WEEK 1 (Chapter 4) Flashcards
1
Q
Functions of Kidneys
A
- Excrete waste products of metabolism
- Regulate Blood Pressure
- Regulate acid-base balance
- Regulate electrolyte balance
- Regulate RBC production
2
Q
Waste products of metabolism
A
- creatinine
- urea
3
Q
These are toxic to RBCs
A
- creatinine
- urea
4
Q
Waste product of muscle metabolism
A
Creatinine
5
Q
Waste product of protein metabolism
A
Urea
6
Q
Tested by BUN
A
Urea
7
Q
BUN test meaning
A
Blood Urea Nitrogen
8
Q
Organs involved in regulating acid-base balance
A
- lungs
- kidneys
9
Q
Excretes H+ ions to the renal tubules to be excreted as urine
A
Kidney
10
Q
Ideal blood pH
A
7.35 - 7.45
11
Q
Blood pH decreases
A
Acidosis
12
Q
Blood pH increases
A
Alkalosis
13
Q
Triggers of RAAS
A
- Low Na
- Low BP
- Low water volume
14
Q
Triggered when kidney releases renin
A
RAAS
15
Q
Hormone released by the kidney that promotes RBC production
A
Erythropoietin (EPO)
16
Q
Blood flow in the kidney
A
17
Q
Basic functional unit of kidneys
A
Nephron
18
Q
How many nephrons per kidney?
A
1-1.5M (2-3M both kidneys)
19
Q
Types of Nephron
A
- Cortical
- Juxtamedullary
20
Q
Present in renal cortex only
A
Cortical
21
Q
Forms 85% of nephrons
A
Cortical
22
Q
Type of nephron where removal of waste product takes place
A
Cortical
23
Q
Type of nephron where reabsorption takes place
A
Cortical
24
Q
Loops of henle extends to the renal medulla
A
Juxtamedullary
25
Type of nephron where concentration of urine takes place
Juxtamedullary
26
Part of nephron that acts as a sieve
Glomerulus
27
Found in the renal cortex
Cortical and Juxtamedullary nephrons
28
Found in the renal medulla
Loop of henle
29
Total renal blood flow
1200 mL/min
30
Component of total renal blood flow
Whole blood
31
Total renal plasma flow
600-700 mL/min
32
Amount that becomes filtrate
* not the final volume of urine
120-130 mL/min
33
According to Strasinger, what MW cannot be filtered by glomerulus? (Clinical Microscopy/AUBF)
< 70,000
34
According to Bishop, what MW cannot be filtered by glomerulus? (CC)
>66,000
35
Urine formation process
1. Filtration
2. Reabsorption
3. Secretion
36
Filtrate going back to the blood vessels
Reabsorption
37
Path for reabsorption
Renal tubules to peritubular capillaries
38
Path for secretion
Peritubular capillaries to renal tubules
39
Pathway of filtrate
Bowman’s Capsule > PCT > Descending Loop of Henle > Ascending Loop of Henle > DCT > Collecting Duct (renal pelvis to ureter to urinary bladder to urethra)
40
Factors that influence glomerular filtration process
- cellular structure
- pressure
- RAAS
41
Endothelial Cell
Capillary wall membrane
42
Contain numerous pores (fenestrated)
Capillary wall membrane
43
Prevents filtration of protein
GBM
44
Negatively charged
GBM and Protein
45
Happens when neg charge and another neg charge meet
Repel
46
Podocytes
Visceral epithelium
47
Slit membranes prevents filtration of protein
Visceral epithelium
48
Types of pressure in glomerular filtration
- hydrostatic
- oncotic
49
Forces fluid out of vessel
Hydrostatic
50
Maintains fluid inside the vessel
Oncotic Pressure
51
Constriction of EFFERENT ARTERIOLE
- Increased Hydrostatic Pressure
- Increased GFR
52
Constriction of AFFERENT ARTERIOLE
- decreased hydrostatic pressure
- decreased GFR
53
RAAS meaning
Renin- angiotensin-aldosterone system
54
Receives/senses the start of RAAS
Macula densa cells
55
Process of RAAS
Triggers > Macula densa cells > JG cells to release renin (from kidney) > angiotensinogen (from liver) > angiotensin I > angiotensin II (by angiotensin-converting enzymes/ACE)
56
Controls the regulation of the flow of blood to and within the kidneys
RAAS
57
Inactivated angiotensin
Angiotensin I
58
Activated Angiotensin
Angiotensin II
59
Specific gravity of filtrate
1.008-1.010
60
Specific gravity of urine
1.035
61
pH of filtrate
7.4
* higher value indicate old specimen
62
Major reabsorption site
PCT
63
plasma concentration of a substance at
which active transport stops and increased amounts are excreted in the urine
Renal threshold
64
Example of renal threshold
Glucose Renal threshold
65
Amount of glucose reabsorbed back to the body
Glucose renal threshold
66
Range of glucose renal threshold
160-180 mg/dl
67
Frequent urination
Polyuria
68
What is reabsorbed by PCT?
Water, Na+ (65%), K+, glucose, amino acids (100%), vitamins, chloride, urea (50%), HCO3 (80-90%)
69
A substance combines with carrier protein
Active Transport
70
Electrochemical energy transfers the substance across the cell membrane
Active transport
71
Vessels of active transport
Renal Tubules and Blood Vessels
72
Differences in their concentration or electrical potential on opposite sides of the membrane
Passive transport
73
Hairpin-like loop
Loop of Henle
74
Important in regulating osmolarity of the medullary interstitial fluid
Loop of Henle
75
System of loop of henle
Countercurrent Multiplier System
76
Very permeable with water
Descending limb
77
Impermeable to water
Ascending limb
78
What is/are absorbed by the ascending loop of henle?
