Exam 12: Body Defenses

The clearance rate for a substance that is filtered and secreted but not reabsorbed is greater than the GFR.

Match the renal structures or activities with the correct characteristics, labelled a. through p. a.collecting tubules empty into this structure b.stores the urine c.passage of substances from the peritubular into the tubular lumen d.carries blood to the glomerulus e.tuft of capillaries that forms the filtrate f.passage of protein-free plasma into Bowman's capsule g.urine is forced through this structure by peristalsis h.collects the glomerular filtrate i.passage of substances from the tubular lumen into the peritubular capillaries j.functional unit of the kidney k.supplies the renal tissue with O₂ and nutrients l.carries blood from one capillary network to another capillary network m.tube through which urine leaves the body n.variable water and sodium reabsorption occur here under hormonal control o.responsible for the vertical osmotic gradient in the medulla of the kidney p.glucose and amino acid reabsorption occur here -tubular reabsorption

Match the effects, labelled a. through c., with the statements. (Options may be used more than once or not at all.) a.increases b.decreases c.has no effect on -Increased aldosterone secretion __________ Na⁺ reabsorption.

Match the urinary system features, labelled a. through e., with the correct characteristics. a.urea b.creatinine c.uric acid d.Na⁺ e.glucose -a detoxified ammonia compound

Body fluids are ____________________ at 300 mOsm/litre.

Which of these statements does NOT correctly describe juxtamedullary nephrons?

The secretion of aldosterone stimulates the tubular reabsorption of sodium and the tubular secretion of potassium.

Match the correct statements about sodium reabsorption, labelled a. through c., with the characteristics. (Options may be used more than once or not at all.) a.sodium reabsorption in the distal and collecting tubules b.sodium reabsorption in the proximal tubule c.sodium reabsorption coupled with chloride reabsorption in the loop of Henle -plays a pivotal role in the reabsorption of glucose, amino acids, H₂O, Cl^-, and urea

The glomerular filtrate contains only substances that are not needed by the body.

The osmolarity of the medullary interstitial fluid always equilibrates with the descending limb of the loop of Henle.

In the kidney, blood is filtered in the cortex, drains through the renal pelvis into the renal medulla, and from there travels in the ureter to the urinary bladder.

Which statement does NOT apply to vasopressin?

The renal threshold represents the maximum amount of a particular substance that the tubular cells are capable of actively reabsorbing per unit of time.

If the T_m for substance X is 200 mg/min, ____________________ (how much) of the substance will be reabsorbed at a plasma concentration of 200 mg/100 mL and a GFR of 125 mL/min? ____________________ (how much) of substance X will be excreted.

By reabsorption, substances leave the tubules of the nephrons and return to the blood in the ____________________.

Which statement does NOT correctly describe the proximal tubule?

Which statement correctly describes aldosterone secretion?

The specialized cells of the ____________________ within the ____________________ detect changes in the rate at which fluid is flowing past them through the tubule. In response, they secrete vasoactive chemicals that influence the GFR by making adjustments in the calibre of the ____________________ arterioles. This is known as the ____________________ feedback mechanism.

Match the renal structures or activities with the correct characteristics, labelled a. through p. a.collecting tubules empty into this structure b.stores the urine c.passage of substances from the peritubular into the tubular lumen d.carries blood to the glomerulus e.tuft of capillaries that forms the filtrate f.passage of protein-free plasma into Bowman's capsule g.urine is forced through this structure by peristalsis h.collects the glomerular filtrate i.passage of substances from the tubular lumen into the peritubular capillaries j.functional unit of the kidney k.supplies the renal tissue with O₂ and nutrients l.carries blood from one capillary network to another capillary network m.tube through which urine leaves the body n.variable water and sodium reabsorption occur here under hormonal control o.responsible for the vertical osmotic gradient in the medulla of the kidney p.glucose and amino acid reabsorption occur here -glomerular filtration

Because of countercurrent multiplication, the loop of Henle is able to establish a vertical osmotic gradient in the renal medulla ranging from 300 to 1,200 mosm/litre, despite the fact that the active salt pump of the ascending limb is able to produce only a 200 mosm/litre osmotic gradient at each horizontal level.