Urinary 2

Question 1

measures the volume of plasma cleared of a. substance in a given time

Answer 1

renal clearance

Question 2

clearance equation

Answer 2

RC = (urine concentration x urine flow rate) / plasma concentration

Question 3

closely approximates GFR and is useful for assessing kidney function

Answer 3

inulin clearance

Question 4

• involves active or passive transport of substances like H+ ions, penicillin, and K+ ions into the filtrate
• plays a role in controlling the body’s pH balance

Answer 4

tubular secretion

Question 5

• vasa recta capillaries exchange water for salt as they travel down into the medulla
• system ensures ECF retains high salt levels for water movement out of the nephron

Answer 5

countercurrent exchange mechanism

Question 6

• maintains high medullary concentration to aid water reabsorption from the nephron
• saltier medulla pulls water out of the descending limb, while salts are pumped out in the descending limb

Answer 6

countercurrent multiplier

Question 7

countercurrent mechanisms

Answer 7

• countercurrent multiplier
• countercurrent exchange mechanism

Question 8

what hormone promotes active tubular secretion of potassium and reabsorption of sodium ions in the distal convoluted tubule and collecting ducts

Answer 8

aldosterone

Question 9

what area of the nephron is responsible for the reabsorption of the most water from the filtrate as well as most nutrients

Answer 9

proximal convoluted tubule

Question 10

true or false:

Under normal conditions, the proximal convoluted tubule (PCT) reabsorbs nearly all of the glucose, lactate, and amino acids in the filtrate and 65% of the Na+ and water.

Answer 10

true

Question 11

the kidney are stimulated to produce renin by

Answer 11

a decrease in the blood pressure

Question 12

contains fluid that becomes more concentrated as it moves down into the medulla

Answer 12

descending limb

Question 13

effect of ADH on cells of the CD

Answer 13

causes aquaporins to be inserted into apical membranes

Question 14

true or false:

Filtrate becomes less concentrated as it flows down the medullary collecting ducts, toward the renal pelvis.

Answer 14

false

Question 15

why does alcohol act as a diuretic

Answer 15

inhibits the release of ADH

Question 16

• 125ml of filtrate is formed each minute by pushing plasma across the fenestrae of glomerular capillaries into the proximal convoluted tubule.
• Most objects are too large to pass through the small (7nm) barrier
• Plasma proteins and RBCs (>7nm) remain in the capillary, while small hormones and minerals (<7nm) pass through.

Answer 16

filtration membrane

Question 17

consists of the glomerulus and bowman’s capsule

Answer 17

renal corpuscle / filtration membrane

Question 18

forces at the filtration membrane

Answer 18

• glomerular blood pressure (GP)
• colloid osmotic pressure (COP)
• capsular hydrostatic pressure (CP)

Question 19

net filtration pressure (NFP) =

Answer 19

Glomerular Pressure - (Colloid Osmotic Pressure + Capsular Hydrostatic Pressure)

NFP = GP - (COP + CP), with GP pushing water and solutes out, while COP and CP push in the opposite direction.

Question 20

filtration will still occur as long as

Answer 20

glomerular blood pressure is high enough

Question 21

how much water is reabsorbed in the nephron and how much is lost as urine

Answer 21

Approximately 123.75ml of water is reabsorbed in the nephron, leaving only 1.25ml/min lost as urine.

Question 22

plays a significant role in the collecting duct, concentrating urine up to 4 times.

Answer 22

ADH

Question 23

causes Na+ reabsorption and K+ secretion, leading to water reabsorption in the DCT

Answer 23

aldosterone

Question 24

impermeable to water, with Na+, K+, and Cl- transported out into interstitial fluid

Answer 24

ascending limb

Question 25

reabsorbs 15% of filtrate due to high interstitial solute concentration.

Answer 25

descending limb

Question 26

* 65% of filtrate is reabsorbed here, including amino acids, glucose, and ions like Na+, K+, and Cl-. * Water moves out by osmosis, transported against concentration gradients into peritubular capillaries.

Answer 26

proximal convoluted tubule

Question 27

involves vasoconstriction and dilation of afferent and efferent arterioles of the glomerulus

Answer 27

autoregulation

Question 28

directed by the macula densa of the distal convoluted tubule (DCT)

Answer 28

tubuloglomerular feedback mechanism

Question 29

monitor filtrate concentration and flow, adjusting GFR accordingly.

Answer 29

macula densa cells

Question 30

types of regulation of filtration

Answer 30

* intrinsic (autoregulation and tubuloglomerular feedback mechanism) * extrinsic (sympathetic stimulation (neural) and renin-angiotensin mechanism (hormonal))

Question 31

leads to arteriole dilation at rest, with norepinephrine causing vasoconstriction of renal vessels.

Answer 31

sympathetic stimulation

Question 32

aims to increase blood pressure by converting angiotensinogen to angiotensin II

Answer 32

renin-angiotensin mechanism

Question 33

is angiotensin a vasoconstrictor or a vasodilator

Answer 33

vasoconstrictor

Question 34

normal value of GP

Answer 34

55 mmHg

Question 35

typical COP value

Answer 35

30 mmHg

Question 36

typical CP value

Answer 36

15 mmHg

Question 37

increased blood pressure =

Answer 37

vasoconstriction of afferent arteriole

Question 38

decreased blood pressure =

Answer 38

vasodilation of afferent arteriole

Question 39

increased GFR =

Answer 39

rapid flow in DCT; vasoconstriction of afferent arteriole

Question 40

decreased GFR =

Answer 40

sluggish flow in DCT; vasodilation of afferent arteriole

Question 41

what is the stimulus for the renin-angiotensin mechanism

Answer 41

drop in blood pressure

Question 42

aldosterone release =

Answer 42

increase reabsorption of Na+ and water

Question 43

increased Na+ and water =

Answer 43

increased blood pressure

Question 44

ADH works most strongly in which areas of the nephron

Answer 44

DCT and CD

Question 45

decreased BP and increased K+ =

Answer 45

increased aldosterone = increased sodium and water retention

Question 46

increased BP and decreased K+ =

Answer 46

decreased aldosterone = decreased BP, increased urine output

Question 47

caused by ADH insufficiency

Answer 47

diabetes insipidus

Question 48

decreased BP = __ ADH and __ H2O retention

Answer 48

increased

Question 49

increased water retention =

Answer 49

increased BP, decreased urine

Question 50

increased BP = _____ ADH and _____ H2O retention

Answer 50

decreased ADH and decreased H2O retention

Question 51

decreased ADH and decreased H2O retention =

Answer 51

decreased BP, increased urine