Urinary System Reading Flashcards

Question

What would happen if filtration was too high or too low, what influences it?

Answer 1

* Too high * 250 ml/min * frequent urination * Increase in protein and glucose bc cant be reabsorbed * Too low * Dilute urine * Reabsorb too much * Influenced * diameter of blood vessels that feed system

Answer 2

* Transfer of fluid and solutes out of lumen of nephron through interstitial space and into peritubular capillaries

Answer 3

180 L/day of filtrate is made and only 1-2 L secreted 99% of filtrate i reabsorbed from renal tubules

Answer 4

Tubules have high reabsorptive capacity for essential substances and little to non for those of no value Only excess amounts of valuable substances are excreted

Answer 5

* Throughout renal tubules * Primarily in Proximal Convoluted Tubule

Answer 6

* Majority of sodium is reabsorbed Actively * Most in PCT (needed for glucose and AA reabsorption) * Loop of henle (role in kidneys ability to make dilute or concentrated urine) * Distal tubule (subject to hormonal control, aldosterone)

Answer 7

* Aldosterone regulate reabsorption of sodium in Distal and collecting duct * Renin-angiotensin aldosterone system

Answer 8

* 100% of glucose filteres is reabsorbed in Proximal tubule * Carrier-mediated transport of glucose displays the property of saturation * Concentration of transported molecules needed to saturate the carriers and achieve maximal transport rate is called Transport Maximum * Tm for glucose is 375 mg/min filtered * Normal glocose concentration in plasma is 100mg/100ml of plasma * Glucose levels above Tm will not be reabsorbed and will appear in urine--\> diabetes

Answer 9

* 1 mg/ml glucose in blood * 1 mg.ml X 125 ml/min=125 mg/min * Tm is 375 mg/min so no glu in urine * 3.5 mg/ml glucose in blood * TL: 3.5 X 125= 438 mg/min * Law of kidney= filtration-Reabsorption + secretion=Excretion * 438 mg/min - 375 mg/min= 63 mg/min in urine

Answer 10

* Active transport secretion of substances from * Peritubular capillarie--\> Kidney tubules--\> excretion in urine * Involves trans-epithelial transport (reverse of reabsorption)

Answer 11

* Hydrogen ions, potassium ions, penicillin, organic anions * H+ secretion important for acid-base balance and can be secreted in all tubular regions * Potassium is reabsorbed in PCT and actively secreted in DCT * K secretion is coupled to Na reabsorption and stimulated by Aldosterone

Answer 12

* Ratio of CO2 and HCO3 in extracellular fluid is increased * Net result is H ions are excreted and Na and HCO3 ions retained

Answer 13

* Ratio of HCO3 increases as pH rises * Net result is H ions are retained and bicarbonate ions are excreted * Kidneys help regulate the pH of fluids between 7.37-7.45

Answer 14

* Producing an osmotic gradient between tubular lumen and surrounding interstitial fluid * By amount of ADH secreted from posterior pituitary

Answer 15

* This Ascending limb actively transports neg Cl- OUT of tubular fluid into medullary interstium, Na follows bc of charge * Ascending limb impermeable to H2O * Fluid in ascending becomes more dilute (100 mosm/L) as it passes--\> cortex * Ions (Na, Cl) are actively transported into interstium from collecting duct, urea passively diffuses out of collecting duct into interstium * Peritubular capillaries contain 1-2% of renal blood flow, as result carries only a min amuont of medullary interstitial solutes are carried away from renal medulla * Net result- high osmolarity in medulla 1200-1400 osmos/L

Answer 16

* Distal tubules and collecting ducts become impermeable to water * No water reabsorbed, excess water eliminated * NaCl is still being pulled out and despite the high osmotic gradient, little H2O is pulled out into medulla * Producing Large vol of DiLUTE urine (100 mosm/L)

Answer 17

* ADH increases permeabi;ity of distal and collecting duct * More water is reabsorbed, less water lost in urine more water returned to blood * H2O is pulled out bc of high osmotic gradient in interstium * Producing small vol of CONCENTRATED urine (1200 mosm/L)

Answer 18

* Kidney plays imp role in BP regulation * Renin-Angiotensin-Aldosterone-System * Renin is made and secreted from Juxta App * Where distal CT contacts affernt arteriole near Bowmans capsule

Answer 19

* Dec in BP in affernt is sensed by * J cells * Inc in NaCl in DCT is sensed by * Macula densa * Both result in release of renin from J cells

Answer 20

* Tall densely packed cells * Contain Osmoreceptors which sense drop in blood osmotic pressure, change in [Na}

Answer 21

* Modified smooth muscle cells * Mechanoreceptors line wall of afferent arteriole * Sense pressure changes due to tension in arterial wall

Answer 22

* Glomerulus * Filtrate produced at renal corpuscle * Same comp as blood plasma minus plasma proteins * PCT * Active removal of ions and organic substrates * Produces osmotic water flow out of tubular fluid * Reduces vol of filtrate * Keeps solutions inside and outside tubule isotonic

Answer 23

* PCT and Descending Limb * Water moves into peritubular fluids leaving highly concentrated tubular fluid * Reduction in volume occurs by obligatory water reabsorption * Thick Ascending Limb * Tubular cells actively transport Na and Cl out of tubule * Urea accounts for higher proportion of total osmotic concentration

Answer 24

* DCT and collecting ducts * Final adjustments in composition of tubular fluid * Osmotic concentration is adjusted thru active transport (reabsorption or secretion based on ADH) * Urine production ends wehn fluid enters renal pelvis

Answer 25

* Stretch receptors in bladder send impulses to sacral spinal cord * Sensory neurons snd impulse to brain * Parasympathetic nerve impulses stimulates detrusor muscle and the internal urethral sphincter * Dertrusor muscle contracts and internal sphincter relaxes--\> have to pee really bad now! * To preevent use voluntary contraction of external urethral sphincter * To urinate, external urethral sphincter is relaxed, detrusor contracts

Urinary System Reading Flashcards

(49 cards)