flash cards

Chp24 Urinary system

Question Answer
Urinary system Pair of kidneys & urinary tract
Kidneys Filter blood to remove metabolic waste products
Urinary tract
Remove waste
Functions of kidneys
External coverings of kidney Renal fasciaAdipose capsuleRenal capsule
Renal fascia(dense irregular connective tissue) Anchors kidney to peritoneum
Adipose capsule(thickest layer)
Puts kidney in place; shield from shock
Renal capsule(thin layer of dense irregular connective tissue) Covers exterior of kidney; protection
Nephron Filter blood & modify filtered fluid
Nephron has 2 main division Renal corpuscleRenal tubule
Renal corpuscle(filter blood) Composed of 2 parts
Two parts of Renal corpuscle Glomerulus
Glomerular filtration rate Filtrate formed by kidneys in 1 minutes
Average value of Glomerular filtration 125ml/min
Tubular reabsorption Substance pass from filtrate in lumen of tubule across/between tubule cells into interstitial fluid, then across/btwn endothelial cella of peritubular capillaries to reenter blood
Tubular secretion Substance move in opposite direction
2 Routes for moving substances in renal tubule Paracellular & Transcellular
Paracellular Substance pass btwn adjacent tubule cells
Transcellular Larger substances (glucose& amino acids)move through tubule cells
Renal clearance Measurement of rate at which kidneys remove substance from blood
Micturition Urination/voiding; discharge of urine from urinary bladder
Micturition center (in pons)
Time/training makes micturition a voluntary process
Micturition reflex(mediated by PNS) urine fills bladder & stretches walla
Micrurition reflex Stretch receptors send signal to sacral region
Micturition reflex Parasympathetic efferent fibers stimulate detrusor muscle to contract & urethral sphincter to relax
Renal clearance and GFR can be estimated by measuring: Creatinine & Inulin
Creatinine Waste product of muscle cell metabolism
Creatinine Blood levels are elevated when kidneys are impaired; not accurate
Inulin Complex carbohydrate found in plants such as garlic & artichokes
Inulin Neither absorbed or secreted; most accurate
For substance to provide accurate measure of renal clearance and GFR Substance should be filtered & neither secreted or reabsorbed
Urine contains Water, sodium, potassium, chloride, hydrogen ion, phosphate & sulfates
Urine contains (Metabolic wastes)a??urea, creatinine, ammonia, uric acid
Urine may contain Bicarbonate, calcium, & magnesium
Urine color formed by Urochrome(yellow pigment),breakdown product of hemoglobin
Urine composition Translucent, ph ranges 4.5-8.0
Darker urine Is more concentrated; less water
Lighter urine Less concentrated; more water
85% of water reabsorption is Obligatory water reabsorption
15% of water can be adjusted Facultative water absorption
Obligatory Occurs in proximal tuble
Facultative Occurs in distal tuble & cortical collecting duct
Facultative Regulated by hormone stimulation
Facultative Determine final urine concentration
Medullary collecting system Last chance for regulation of fluid, electrolyte, acid base balance before filtrate becomes urine
Cells of medullary collecting system Impermeable to water im absence of ADH
Cells of medullary collecting system Permeable to urea; urea is reabsorbed
Cells of medullary collecting system Intercalated cells secrete H ions into filtrate against concentration gradient by 900 times

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