Analysis of Urine and Other Body Fluids Flashcards

Vocabulary practiced flashcards covering clinical microscopy topics including laboratory safety, renal function, urinalysis, and body fluid analysis (CSF, Semen, Synovial, Serous, Gastric, Fecal).

Chain of infection

A process of how microorganisms are transmitted from one person to another, requiring a continuous link between a source, mode of transmission, and susceptible host.

Biohazard label

An orange fluorescent label used for biological waste, with a symbol consisting of a plain trefoil (three equally overlapping circles).

Sodium hypochlorite ($NaOCl$)

Used in a $1:5$ or $1:10$ dilution for daily disinfection of laboratory sinks; the $1:10$ dilution is prepared with $1$ part $NaOCl$ to $9$ parts water and is effective for $1$ month.

Sharps hazards

Objects like needles, lancets, and broken glassware that must be disposed of in red, puncture-resistant containers.

Radioactive hazard disposal

Used radioactive material is stored in a locked, marked room until the background count is down to $10$ half-lives for radioiodine.

Acid handling rule

Always add acid to water ($A \& W$) to avoid splashing or explosions; never add water to acid.

NFPA Hazardous Materials Mnemonic

\u201cYou Were Born Right\u201d: Yellow, White, Blue, Red, starting from the rightmost quadrant.

Hazards Index

A scale from $0$ (no/minimal hazard) to $4$ (extreme/severe hazard), remembered by the mnemonic \u201cNo SMS Ex\u2019s\u201d.

R.A.C.E.

An acronym for fire discovery procedures: Rescue, Alarm, Contain, Extinguish/Evacuate.

P.A.S.S.

An acronym for fire extinguisher operation: Pull the pin, Aim at the base of the fire, Squeeze handles, and Sweep nozzle side to side.

Class B Fire

Fires involving flammable liquids such as grease, gasoline, paints, and oil; requires dry chemical, $CO_2$, or halon foam extinguishers.

Nephron

The basic structural and functional unit of the kidney, with approximately $1$-$1.5$ million found per kidney.

Glomerular Filtration Rate ($GFR$)

The volume of plasma filtered across the glomerular barrier per unit time; the total renal blood flow is approximately $1200\,mL/min$.

Renal threshold for glucose

The plasma concentration at which active transport of glucose stops, typically $160$-$180\,mg/dL$.

Anti-diuretic hormone ($ADH$)

Also called vasopressin; it regulates water reabsorption in the $DCT$ and $CD$; deficiency leads to Diabetes Insipidus.

Renin-Angiotensin-Aldosterone System ($RAAS$)

A system where renin (produced by $JG$ cells) triggers a cascade leading to vasoconstriction and sodium/water reabsorption via aldosterone and $ADH$.

Inulin

A polymer of fructose ($MW: 5200\,Da$) that is the gold standard/reference method for clearance tests but is not routinely performed.

Creatinine Clearance ($C_{cr}$)

The most common clearance test used to evaluate glomerular filtration, calculated using the formula $C_{cr} = \frac{UV}{P} \times \frac{1.73m^2}{A}$.

Uroscopy

The historical practice of diagnosing disease by looking at urine; the first illustrated medical book on this was Johannes de Ketham's Fasciculus Medicinae ($1491$).

Isosthenuria

Urine with a fixed specific gravity of $1.010$, indicating that the kidneys can no longer concentrate or dilute the urine.

Urochrome

The major pigment in urine that provides its yellow color; production is proportional to metabolic rate and increases in fever or starvation.

Portwine urine

A dark red or purple urine color associated specifically with porphyrin disorders (porphyrias).

Specific Gravity ($SG$) Reagent Strip Principle

$pKa$ change of polyelectrolyte; the strip is sensitive to the number of ions in urine, changing color from blue ($1.000$) to yellow ($1.030$).

Bence-Jones Protein ($BJP$)

Immunoglobulin light chains found in Multiple Myeloma that precipitate at $40$-$60^\circ C$ and dissolve at $100^\circ C$.

Glucose Reagent Strip Principle

Double sequential enzyme reaction involving glucose oxidase and peroxidase.

Pass-through phenomenon

Occurs in the Clinitest when glucose levels exceed $2\,g/dL$, causing the reaction color to cycle from orange/red back to blue or green-brown.

Acetone

A ketone body ($2\%$ of total ketones) only detected by the sodium nitroprusside reagent strip if glycine is present.

Myoglobinuria

The presence of myoglobin in urine resulting from muscle trauma (rhabdomyolysis); produces clear red or brown urine and high serum $CK$ and aldolase.

Ictotest

A tablet confirmatory test for bilirubin that is more sensitive than the reagent strip; yields a blue to purple color result.

Watson-Schwartz Test

A test used to differentiate urobilinogen ($UBG$), porphobilinogen ($PBG$), and other Ehrlich-reactive compounds via chloroform and butanol extraction.

Greiss Reaction

The chemical principle specific for the detection of nitrite on reagent strips to screen for bacteriuria.

