RENAL FUNCTION Flashcards
this weighs approximately 150g and measures 12.5cm x 6cm x2.5 cm (length, width, depth)
kidney
ureter measure ____ long
25 cm
when approximately 150 mL urine accumulates
bladder
urethra is __ cm long in women and __ cm long in men
4 cm; 24 cm
fluid biopsy of the kidney
urine
basic structural and functional unit of the kidney
nephron
how many nephrons are there PER kidney
1 to 1.5 million
what are the two type of nephrons
cortical and juxtamedullary
nephrons consists of
glomerulus and renal tubules
what is the order of urine formation
- Glomerulus
- Proximal Convoluted Tubule
- Loop of Henle
- Distal Convoluted Tubule
- Collecting Duct
- Calyx
- Renal Pelvis -> Ureter -> Bladder -> Urethra
the kidney receive ____ of the total cardiac output
25%
what blood is present in Renal Artery
Unfiltered blood
what blood is present in renal vein
filtered blood
what is the order of renal blood flow
- renal artery
- afferent arteriole
- glomerulus
- efferent arteriole
- peritubular capillaries
- vasa recta
- renal vein
total renal blood flow of 2 kidneys
1, 200 mL/min
total renal plasma flow of two kidneys
600-700 mL/min
the “working portion” of the kidney
glomerulus
glomerulus has a coil of approximately _____ (capillary tuft) located w/in the Bowman’s capsule
8 capillary lobes
these are attached to the glomerular basement membrane
podocytes (epithelial cells)
this resembles a sieve
glomerulus
how many daltons are able to pass through the glomerulus
< 70, 000 Daltons
approximately __ of the filtered plasma volume is actually excreted as urine
1%
what is found between the podocytes of Bowman’s space
Filtration Diaphragm
how many daltons albumin is
69k daltons
why is albumin not able to pass through the glomerulus
because of the shield of negativity
what is the charge of albumin
negative
when is albumin positive charge
at 4.9 pH
1st function to be affected in renal disease
tubular reabsorption
plasma concentration at which active transport stops
renal threshold
renal threshold for glucose
160- 180 mg/dL
these alter the urine concentration
PCT, LH, DCT, & CD
major site (65%) of reabsorption of plasma substance
PCT
renal concentration begins in the ______
descending and ascending LH
- Solute concentration is highest where
Loop of Henle (renal medulla)
true or false
the ascending loop of henle is highly permeable to water
false (highly impermeable)
Dam collects water, so does the _____
Descending loop of henle
Ascending loop of henle reabsorbs
a. Salt
b. Water
a. Salt (ASINding LH)
during the active transport, glucose, amino acids, and salts are located at the _____
PCT
location of sodium during active transport
PCT and DCT
location of water during passive transport
PCT, Descending LH, CD
Location of Urea during passive transport
PCT, ascending LH
location of sodium during passive transport
ascending LH
movement of molecules across a membrane by diffusion because of a physical gradient
passive transport
movement of a substance across cell membranes into the bloodstream by electrochemical energy
active transport
this regulates water reabsorption in the DCT and CD
Anti-diuretic hormone (ADH/Vasopressin)
ADH during increase of body hydration
decrease
Urine Volume during increase of body hydration
increase
ADH during decrease of body hydration
increase
Urine Volume during decrease of body hydration
decrease
ADH in Diabetes Insipidus
Decreased/Deficient (DI = Daming Ihi)
ADH in Syndrome of Inappropriate ADH secretion
ADH excess
regulates sodium reabsorption in the DCT
Aldosterone
Effects of Angiotensin II
- Release of Aldosterone and ADH
- Vasoconstriction
- Corrects renal blood flow
sodium and water reabsorption during the releasing of Aldosterone and ADH
INCREASE OR DECREASE
INCREASE
Blood Pressure during the increase of Sodium and water reabsorption
Increased
juxtaglomerular apparatus consists of the _____ in the afferent arteriole
JG cells
JG cells produce what
renin
this detects the decrease in Blood Pressure
Macula Densa
RAAS ____ the afferent arteriole and _____ the efferent arteriole
dilates; constricts
RAAS stimulates the sodium reabsorption in the
a. DCT
b. PCT
b. PCT
RAAS triggers the adrenal to release _____ to cause sodium reabsorption & potassium excretion in the DCT and CD
aldosterone
RAAS triggers the release of anti-diuretic hormone by the ______ to stimulate water reabsorption in the CD
Hypothalamus
2 major functions of tubular secretion
- regulation of the acid-base balance in the body through secretion of hydrogen ions (in the form of ammonium & dihydrogen phosphate
- elimination of waster products not filtered by the glomerulus
major site for removal of nonfiltered substances
Proximal Convoluted Tubule
_______ are secreted in exchange for sodium ions which are reabsorbed with bicarbonate into the plasma in the PCT
Hydrogen ions
failure to produce an acid urine due to inability to secrete hydrogens ions
Renal Tubular Acidosis (RTA)
blood pH during RTA
acidic (decreased)
Urine pH during RTA
alkaline (increased)
used to evaluate glomerular filtration
clearance test
clearance test measure the rate at which the kidneys are able to ________ from the blood
remove a filterable substance
clearance test is used for measuring what substances
- Urea
- Creatinine
- Inulin
- Beta2-microglobulin
- Radioisotopes
- Cystatin
what is the most common/routinely performed test creatinine
clearance test
specimen for creatinine clearance
24-hour urine
Reference range of creatinine clearance for male
107-139 mL/min
Reference range of creatinine clearance for female
87-107 mL/min
variables for cockgroft and gault
age, sex, & body weight in kg
variables for modification of diet in renal disease (MDRD) system formula
ethnicity, BUN, and Serum Albumin
