MTAP 1 Flashcards
Each kidney contains approximately how many nephrons
1 - 1.5 million nephrons
The kidneys receive approximately how many percent of blood from the heart.
25%
Carries blood TO the glomerulus
Afferent arteriole
Carries blood FROM the glomerulus
Efferent arteriole
Surrounds the PCT and DCT
Peritubular capillaries
Located adjacent to the Loops of Henle in the Juxtamedullary Nephrons
Vasa recta
TOTAL RENAL BLOOD FLOW
1200 mL/minute
TOTAL RENAL PLASMA FLOW
600-700 mL/minute/kidney
High Hydrostatic Pressure enhances
Glomerular Filtration
Location of Juxtaglomerular cells
Afferent arterioles
Location of Macula densa cells
Distal convoluted tubules
Stimulus of Juxtaglomerular cells
Low Blood Pressure
Stimulus of Macula densa cells
Low Plasma Sodium
Mechanisms of action of Angiotensin II to increase BP
Vasodilation of afferent arterioles and vasoconstriction of efferent arterioles
Stimulates reabsorption of Sodium in the PCT
Triggers the release of aldosterone and antidiuretic hormone
Removing the substances from the filtrate back to the blood
TUBULAR REABSORPTION
MAJOR SITE OF REABSORPTION
Proximal Convoluted Tubule (PCT)
Substances that are part of active transport
Glucose
Amino acid
Salts
Chloride
Sodium
Proximal Convoluted Tubule (PCT) reabsorbs what substances
Glucose
Amino acids
Salts
Ascending Loop of Henle reabsorbs what substance
Chloride
Distal Convoluted Tubule (DCT) reabsorbs what substance
Sodium
It uses carrier protein
Active transport
It uses a concentration gradient
Passive transport
GLUCOSE RENAL THRESHOLD
160-180mg/dL
what is the Ultrafiltrate specific gravity
SG: 1.010
Urine Concentration begins in
Descending and Ascending Loop of Henle
responds to the body’s need for sodium
produced and released from the adrenal cortex
promotes sodium reabsorption in the DCT and potassium secretion
Aldosterone
responds to the body’s state of hydration
produced in the hypothalamus
released by posterior pituitary gland
Anti-diuretic hormone/ADH/Vasopressin
Passage of substances from the blood to the filtrate for excretion
Tubular secretion
Major site of secretion
Proximal Convoluted Tubules (PCT)
Standard test used to measure the filtering capacity of the glomeruli by measuring the rate at which the kidneys are able to clear a filterable substance from the blood.
Clearance Test
In passive transport all parts of the nephron EXCEPT for Ascending Loop of Henle reabsorbs what substance
Water
In passive transport PCT and Ascending Loop of Henle reabsorbs what substance
Urea
In passive transport Ascending Loop of Henle reabsorbes what substance
Sodium
Medications that may cause a false increase in creatinine clearance
Gentamicin
Cephalosporin
Cimetidine (Tagamet)
Originally the reference method for clearance tests
Reference research method
Inulin clearance test
Is a polymer of fructose which is extremely stable.
Inulin
Other substances that may be used for clearance tests:
B2-macroglobulin
Cystatin C
Radioisotopes
The most frequently used formula for eGFR
Cockroi and Gault Formula
Cockroi and Gault Formula variables
Weight
Age
Sex
Modifica>on of Diet in Renal Disease (MDRD) System Formula variables
Albumin
BUN
Ethnicity
An advantage of using eGFR is its capability to be computed even without
Urine creatinine value
What are the 2 water deprivation test
Fishberg test
Mosenthal test
Normal SG and Osmolarity in Water Deprivation Test
> 1.025
800 mOsm
A test where a patient is deprived of fluid for 24 hours
Fishberg test
Has no importance to the evaluation
of renal concentration ability
Urea
Glomerular Filtration Test
Clearance Tests
Calculated GFR Estimates (eGFR)
Tubular Reabsorption and Concentration Tests
Fishberg
Mosenthal
Specific Gravity
Osmolarity
Tubular Secretion and Renal Blood Flow Tests:
PSP
PAH
60-90%: MAJOR ORGANIC component
Urea
MAJOR INORGANIC component
Chloride
Electrolytes concentration
Chloride>Sodium>Potassium
To verify that a specimen is a urine, test for the (organic contents).
Urea
Creatinine
Urine container volume for routine analysis
50mL
Urine volume on the container for routine analysis
12mL
Normal daily urine output
600 - 2000mL
Average urine output
1200 - 1500mLG
SG of random specimen
1.003 - 1.035
SG of 24 hour
1.015 - 1.025
Normal odor of urine
Aromatic
pH of random urine specimen
4.5 - 8.0
pH of first-morning urine specimen
5.0 - 6.0
pH of urine specimen normal protein diet
4.5 - 6.5
Normal urine protein
<10mg/dL or 100 mg/dL/24 hours
Normal urine glucose
15 mg/dL
Normal urine glucose (fasting)
2-20 mg/dL per 100mL of urine
Normal urobilinogen glucose
<1 mg/dL
Urine sample must be sent to the laboratory and tested within
2 hours
IF NOT PROPERLY PRESERVED, what parameters increases
pH
Bacteria
Odor
Nitrite
Most routinely used method of preservation
Refrigeration
PRESERVATION method that causes precipita>on of amorphous phosphates (white) and amorphous urates (pink)
Refrigeration
preserves glucose and sediments well
Thymol
preserves protein and formed elements wells. Can be used for culture transport.
