Tubular Reabsorption and Secretion

Urinary system work sheet Name: ______Viviana Nute_________ Interactive Physiology Activity Watch the associated videos on tubular secretion and reabsorption (3-13). For each activity, answer the questions on this work sheet. Activity: Trace the Filtrate Flow Select the letter that represents the structure for each step of filtrate flow. 2) ____PCT_____ (majority of reabsorption occurs here) 1) ______glomerulus____ (site of filtrate entry) 4) __DCT and collecting duct______ (reabsorption of variable amounts of water and secretion of specific ions) 3) _____nephron loop___ (additional reabsorption of ions and water) A) B) C) D) DCT and collecting duct Peritubular capillaries Glomerular capsule PCT 5) For each of the substances below label whether the proximal convoluted tube will secrete or reabsorb this substance. Ions - _____reabsorption_______________ Lipid-soluble solutes - __secretion__________________ Glucose - _________reabsorption_____________________ Water - __________reabsorption______________________ Certain metabolic wastes - _______secretion_______________________ 6) Which of the substances below will be reabsorbed by the nephron loop? Circle all that apply A) B) C) D) E) Toxins Water Glucose Ions Wastes 7) For each of the substances below indicate whether they are secreted, reabsorbed or both in the DCT and collecting duct. Ions - _____reabsorption_______________ Toxins - ____secretion________________ Wastes - ____secretion__________________________ Water - _____reabsorption___________________________ Activity: Driving Force of sodium 8) When the number of Na+-K+ ATPases in the basolateral membrane increases, sodium reabsorption will: A) Increase B) Decrease C) Stay the same Activity: Dietary Choices in Glucose Levels 9) Under normal blood glucose levels, ____________________ the glucose molecules will be reabsorbed from the filtrate A) B) C) D) Half of None of All of Some of 10) What factor limits the amount of glucose that can be reabsorbed by the proximal convoluted tubule (PCT)? The number of _________________________________. ( ) A) B) C) D) Na+-glucose symporters in the apical membrane of the PCT Na+-K+ ATPases in the basolateral membrane of the PCT facilitated diffusion carriers for Na+ in the apical membrane of the PCT facilitated diffusion carriers for K+ in the basolateral membrane of the PCT 11) The maximum rate at which glucose can be reabsorbed from the tubule fluid is called the: A) B) C) D) Transport maximum Renal threshold Renal clearance Renal autoregulation Activity: Phys Quiz 12) During osmosis, water moves toward ___highest solute concentration_____. 13) Which transport pathway involves the transport of a solute across both the apical and basolateral membranes of a tubular epithelial cell? A) B) C) D) active transport transcellular transport acellular transport paracellular transport 14) Sodium ions can move down their concentration gradient across the apical membrane of PCT by which process? A) B) C) D) facilitated diffusion simple diffusion osmosis primary active transport 15) Which hormone causes an increase in urine volume and urine sodium content? ANP- atrial natriuretic peptide 16) Which two hormones promote facultative water reabsorption? Aldosterone and antidiuretic hormone (ADH) 17) A decrease in blood volume and an increase in extracellular fluid osmolarity leads to the formation of what? A) B) C) D) a urine high in protein a urine of average volume and concentration a large volume of concentrated urine a small volume of concentrated urine 18) Molly is producing a copious, dilute urine on an ongoing basis and is severely dehydrated. This could be due to which condition? A) B) C) D) Overproduction of aldosterone Vasodilation of the afferent arterioles Absence of ADH Excessive ADH secretion Activity: Potassium Sparing Diuretic 19) Where are aldosterone receptors found? Select all that apply. A) PCT B) DCT C) Nephron loop D) Collecting duct 20) What two transport proteins are regulated by aldosterone? A) B) C) D) Na+-K+ ATPases and K+ channels Na+-glucose symport and ADH-regulated aquaporin Na+-K+ ATPases and Na+ channels Na+ channels and ADH-regulated aquaporin 21) For all of the following transport proteins, indicate whether they are found on the apical membrane, basolateral membrane or both. ( The simulation may not be correct or complete with their answers.) Na+-K+ ATPases: ___both_____ Na+ channels: ___apical membrane_________ K+ channels: _____basolateral membrane_______ Na+-glucose symport: ____apical membrane______ ADH-regulated aquaporin: _____both_____ 22) What is the function of aldosterone? A) B) C) D) stimulates the excretion of sodium inhibits the reabsorption of water stimulates the reabsorption of sodium stimulates the reabsorption of potassium 23) What would be the effect of inhibiting aldosterone? A) B) C) D) Sodium would enter the urine Potassium would be reabsorbed Water would follow sodium into the urine (assume ADH is present) All of these are effects of inhibiting aldosterone 24) How would inhibiting aldosterone affect blood volume and urine volume (assume ADH is present)? A) B) C) D) Urine volume would decrease and blood volume would increase Urine volume would increase and blood volume would decrease Both urine volume and blood volume would increase Both urine volume and blood volume would decrease 25) Why would inhibiting aldosterone help to control high blood pressure? A) Sodium and water remain in the filtrate, increasing urine volume and decreasing blood volume. B) Water follows sodium from the filtrate into the blood, increasing blood volume and decreasing urine volume. C) Water follows sodium into the urine, but does not result in a significant change in blood volume. D) This medication lowers her stress level so her blood pressure goes down.