretory
- inadequate presentation of substance to capillaries
164
The ability of the kidney to produce an acid urine depends on the tubular secretion of hydrogen ions and production and secretion of ammonia by the cells of the distal convoluted
tubule.
Titratable acidity and Urinary ammonia
165
FILL IN THE BLANKS: A normal person excretes approximately ____ mEq/day
of acid in the form of either _______ (H+), _______ (H2PO4-), or ______ (NH4+)
70, titratable acid, hydrogen phosphate ions, ammonium ions
166
What time range does alkaline tides appear?
2 - 8 pm
167
What time of the day is the lowest pH?
Night
168
the inability to produce an acid urine in the presence of metabolic acidosis
Renal Tubular Acidosis
169
This condition may result from impaired tubular secretion of _______ associated with the __________
hydrogen ions, proximal convoluted tubule
170
This condition may also defect in _________ secretion associated with the ________
ammonia, distal convoluted tubule