Boric acid
Excellent sediment preservative. Preservative for Addis count
Formalin/formaldehyde
A preservative that does not interfere with routine tests and is not effective against bacteria
Toluene
prevents glycolysis; good preserva>ve for drug analysis
Sodium fluoride
causes an odor change
Phenol
preserves cellular elements, hence, used for cytologic studies
Saccomanno fixative
used on automated instruments
Yellow Plain UA tube
decreases pH. Sample is stable at room temperature for 48 hours.
Preservative is sodium propionate.
Gray C and S tube
stable for 72 hours at room temperature
Cherry red/yellow top tube
TYPES OF URINE SPECIMEN for routine testing
Random
Ideal specimen for routine UA and pregnancy test (hCG)
Most concentrated; most acidic: for cell preservation of cells and casts
For evaluation of orthostatic proteinuria
First morning
For glucose determination
Fasting
For diabetic screening/monitoring
2 hour postprandial
Optional with blood samples in glucose tolerance test
Glucose tolerance
For routine screening and bacterial culture
Midstream Clean Catch
For bacterial culture
Catheterized
Most sterile
Bladder urine for anaerobic bacterial culture and urine cytology
Suprapubic Aspiration
Use of soft, clear plastic bag with adhesive
Pediatric Specimen
For nitrite determination
4 hour timed specimen
Alkaline tide happens at what time
2-4pm
Specimen for addis count
12 hour timed specimen
Volume of Urine Specimen for Drug Analysis
30-45mL
temperature of Urine Specimen for Drug Analysis
32.5 – 37.7C
32.5 – 37.7C is taken within
4 minutes
Oliguria on Infant
<1mL/kg/hr
Oliguria on Children
<0.5mL/kg/hr
Oliguria on Adult
<400mL/kg/hr
Color orange urine is associated to what medication
bilirubin
acriflavine
pyridium,
nitrofurantoin
Pyridium can be mistaken as
Bilirubin
Method for Specific gravity
Direct method
Indirect method
Direct method for specific gravity
Urinometer/Hydrometer
Harmonic Oscillation Densitometry
Urinometer/Hydrometer sample volume
10-15mL
Refractometer/ Total Solid Meter sample volume
1-2 qtts
Seldom of clinical significance; not
part of routine urinalysis
Odor
Foul, Ammonia-like
bacterial decomposition, UTI
*Fruity, Sweet odor
Ketones (DM, starvation, vomiting)
Maple syrup odor
MSUD
Mousy odor
PKU
Rancid odor
Tyrosinemia
Sweaty Feet odor
Isovoleric acidemia
Cabbage odor
Methionine malabsorption
Rotting fish odor
Trimethylaminuria
Bleach
Contamination
Unusual or Pungent
Ingestion of onion, garlic,
asparagus
Lack of odor in urine from patients with Acute Kidney Injury suggests
Acute Tubular Necrosis
pH 9 suggests
Unpreserved urine
MOST INDICATIVE OF RENAL DISEASE
Protein
major serum protein
found in urine
Albumin
Produced by the renal tubules and forms matrix of all types of casts.
Tamm-Horsfall Protein
Clinical Proteinuria level of protein
> 30-300 mg/dL
Bence-Jones Protein precipitates at
40-60C
Bence-Jones Protein disappears at
100C
Undetected by reagent strips
Microalbuminuria
Methods for microalbuminuria
Micral test
Immunodip
Quantitative (24 hours urine)
Micral test sensitivity
0-10 mg/dL
Immunodip sensitivity
1.2-8 mg/dL
Reference method for albumin test
Heat and acetic acid test
A test with a principle where urine is coagulated by heat and precipitated by acetic acid (5-10%) and the
degree of turbidity produced is proportional to the amount of protein present
Heat and acetic acid test
SSA (+) and Rgt. Strip (+) =
presence of albumin
SSA (+) and Rgt. Strip (-) =
presence of proteins other than albumin
General test for glucose and other reducing sugars
Benedict’s test
Non-specific for glucose
Copper Reduction Method/Clinitest Tablet
Compositions: Crystal violet and Safranin O
Delineates structure and contrasting colors of the nucleus and cytoplasm
Sternheimer-Malbin
Enhances nuclear details
Toluidine
blue
Triglycerides and neutral fats: Orange-Red
LIPID STAINS: Oil Red O and Sudan III
Differentiates Gram (+) and Gram (-) bacteria
Gram Stain
Compositions: eosin y and methylene blue
Stains eosinophilic granules
Hansel stain
Stains structures containing iron
Prussian blue
Lyses RBCs and enhances WBC nuclei
2% acetic acid
Normal Acidic Crystals
Hippuric acid
Uric Acid
Calcium oxalate
Amorphous urates
Monosodium urates
Normal Alkaline Crystals
Amorphous phosphates
Calcium carbonate
Calcium phosphate
Ammonium biurate
Triple phosphate
Phenylalanine-Tyrosine Disorders
Melanuria
Tyrosyluria
Alkaptonuria
Phenylketonuria