Sternheimer-Malbin ($SM$)

The most common sediment stain (crystal violet and safranin $O$) used to delineate the nucleus and cytoplasm of $WBCs$, epithelial cells, and casts.

Glitter cells

Neutrophils in hypotonic urine that swell and show Brownian movement of granules, creating a sparkling appearance; they stain pale blue with $SM$ stain.

Clue cells

Squamous epithelial cells covered with Gardnerella vaginalis, associated with bacterial vaginosis.

Oval fat body

A lipid-containing renal tubular epithelial ($RTE$) cell that exhibits a \u201cMaltese cross\u201d formation under a polarizing microscope due to cholesterol content.

Tamm-Horsfall protein

Also called uromodulin; the major constituent of mucus threads and the matrix for all casts, produced by $RTE$ cells in the $DCT$ and collecting duct.

Waxy cast

The final degenerative form of all types of casts, appearing brittle and highly refractile with jagged ends and a ground glass appearance.

Amorphous urates

Normal acidic crystals that appear as yellow-brown granules microscopically and as pink \u201cbrick dust\u201d sediment macroscopically due to uroerythrin.

Triple phosphate

Colorless, prism-shaped or \u201ccoffin-lid\u201d crystals found in alkaline urine, often associated with urea-splitting bacteria.

Phenylketonuria ($PKU$)

An aminoaciduria caused by a lack of phenylalanine hydroxylase, resulting in urine with a \u201cmousy\u201d odor and potential severe mental retardation.

Alkaptonuria

A metabolic disorder caused by a lack of homogentisic acid oxidase; urine darkens to brown or black upon air exposure or alkalinization.

Maple Syrup Urine Disease ($MSUD$)

A deficiency in branched-chain $\alpha$-keto acid dehydrogenase leading to an accumulation of Leucine, Isoleucine, and Valine; characterized by a caramelized sugar odor.

Lesch-Nyhan disease

A purine disorder due to lack of the enzyme $HGPRT$, resulting in excess uric acid and \u201corange sand\u201d in infant diapers.

Nephrotic Syndrome

A condition characterized by massive loss of proteins ($>3.5\,g/day$) and lipids, resulting in oval fat bodies, fatty casts, and decreased serum albumin.

Human Chorionic Gonadotropin ($hCG$)

A hormone produced by syncytiotrophoblast cells of the placenta; clinical tests utilize the beta subunit for specificity.

Polyhydramnios

An excess of amniotic fluid ($>1200\,mL$) often caused by decreased fetal swallowing of urine or neural tube defects.

Lecithin/Sphingomyelin ($L/S$) ratio

The reference method for assessing fetal lung maturity via thin layer chromatography; a ratio of $>2.0$ indicates mature lungs.

Sialic acid

The most important single component of sputum viscosity.

Charcot-Leyden crystals

Colorless, hexagonal, double pyramid crystals found in the sputum of patients with bronchial asthma, arising from the disintegration of eosinophils.

Sweat test

The use of pilocarpine iontophoresis to diagnose Cystic Fibrosis (Mucoviscidosis) by measuring sodium and chloride levels ($>70\,mEq/L$ is diagnostic).

Xanthochromic

A pink, yellow, or orange appearance of $CSF$ supernatant caused by hemoglobin degradation products, indicating intracranial hemorrhage.

Oligoclonal bands

Electrophoretic bands in the gamma region of $CSF$ that, when absent in serum, are indicative of Multiple Sclerosis.

Limulus Amoebocyte Lysate ($LAL$) test

A test using the blood of the horseshoe crab to detect Gram-negative endotoxin in body fluids.

Azoospermia

The complete absence of spermatozoa in the ejaculate.

Fructose

The primary nutrient for sperm motility produced by the seminal vesicles; screened using the resorcinol (Seliwanoff\u2019s) test.

Synovial fluid

Joint fluid whose viscosity is provided by the polymerization of hyaluronic acid; often described as resembling egg white.

Monosodium urate ($MSU$)

Needle-shaped crystals with negative birefringence found in the synovial fluid of patients with gout.

Transudate

A clear serous fluid accumulation caused by systemic disruptions in hydrostatic/oncotic pressure (e.g., $CHF$), having a fluid:serum protein ratio of $<0.5$.

Exudate

A cloudy serous fluid accumulation caused by direct membrane damage (e.g., infection/malignancy), having a fluid:serum protein ratio of $>0.5$.

Zollinger-Ellison Syndrome ($ZES$)

A condition caused by a gastrin-secreting pancreatic tumor, leading to hyperchlorhydria and elevated $BAO/MAO$ ratios.

Steatorrhea

Increased fat in the stool ($>6\,g/day$), which may appear bulky, frothy, or butter-like.

Creatorrhea

The abnormal excretion of undigested muscle fibers in the feces, detected by emulsifying stool with $10\%$ eosin.

Apt Test

Also called the Apt-Downey test; it uses $1\%\,NaOH$ to differentiate fetal blood (remains pink) from maternal blood (turns yellow-brown) in infant stool or vomitus.