Urine Composition and Kidney Function

Flashcards covering urine composition, kidney stones, renal clearance, and hemodialysis.

What pigment causes urine to be yellow to colorless?

Urochrome

What can cause urine to be pink?

Blood or foods with magenta pigments

What can cause urine to be orange?

Dehydration or bile in blood

What can cause urine to be green?

Food coloring, dyes, or Pseudomonas aeruginosa infection

What can cause urine to be brown?

Extreme dehydration, chloroquine, other drugs

What can cause urine to be black?

Alkaptonuria

What is Pyuria?

Pus in urine

What can pyuria indicate?

Kidney infections

What is Hematuria?

Blood in urine

What can hematuria indicate?

UTI, trauma, kidney stones

What causes odor in standing urine?

Bacteria

What process causes the odor in standing urine?

Urea -> ammonia

What condition is associated with sweet, acetone-smelling urine?

Diabetes Mellitus

Why does diabetes mellitus cause sweet-smelling urine?

Increased fatty acid metabolism -> more ketones

What can cause urine to have a rotten smell?

UTI

What is the normal osmolarity range of urine?

50-1200 mOsm/L

What is the normal pH of urine?

Approximately 6.0 (4.8-8.2)

What are normal solutes found in urine?

Urea, NaCl, KCl, bicarbonate, titratable acids, calcium

What are abnormal solutes found in urine?

Glucose, free hemoglobin, albumin, ketones, bile pigments, and protein

What are kidney stones made of?

Minerals and salts

Under what condition do kidney stones form?

Urine is highly concentrated

What are the most common substances that crystallize to form kidney stones?

Calcium, oxalate, and uric acid

What condition is associated with calcium stones?

Hypercalciuria

Where does oxalate come from that is used to produce calcium oxalate stones?

Oxalate from diet and liver

What causes uric acid stones?

Not enough fluid consumption or high protein diet leading to acidic urine.

What causes cystine stones?

Hereditary condition where the kidney excretes too many amino acids

What is renal clearance?

Volume of plasma from which a waste product is removed in one minute

In the renal clearance formula C = UV/P, what do U, V, and P stand for?

U = [waste] in urine, V = rate of urine output, P = [waste] in plasma

What substances can be used to measure Glomerular Filtration Rate (GFR)?

Creatinine and Inulin

What is inulin?

Polysaccharide in some plants

What level of kidney function loss constitutes kidney failure?

Loss of over 75-90% kidney function

What are the major steps in hemodialysis?

Blood from radial artery -> dialysis chamber, Blood flows through tube with semipermeable membrane, Solutes diffuse out of blood into dialysis fluid, Blood returned into radial vein

What components can be added to dialysis fluid during hemodialysis?

Glucose, electrolytes, drugs, EPO, Heparin