MTAP 2 Flashcards
kidney weighs
150g (male)
135 (female)
urethra’s distance
20 cm
3-4 cm
basic functional/ structural unit of the kidney
nephrons
how many nephrons are there
1 - 1.5 millions in one kidney
- seen in cortex alone
- for Tubular Reabsorption and Secretion (removal of wastes)
cortical nephrons
cortical nephrons percentage
85%
cortical nephrons is for
tubular reabsorption and secretion
juxtamedullary nephrons percentage
15%
loop of Henle extends into medulla for the concentration of urine
juxtamedullary nephrons
percentage of cardiac output received by the kidneys
25%
Total Renal Blood Flow
1,200 mL/min
Total Renal Plasma Flow
600-700 mL/min
carries the blood to the glomerulus
Afferent Arterioles
carries blood from the glomerulus
Efferent Arterioles
surround the PCT and DCT
Peritubular Capillaries
- located adjacent to the loops of Henle in
juxtamedullary nephrons - major exchanges of water and salts take place
Vasa Recta
coil of 8 capillary lobes collectively referred as the capillary tuft
Glomerulus
how much is filtered through the glomeruli
120 mL/min, or one-fifth of the renal
plasma
created by the varying sizes of the
arteriole
Hydrostatic Pressure
maintained by the exchange of water
and salts in vasa recta
Osmotic Gradient
the force exerted by albumin and other
proteins in the blood vessels
Oncotic Pressure
repels molecules with NEGATIVE charge due to endothelial cells’ negative charge
Shield of Negativity
which is a smaller size afferent or efferent arteriole
Efferent Arteriole
what is the Glomerular Ultrafiltrate specific gravity
S.G: 1.010
what is the Glomerular Ultrafiltrate pH
pH 7.4
- regulates the flow of blood to and within the glomerulus.
- responds to changes in blood pressure and plasma sodium content.
Renin-Angiotensin-Aldosterone System (RAAS)
It secretes RENIN
Juxtaglomerular Cells
Juxtaglomerular Cells stimulant
Low Blood Pressure
Juxtaglomerular Cells found in
Afferent arteriole
Macula Densa Cells found in
Distal Convoluted Tubule
Macula Densa Cells stimulant
Low Blood Volume
First function to be affected in renal disease
Tubular Reabsorption
Active Transport by PCT
Glucose
Amino acid
Salts
Active Transport by Ascending Loop of Henle
Chloride
Active Transport by DCT
Sodium
Passive Transport by PCT
Water
Urea
Passive Transport by Ascending Loop of Henle
Sodium
Urea
Glucose renal threshold
160-180 mg/dL
Threshold Substances:
Sodium chloride
Amino acids
Potassium
Ascorbic acid
Creatine
when urine glucose is positive while
blood glucose is normal.
Tubular Damage
Tubular Concentration begins in the
Descending LH to Ascending LH
The final concentration is in the
DCT to collecting duct
selective reabsorption of water in an ascending loop of Henle and serves to maintain the osmotic gradient of
the medulla.
Countercurrent Mechanism
Involves the passage of substances from the blood in the peritubular capillaries to the tubular filtrate.
TUBULAR SECRETION
major site for removal of nonfiltered substances (foreign substances such as medications) due to their stronger affinity to the tubular cells.
Proximal CT
Clearance Tests presents
Creatinine
B2-Microglobulin
Cystatin C,
Radioisotopes
- require the collection of a 24-hour urine sample along with
a blood sample - endogenous procedure
- not reliable for patients suffering from muscle-wasting disease, heavy exercise, and for athletes taking creatine
Creatinine Clearance Test
Creatinine Clearance Test: Greatest Source of Error
use of improperly timed
urine specimen
Creatinine Clearance Test normal values for men
107-139 mL/min
Creatinine Clearance Test normal values for women
87-107 mL/min
the earliest GFR test (40% is reabsorbed)
Urea Clearance Test
- Inulin: polymer of fructose
- the original reference method for clearance tests
- gold standard for measuring GFR
- exogenous procedure (disadvantage)
Inulin Clearance
a small protein produced at a constant rate by all nucleated cells
- Advantage: It is independent of muscle mass
Cystatin C
Cystatin C molecular weight
MW: 13,359
- dissociates from human leukocyte antigens (HLA) at a constant rate and is rapidly removed from the plasma by glomerular filtration
- not reliable in patients who have a history of immunologic disorders or malignancy
Beta2- microglobulin
Beta2- microglobulin molecular weight
MW: 11,800
can be valuable to measure the viability of a transplanted kidney
Radionucleotides
patients were deprived of fluids for 24 hours before measuring specific gravity
Fishberg Test
compared the volume and specific gravity of day and night urine samples to evaluate
concentrating ability
Mosenthal test
Influenced by the number and density of particles in a solution
is most useful as a screening procedure
Specific Gravity
has the disadvantage of requiring
large volume of specimen (10-15 mL)
Urinometer
determines the concentration of dissolved
particles in a specimen by measuring
refractive index; requires correction
Refractometer
measures only the number of particles in a
solution
Osmolality
Serum Osmolality NV
275-300 mOsm
Urine Osmolality NV
50 to 1400 mOsm
determined by first calculating the osmolar
clearance using the standard clearance formula and then subtracting the osmolar clearance value from the urine volume in mL/min.
Free Water Clearance
most commonly associated with tubular secretion and renal blood flow
P-aminohippuric acid (PAH) test
obsolete, historical, results hard to interpret
Phenolsulfonphthalein (PSP) Test
Centrifuged is calibrated every
3 months
Centrifuged is disinfected every
weekly
Average Daily Urine Output
1,200 mL
Normal Daily Urine Output
1200-1500mL/ 600-2000mL
Polyuria in children
> 2.5-3.0 mL/kg/day
Polyuria in adult
> 2.5 L/kg/day
Oliguria in Infant
<1 mL/kg/hr
Oliguria in Children
<0.5 mL/kg/day
Oliguria in Adult
<400 mL/day
for detection of prostatic infection
Three Glass technique
Drug Specimen volume
30-45 mL
Drug Specimen temperature
32.5 - 37.7C
12-hour urine for
addis count
- will precipitate protein (large concentration)
- give a false-positive test for reducing substances
formalin
- floats on the surface of the urine
- flammable
Toluene
- Interferes with the acid precipitation test for protein
Thymol
- Urine culture
- Bacteriostatic to contaminants
- interferes with the pH reading
Boric acid
Routine UA Volume
10-15 mL (Ave: 12 mL)
not indicative of actual renal disease not indicative of actual renal disease
Prerenal Proteinuria
Bence Jones Protein: coagulates at
40 - 60C
Bence Jones Protein: dissolves at
100C
associated with true renal disease.
Renal Proteinuria
a cold precipitation test that reacts equally with all forms of protein
Sulfosalicylic Acid Precipitation Test
Total volume of CSF in adult
140 - 170 mL
Total volume of CSF in neonates
10 - 60 mL
Xanthochromia if pink
very slight amount of oxyhemoglobin
Xanthochromia if orange
heavy hemolysis
Xanthochromia if yellow
conversion of oxyhemoglobin to unconjugated bilirubin
Lymphocytes> Monocytes
Adults
Lymphocytes< Monocytes
Neonates
associated with cytogenetic analysis
product of fetal metabolism
AMNIOTIC FLUID
AMNIOTIC FLUID method of collection
Amniocentesis
