Urinalysis and Body Fluids Review

A comprehensive set of vocabulary flashcards covering the safety, quality assessment, physiology, and physical, chemical, and microscopic examination of urine based on the provided textbook chapters.

Chain of infection

A continuous link between six components: an infectious agent, a reservoir, a portal of exit, a means of transmission, a portal of entry, and a susceptible host.

Fomite

An inanimate object, such as laboratory equipment or soiled clothing, that can serve as a reservoir for infectious agents.

Standard Precautions

A clinical guideline combining Universal Precautions and Body Substance Isolation that considers all body fluids and moist body substances to be potentially infectious.

RACE

An acronym for fire emergency actions: Rescue, Alarm, Contain, and Extinguish/Evacuate.

PASS

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

Quality Assessment (QA)

The overall process of guaranteeing quality patient care, encompassing preexamination, examination, and postexamination variables.

Preexamination variable

Factors that occur prior to specimen testing, such as patient identification, specimen collection, handling, and storage.

Examination variable

Processes that directly affect specimen testing, including reagent performance, instrument calibration, and technical competence.

Postexamination variable

Processes affecting the reporting and interpretation of results, such as transcription errors or failure to call critical values.

Oliguria

A decrease in urine output, defined as less than $400\,mL/day$ in adults or less than $0.5\,mL/kg/hr$ in children.

Anuria

The complete cessation of urine flow, often resulting from serious kidney damage or decreased blood flow to the kidneys.

Nocturia

An increase in the nocturnal excretion of urine.

Polyuria

An increase in daily urine volume, exceeding $2.5\,L/day$ in adults or $2.5$ to $3\,mL/kg/day$ in children.

Urea

A metabolic waste product produced in the liver from protein breakdown that accounts for nearly half of the total dissolved solids in urine.

Renal threshold

The plasma concentration at which active transport stops and a substance begins appearing in the urine; for glucose, this is $160$ to $180\,mg/dL$.

RAAS

Renin-angiotensin-aldosterone system; a hormonal system that regulates blood flow to the glomerulus in response to blood pressure and sodium changes.

Shield of negativity

A property of the glomerular filtration barrier that repels positively charged molecules, such as albumin, preventing them from entering the filtrate.

Creatinine clearance

A laboratory test used to determine the GFR ($\text{Glomerular Filtration Rate}$) by measuring the rate at which the kidneys remove creatinine from the blood.

Urochrome

The lipid-soluble pigment produced at a constant rate by endogenous metabolism that is responsible for the normal yellow color of urine.

Isosthenuric

Term used to describe urine with a specific gravity of $1.010$, which is equal to the specific gravity of the plasma filtrate.

Protein error of indicators

A chemical principle used in reagent strips where certain indicators change color in the presence of protein (primarily albumin) despite a constant pH.

Clue cell

A squamous epithelial cell covered with the coccobacillus Gardnerella vaginalis, appearing granular and irregular, indicative of vaginal infection.

Oval fat body

A renal tubular epithelial cell ($\text{RTE}$) that has absorbed lipids from the glomerular filtrate and appears highly refractile.

Maltese cross

A characteristic formation observed in cholesterol-containing droplets, such as oval fat bodies or fatty casts, when viewed under polarized light.

Uromodulin

A glycoprotein, formerly known as Tamm-Horsfall protein, that forms the matrix of all urinary casts and is produced in the distal convoluted tubule.

Glitter cells

Neutrophils that have swollen in hypotonic urine, showing brownian movement of granules which produces a sparkling appearance.

Triple phosphate crystal

An alkaline urine crystal frequently appearing as a colorless, six-sided prism resembling a "coffin lid."

Ammonium biurate crystal

A yellow-brown crystal found in alkaline urine that appears as spicule-covered spheres, often called "thorny apples."

Cystine crystal

An abnormal urine crystal appearing as colorless, hexagonal plates, indicative of an inherited metabolic disorder.

Sternheimer-Malbin stain

A supravital stain consisting of crystal violet and safranin O used to enhance the visualization of cells and casts in urine sediment.