used to evaluate tubular reabsorption
concentration tests
obsolete test that deprived the patient of fluid for up to 24 hrs
Fishberg test
Urine SG after 12 hr restricted fluid diet is about ____ or more
1.022
Urine SG after 24 hr restricted fluid diet is about ____ or more
1.026
obsolete test wherein the patient is deprived of fluid for up to 24 hrs
mesonthal test
it is influenced by the number & density of particles in a solution
Specific Gravity
influence by the number of particles in a solutiion
osmolality
it is more accurate and preferred than SG determination
Osmolality
most commonly used and reference method for tubular secretion & renal blood flow
p-aminohippuric acid (PAH) test
obsolete test for tubular secretion & renal blood flow because the results are hard to interpret
Phenolsulfonphtalein (PSP) test
hindu physicians that this attracted ants
honey urine
this is used by the Babylonians and Egyptians to detect diabetes
taste test
urine is composed of
95-97% water
3-5% solids
total solids are composed of
35 grams organic
25 grams inorganic
major constituent of organic total solids
urea
2nd major constituent of organic total solids
creatinine
other components of organic total solids
hippurate, uric acid, CHO, pigments, fatty acid, mucins, enzymes, hormones
major constituent of inorganic total solids
chloride
other inorganic total solids
chloride > sodium > potassium
sulfate. phosphate, ammonium, magnesium, calcium
principal salt of inorganic total solids
NaCl
urine spx that is used for routine screening tests and qualitative urinalysis
random /occasional/single urine
true or false
random urine sample is ideal for cytology studies
true BUT patient must have prior hydration & exercise 5 mins before collection
ideal specimen for routine screening/urinalysis and pregnancy testing (hCG)
First Morning Urine
true or false
first morning urine is not preferred for cytology studies/cytodiagnostic urine testing
First Morning Urine
it is the most concentrated and most acidic urine specimen that allows well preservation of cells and casts
First Morning Urine
why is first morning urine acidic
because we hypoventilate while sleeping (steady and slow breathing)
first morning urine is used for evaluation of
Orthostatic Proteinuria
it is the 2nd voided urine after a period of fasting
2nd morning urine/fasting
urine specimens for glucose determination
2-hour post prandial
Glucose tolerance
fractional specimen
glucose tolerance test is optional to be test with
blood samples
urine spx for diabetic screening and monitoring; preferred for glucose testing
2-hour post prandial
2nd morning urine is used for
glucose determination (but not recommended)
bladder urine for anaerobic bacterial culture and urine cytology wherein the abdominal wall is punctured, and urine is directly aspirated from the bladder
suprapubic aspiration
for routine screening and bacterial culture (OPD)
Midstream clean catch
urine spx used for bacterial culture (may urethral or ureteral)
catheterized
used in diagnosis of diabetes wherein series of blood and urine samples are collected at specific time intervals to compare concentration of a substance in urine with its concentration in the blood
fractional specimen
urines in three glass technique
- first portion of voided urine
- middle portion of voided urine
- urine after prostatic
massage
type of urine collection that uses soft, clear, plastic bag with adhesive
pediatric spx
3 glass technique result for prostatitis
- WBC bacteria
- Clear
- 10x greater WBC bacteria compared to 1st
3 glass technique result for healthy prostate
- WBC bacteria
- Clear
- Clear
control for bladder and kidney infection
2nd specimen
3 glass technique result for UTI
- WBC bacteria
- WBC bacteria
- WBC bacteria
the four glass method that consists of bacterial cultures of the initial voided urine (VB1), midstream urine (VB2), expressed prostatic secretions (EPS) and a post prostatic massage urine specimen (VB3)
Stamey-Meares Test for Prostatitis
process for 24 hour urine
at the start time, the patient will empty their bladder and the rest of the urine throughout the day will be collected (ex. 8AM to 8AM)
12 hr urine is used for
addis count (quantitation of formed elements)
4hr urine is used for
nitrite determination
why is 4hr urine used for nitrite determination
in the bladder, the bacteria will convert nitrate to nitrite (mas matagal mas maganda)
afternoon (2-4pm) urine is used for
Urobilinogen determination
process providing documentation of proper sample ID from the time of collection to the receipt of laboratory results
Chain of Custody (COC)
required urine volume for drug test
30-45 mL
container capacity for drug test specimen
60 mL (pinapapuno ng ibang lab kaya nagiging 60mL ‘yung required volume)
temperature of urine for drug test
32.5 - 37.7 ℃ (checked within 4 minutes)
added to the toilet water reservoir to prevent specimen adulteration
Blueing agent
following collection, urine specimens should be delivered to the laboratory promptly and tested within ____
2 hrs (ideally is within 30 mins)
increased in unpreserved urine
- pH
- Bacteria
- Odor
- Nitrite
Decreased in Unpreserved Urine
- Clarity
- Glucose
- Ketones
- Bilirubin (CB)
- Urobilinogen
- RBC/WBC/Casts
- Trichomonas
reason for increase in pH
Urea—–(Urease) —–> Ammonia; loss of CO2
reason for increase of nitrite
bacterial multiplication
darkened/modified urine is due to _____
oxidation or reduction of metabolites (increase of urobilin)
decrease of clarity is due to ____
bacterial multiplication; precipitation of amorphous material
decrease of ketones is due to ____
volatilization and bacterial metabolism
bacterial metabolism is due to ____
evaporation when the specimen is left uncapped