Na+ and Cl-
79
Reabsorption depends on what?
Osmotic gradient in medulla and vasopressin (ADH)
80
High ADH
⬆️ permeability
⬆️ reabsorption of water
⬇️ low-volume urine (concentrated)
⬇️ body hydration
81
Low ADH
impermeable to water
large volume of urine
⬆️ body hydration
82
Passage of substances from the blood in the peritubular capillaries to the tubular filtrate
Tubular Secretion
83
Elimination of waste products not filtered by glomerulus
Tubular Secretion
84
Responsible for urine acidity
H+ ion
85
Regulation of acid-base balance
Tubular Secretion
86
Acidic blood; alkaline urine
Renal tubular acidosis
87
Buffers H+ ions
Phosphate or ammonia
88
Buffered H+ excreted in urine in form of:
- ammonium ions
- dihydrogenphosphate
- weak organic acids
89
reflects the ability of the kidney to maintain normal hydrogen ion concentration in plasma and extra cellular fluid
pH
90
_ must buffer and eliminate excess acids
Blood
91
Buffering capacity of blood depends on ___.
Bicarbonate ions (HCO3-)
92
Is proximal convoluted tubule exclusively for reabsorption?
No, because there are substances secreted from PCT.
93
Test used in measuring GFR
Clearance Test
94
_ Measures the _ at which the kidneys can remove or clear a filterable substance from the blood
Clearance Test; rate
95
Unit for clearance test
mL/min
96
Removal of a substance from plasma into urine over a fixed period
Clearance test
97
Not bound to proteins
Marker
98
Filtered, neither reabsorbed nor secreted
Marker
99
Types of markers
- exogenous substance (administered)
- endogenous substance (found in body already)
100
High clearance test : _ GFR : _
High GFR; Efficient excretion
101
Low clearance test : _ GFR : _
Low GFR; Inefficient excretion
102
Sample for clearance test
24 hr sample
103
Tells body surface area of patient
Nomogram
104
Average body surface area
1.73m^2
105
State each part of nomogram and for what area
Left:height
Middle:weight
Right:where height and weight are aligned
106
Administered to the body
Exogenous
107
Reference method
Inulin
108
Old method
Inulin
109
Soluble, freely filtered, neither secreted nor reabsorbed
Inulin
110
Not routinely done; can be invasive
Inulin and radioactive markers
111
Normal values for male (inulin)
127 ml/min/1.73m^2
112
Normal values for female
118 ml/min/1.73m^2
113
Naturally produced in the body
Endogenous
114
Minimally secreted in PCT
Creatinine
115
Most widely used marker for GFR
Creatinine Clearance
116
Normal values for male (creatinine clearance)
85-125 ml/min
117
Normal values for female (creatinine clearance)
75-112 ml/min
118
Greatest source of error in any clearance procedure using urine
Improperly timed urine specimen
119
MDRD-IDMS is recommended by who?
National Kidney Disease Education Program (NKDEP)
120
Most recent test and what year
Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI); 2021
121
Depends on the number of functioning nephrons and the functional capacity of these nephrons
GFR
122
Cannot provide actual concentrating ability of tubules
Specific gravity
123
Used as a screening test
Specific gravity
124
Ratio of density of a substance to that of another substance (commonly water)
Specific gravity
125
Used to know actual renal concentration ability
Osmometry
126
Obsolete tests
- fishberg
- mosenthal
127
Patients are deprived of fluids for 24 hrs prior to measuring the specific gravity
Fishberg test
128
Compares the volume and specific gravity of day and night samples
Mosenthal Test
129
Quantifies the number of particles in the solution
Osmolality
130
More of a diagnostic test and much better than specific gravity
Osmolality
131
Measurement of freezing point depression
Freezing point osmometer
132
Freezing point depression is _ proportional to the amount of solute present in the solution
Directly
133
Unit for freezing point osmometer
mOsm/Kg
134
Vapor pressure depression
Vapor depression osmometers
135
The depression of dew point temperature by solute parallels the decrease in vapor pressure
Vapor pressure osmometers
136
Magnitude of the vapor pressure decrease is _ proportional to the molar concentration of solute
Vapor Pressure Osmometers
137
Values Range of osmolality
50-1400 mOsm
138
- Presence of ADH
- Kidneys are unresponsive to ADH
- May have problems with receptors
Nephrogenic DI
139
- Absence of ADH
- Hypothalamus is not triggered to activate ADH
- Unproduced
Neurogenic DI
140
The amount of solute-free water excreted per day.
Free water clearance
141
Indicates how much water must be cleared each minute to produce a urine with the same osmolarity as the plasma
Osmolar clearance
142
Less than the necessary amount of urine is excreted
Negative Result
143
Urine is more concentrated than the plasma
Negative Results
144
Excess water is excreted
Positive Results
145
Kidney is producing dilute urine through the excretion of solute-free water
Positive Results
146
Not normal
Free Watermelon Clearance is 0
147
Tubules have no capacity to be able to concentrate urine
Free water clearance is 0
148
Osmolarity of urine is equal to plasma
Free water clearance is 0
149
Tubular Secretion and Renal Blood Flow Tests
- P-aminohippuric Clearance Test (PAH)
- Titrable and Urinary Ammonia
- Phenolsulfonphthalein Test (PSP)
150
Dye excretion Test; exogenous
Phenolsulfonthalein Test (PSP)
151
Measures urinary ammonia; most used test; endogenous
Titrable Acidity and Urinary Ammonia
152
_ determines the amount of H+ ions in urine
Titration
153
- Actively secreted into the tubule
- exogenous test
- Loosely bound plasma proteins
- Permits its complete removal as the blood passes through the peritubular capillaries
P-aminohippuric Clearance Test (PAH)
