fall week 1 urinalysis

kidneys

removes, reabsorbs water electrolytes and nutrients, syn hormones (Aldosterone, ADH, renin, EPO, vit D), maintain balance and bp

vit D

activated by kidneys, needed for calcium reg

renal cortex

outer layer of kidney, houses blood filtering parts of nephron (glomeruli and convoluted tubules)

renal medulla

inner part of the kidney, cone shaped renal pyramids, contains tubules that control salt and water levels of urine

renal pelvis

large funnel shaped space at center of kidney, collecting basin for urine of smaller cup like calyces and channels it into ureter to exit the kidney

renal interstitium

fluid-filled space and tissue matrix between the tubular and vascular structures of the medulla, helps maintain osmotic environment

upper UTI

renal pelvis, tubules, interstitium

pyelonephritis

upper UTI of nephron and interstitium

nephron

form urine, 1-1.5 mill per kidney, cortical (85%, in renal cortex, removal and reabsorb), juxtamedullary (longer loops of Henle deep into medulla, concentrates urine)

urine filtration through the nephron

glomerulus, Bowmans capsule, proximal covoluted tubule, loop of henle, distal convoluted tubule, collecting duct, renal calyces, ureter, bladder, urethra

blood path near the nephron

renal artery, afferent arteriole, glomerulus, efferent arterole, peritubular capillaries, vasa recta, renal vein

efferent arterole

smaller creating hydrostatic pressure differential for glomerular filtration

peritubular capillaries

surround PCT and DCT immediately reabsorption of essential subs and final adjustment of urinary composition

vasa recta

run alongside the loops of henle in juztamedullary nephrons, exchange of water and salts between blood and medullary interstitium maintaining osmotic gradient medulla needs for urine concentration

lower UTI

urethra and bladder

cystitis

bladder infec

urine formation

glomerular filtration, tubular reabsorption, tubular secretion

purpose of renal blood flow for urine formation

supply plasma for kidneys to filter, create bp for filtration, deliver/remove subs in tubular reabsorption and secretion

glomerular filtration

20% if plasma entering becomes filtrate, kidneys filter 180 liters/day through the glomeruli, capillary wall (fenestrated endothelium), basement membrane, visceral epithelium of Bowmans capsule

capillary wall (fenestrated endothelium)

contain pores (fenestrations) that increase permeability but block the passage of large molecules & blood cells

visceral epithelium of Bowmans capsule

foot processes of cells form thin filtration slits that enhance restriction

glomerulus

coil of 8 capillary lobes inside Bowman capsule, nonselective filter for plasma under 70,000, size based filtration and shield of negativity (repel albumin)

hydrostatic pressure

drives filtration across glomerular barrier by opposing fluid pressure (Bowman capsule) & oncotic pressure of unfiltered plasma proteins (glomerular capillaries)

Juxtaglomerular apparatus

keeps glomerular bp constant by adjusting size of afferent & efferent, low bp AA dilates and EA constricts (prevents drop in renal blood and toxic waste buildup), high bp AA constricts (preventing over filtration or damage)

macula densa

cells in the juxtaglomerular apparatus that act as sensors measuring amount of salt passing through tubule if low triggers RAAS

specific gravity of filtrate

1.010, 120 mL of plasma per min

tubular reabsorption

80% of fluid and electrolytes filtered by the glomerulus are reabsorbed by tubules into the blood, passive and active transport

active transport substances

sub reabsorbed with carrier protein and energy, glucose + AAs + salts PCT, chloride A-Henle, sodium PCT DCT

passive transport substances

uses concentration or electrical gradient, water PCT D-Henle collecting duct, urea PCT A-Henle, sodium A-Henle

abnormally high fluid and electrolytes in plasma

more than renal threshold= spill into urine, affects active tubular maximum, threshold for glucose 160-180 high = glucosuria

countercurrent mech

water removed in D-Henle by osmosis, salt reabsorbed actively in A-Henle maintaining medullary/osmotic gradient (high in medulla with loops)

selective A-Henle

impermeable to water only reabsorbs Na and Cl, prevents medullary interstitium dilution

