Renal Anatomy, Physiology, and Clinical Microscopy

These flashcards cover renal anatomy, physiology, function tests, urinalysis components, and common renal diseases based on clinical microscopy lecture notes.

Nephron

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

Cortical nephrons

Nephrons located in the cortex that make up approximately $85\%$ of the total; they are primarily responsible for waste removal and nutrient reabsorption.

Juxtamedullary nephrons

Nephrons with longer loops of Henle that extend deep into the medulla, primarily functioning in the concentration of urine.

Total Renal Blood Flow

The volume of blood delivered to the kidneys per minute, approximately $1200\,mL/min$.

Vasa Recta

Capillaries located adjacent to the ascending and descending Loop of Henle in juxtamedullary nephrons where major exchange of water and salt occurs.

Shield of Negativity

A glomerular filtration barrier component that repels molecules with negative charges, such as albumin, to prevent their passage into the ultrafiltrate.

Renal Threshold for Glucose

The plasma concentration at which active transport of glucose stops and it begins appearing in the urine, occurring at $160-180\,mg/dL$.

Renin-Angiotensin-Aldosterone System (RAAS)

A regulatory system that controls blood flow to and within the glomerulus, triggering the release of aldosterone and antidiuretic hormone (ADH).

Inulin Clearance

The gold standard method for measuring glomerular filtration because it is an exogenous substance that is neither reabsorbed nor secreted by the tubules.

Cystatin C

A small protein produced at a constant rate by nucleated cells, used as a GFR marker that is independent of muscle mass.

Beta2-Microglobulin

A marker used to distinguish between glomerular and tubular disorders; levels increase in blood during glomerular disorders and increase in urine during tubular disorders.

Osmolality

A tubular reabsorption test that measures only the number of particles in a solution.

Urochrome

The major pigment in normal urine that provides the yellow color; its production is directly proportional to the metabolic rate.

Oliguria

A decrease in urine output, defined as $<400\,mL/day$ in adults.

Anuria

The complete cessation of urine flow, defined as $<100\,mL$ in $24$ hours.

Polyuria

An increase in daily urine volume, defined as $>2.5\,L/day$ in adults.

Protein error of indicators

The principle of the reagent strip test for protein where indicators change color in the presence of albumin despite a constant pH.

Clinitest

A copper reduction test used as a non-specific screening tool for reducing sugars other than glucose, such as galactose.

Watson-Schwartz Test

A differentiation test used to distinguish between urobilinogen, porphobilinogen, and Ehrlich-reactive compounds using chloroform and butanol extraction.

Greiss reaction

The chemical principle utilized in Reagent Strip testing for Nitrite to screen for urinary tract infections.

Goodpasture syndrome

An autoimmune disorder characterized by the attachment of cytotoxic antibodies to glomerular and alveolar basement membranes, causing hemoptysis and hematuria.

Nephrotic Syndrome

A clinical condition involving massive loss of protein and lipids due to disruption of the shield of negativity and podocyte barrier.

Acute Tubular Necrosis (ATN)

Damage to the renal tubular epithelial cells often caused by ischemia or toxic substances, resulting in RTE cells and RTE casts in urine.

Fanconi Syndrome

A generalized defect in renal tubular reabsorption involving glucose, amino acids, phosphorus, and water, often seen in association with cystinosis.

Alport syndrome

A genetic disorder showing lamellated and thinning glomerular basement membrane, leading to hematuria and eventual renal failure.