Chapter 14 Renal

Question 1

Functions of Kidneys

Answer 1

• regulation of water, inorganic ion balance, and acid-base balance
• removal of metabolic waste from blood and excretion in urine
• removal of foreign chemicals from blood and excretion in urine
• gluconeogenesis
• production of hormones/ enzymes

Question 2

Ureters

Answer 2

transport urine from kidneys to bladder

Question 3

Bladder

Answer 3

stores urine until voided from body

Question 4

Urethra

Answer 4

carries urine from bladder to the outside of the body

Question 5

Nephrons

Answer 5

structural and functional units of kidney

Question 6

Renal corpuscle

Answer 6

initial filtering component

Question 7

Tubule

Answer 7

selective reabsorption of things the body needs, come out of renal corpuscle

Question 8

Glomerulus/ glomerular capillaries

Answer 8

compact tuft of interconnected capillary loops

Question 9

Bowman’s Capsule

Answer 9

fluid-filled capsule coming off of the glomerulus

Question 10

Podocytes

Answer 10

single celled inner layer of glomerular filtration barrier, encapsulate basement membrane

Question 11

Mesangial cells

Answer 11

modified smooth muscle cells in the glomerulus, help regulate blood flow in glomerulus

Question 12

Glomerular filtration rate

Answer 12

volume of plasma filtered from glomerular capillaries into Bowman’s space per unit time

Question 13

Peritubular capillaries

Answer 13

most of filtrate is reabsorbed between or across renal tubule cells into these

Question 14

Juxtamedullary Nephrons

Answer 14

• long loops of Henle
• generating an osmotic gradient in the medulla, reabsorption of water
• contain renal corpuscles that are between cortex and medulla
• 15% of all nephrons
• close to vasa recta (long blood vessels running alongside loops of Henle)

Question 15

Cortical Nephrons

Answer 15

• most nephrons
• short/ no loops of Henle
• do not contribute to hypertonic medullary interstitium

Question 16

Juxtaglomerular cells

Answer 16

when stimulated by decrease in stretch, secrete renin (enzyme that influences sodium balance and blood pressure)

Question 17

Macula densa

Answer 17

patch of specialized cells in the wall of ascending loop of Henle, sense changes in NaCl content of the filtrate, help regulate sodium balance and blood pressure

Question 18

Juxtaglomerular apparatus (JGA)

Answer 18

combination of macula densa and juxtaglomerular cells

Question 19

Glomerular Filtration

Answer 19

bulk-flow passive process in which hydrostatic pressure forces water and all low-molecular-weight substances through a filtration border

Question 19

Basic Renal Processes and Urinary Excretion

Answer 19

amount excreted = (amount filtered+amount secreted-amount reabsorbed)

Question 20

Glomerular Filtration Rate

Answer 20

volume of fluid filtered from the glomeruli into Bowman’s space per unit time, directly proportional to the membrane permeability and surface area

Question 21

Reabsorption

Answer 21

movement of a substance from the fluid in the tubular lumen into peritubular capillary

Question 22

Most abundant cation in filtrate

Answer 22

Na+

Question 22

Na+ reabsorption

Answer 22

an active process occurring in all tubular segments except descending loop of Henle

Question 23

Tubular secretion

Answer 23

substances move from peritubular capillaries into tubular lumen, important for - disposing of drugs - eliminating undesired substances - removing excess K+ - controlling blood pH

Question 24

Renal Clearance

Answer 24

volume of plasma from which that substance is completely removed by kidneys per unit time

Question 25

Hyperosmotic Medullary Interstitium

Answer 25

- the countercurrent anatomy of the loop of Henle of juxtamedullary nephrons - reabsorption of NaCl in ascending limbs of those loops - impermeability to water of those ascending limbs - trapping of urea in medulla - hairpin loops of vasa recta to minimize washout of hyperosmotic medulla

Question 26

Dilute Urine

Answer 26

urine becomes dilute as it moves up through the ascending limb of the loop of Henle due to the reabsorption of NaCl and impermeability of water in these ascending limbs

Question 27

Concentrated Urine

Answer 27

ADH uses cAMP second-messenger systems to cause the insertion of aquaporins into the apical membranes of the collecting ducts

Question 28

Vasopressin

Answer 28

controls amount of urea that gets reabsorbed, only acts on collecting ducts

Question 29

Parathyroid hormone

Answer 29

reduces phosphate reabsorption in the proximal tubule, increases calcium reabsorption in distal convoluted tubule and early in cortical collecting duct

Question 30

Diuretics

Answer 30

used to prevent/ reverse the renal retention of Na+ and water, increase volume of urine excreted

Question 31

Osmotic diuretics

Answer 31

filtered but not reabsorbed thus retaining water in the urine

Question 32

Loop diuretics

Answer 32

act on ascending limb of the loop of Henle to inhibit first step in Na+ reabsorption in this segment- cotransport of Na+

Question 33

Potassium-sparing diuretics

Answer 33

inhibit Na+ reabsorption in the cortical collecting duct without increasing K+ secretion there