Aldosterone

regs Na reabsorption in DCT, controlled by bodys Na concentration, produced by adrenal cortex

ADH

reg H2O reabsorption in late DCT and collecting duct, controlled by bodys H2O concentration, produced by hypothalamus, released by pituitary gland, determines wall permeability

tubular secretion

reverse reabsorption, moves subs from blood in peritubular capillaries into tubular filtrate, eliminates nonfiltered by glomerulus products (drugs bound to plasma proteins), reg acid-base balance by secreting H+

acid- base balance

secretion of excess acid H+ (phosphate buff and ammonium) and reabsorption of 100% filtered HCO3-, pH 7.4

phosphate buffering

secreted H+ ion combines with a filtered phosphate uin and is excreted

ammonium formation

PCT- breakdown of glutamine, reacts with H+ forming ammonium ion to be excreted

DCT and collecting duct- produces ammonium ions if more H+ elimination is needed

loop of Henle

coutercurrent mechanism preserving osmotic gradient of medulla, moves H2O and NaCl

collecting duct

hydrated, decrease ADH= lots of urine

RAAS purpose

activated in response to renal blood flow, drops blood pressure in kidney causing renin secretion, aldosterone tells distal tubule to reabsorb NaCl and H2O, increase ADH

renin secreted by jux cells

reacts with angiotensinogen (bloodborne substrate produced by liver) to form angiotensin I (inert hormone) which passes through the lungs and is converted to II (active)

angiotensin II

corrects renal blood flow & bp by vasoconstriction, Na reabsorp in PCT, aldosterone Na reabsorption and K excretion in DCT and collecting duct, ADH H2O reabsorption in collecting duct

urine composition

95% water, 5% solute, influenced by diet, nutrition/hydration, metabolic rate

urea

primary organic component, product of protein and AA metabolism

creatinine

always in urine at predictable rate, indicate urine concentration, easy tests

uric acid

organic, product of nucleic acid in food and cells breakdown

chloride

primary inorganic component, found with salt and other inorg subs

potassium

inorg, with chloride and other salts

phosphate

inorgan, with sodium to buffer the blood

ammonium

inorg, regulates blood and tissue fluid acidity

calcium

inor, with chloride sulfate and phosphate

urine vol

norm 600-2000 mL/day, 1200-1500, oliguria (less than 400) anuria (none from kidney damage or low renal blood flow) polyuria (more than 2.5 L, diabetes, diuretics, caffine, alc, suppress ADH)

first morning test

most concentrated, routine screening, preg, orthostatic protein

24 hr or times urine test

quantitative chem

catherterized sample

bacterial culture, sterile from urethra into bladder

midstream clean catch sample

routine and bac culture

suprapubic aspiration sample

bladder urine through abdominal wall for bac culture, cytology, infants and kids

sample container

routine- 50-100 mL, leak proof, clear plastic, sterile or nonsterile

large vol- 2000-3000 mL, opaque

changes to sample over time

increase in turbidity, bacteria, precipitation, nitrites

decrease- glucose, cells (rbc wbc trich), bilirubin, ketones (volatile)

macroscopic

physical and chemical

urinary system

2 kidneys, 2 ureters, bladder, urethra

renal artery

where blood enters the kidneys (25% from heart) and leaves through the renal vein, total blood 1200mL/min, plasma 600-700

urine flow

forms in kidneys, drains into renal pelvis, funneled into ureter, travels to bladder for temp storage, eliminated through urethra

refrigerating urine

warm to rt before testing, slows bac growth, can cause amorphous urate and phosphate crystals to precipitate out complicating microscopic exam

chemical urine preservative

boric acid, formalin, bactericidal, inhibit urease activity, preserve formed elements, not interfere with chem testing