Font Paragraph Styles Which of the following is TRUE about the reabsorption proc
ID: 3523064 • Letter: F
Question
Font Paragraph Styles Which of the following is TRUE about the reabsorption process in the proximal convoluted tubule? (a) Na +ions are actively transported out of the tubule and into the peritubular b) Negatively charged ions (e g. chloride) are transported out of the tubule in (c) Water is reabsorbed into the peritubular capillaries because of the (d) All of the above capillaries response to the movement of sodium increased osmotic pressure 5. Which of the following statements is FALSE about the glomerulus and the processes that occur there? (a) Capsular hydrostatic pressure refers to the pressure of fluid pressing on the capsule and opposes filtration (b) Net filtration pressure in the glomerulus is the difference between forces favoring filtration and forces opposing filtration (c) Blood from the afferent arteriole is filtered by size when it enters the glomerulus because of the many fenestrae (d) Vasoconstriction of the efferent arteriole lowers glomerular filtration rate 6 The descending limb of the nephron loop is impermeable to water while the ascending limb of the nephron is permeable to water (a) True Which of the following vessels takes blood out of the renal corpuscle and returns (b) False 7. it to the bloodstream? ?Explanation / Answer
4. (d) All of the above.
Na+ reabsorption occurs by a protein- sodium/ potassium ATPase into peritubular capillaries that requires energy. Sodium/ potassium pump pushes out 3 Na+ ions and pull inside 2 K+ ions. Chloride ions follow these Na+ ions and are also transported out of tubule. K+ ion channels lead to diffusion of K+ into the tubule. PCT cells become negatively charged. A gradient is created which increases Na+ uptake.
Cl- ions follow transported Na+ and move out of tubule.
Reabsorption of water occurs by osmosis. Water moves from region of its high concentration to region of low concentration(peritubular capillaries).
5. (d)
Vasoconstriction of efferent arteriole leads to decrease in blood flow out of glomerulus, glomerular hydrostatic pressure increases and GFR increases
6. False. The ascending loop is impermeable to water and descending loop is permeable. The descending part is permeable in order to allow simple diffusion. Water is reabsorbed in descending loop. Since the ascending part is impermeable, water remains inside and dilutes the urine and other solutes get reabsorbed.
7. (b) Efferent arteriole takes blood out of the corpuscle and returns it to bloodstream.
Peritubular capillaries are those where useful substances are reabsorbed between blood and internal lumen of nephron.
Vasa recta is used for supplying blood in medulla.
Afferent arteriole takes blood towards the kidneys.
8. (d) ADH acts on distal convoluted tubule and collecting duct because these are the two parts of nephron that have receptors for ADH. Hence ADH does not act on other parts of the nephron.
9. (a) Trigone is the region inside the bladder bound by two urethral openings and urethra.
Mucus layer protects bladder from toxins present in urine.
Detrusor muscle is an involuntary muscle that relaxes when urine is being collected and contracts when urine is being released.
Transitional epithelium or urothelium helps bladder to stretch to contain more volume of urine.
10. (a) True. Stretch receptors become stimulated when urine is being collected and the stimulus reaches spinal cord and micturition( passing out of urine) reflex is triggered.