1.7 Physiology: Basics Urine Formation

Question 1

% body water

Answer 1

60-40-20

Total water-Intracellular-Extracellular

Question 2

Renal Clearance

Answer 2

UV/P

Question 3

Excretion rate

Answer 3

UV

Question 4

Clearance<GFR

Answer 4

Reabsorption

Question 5

Cx>GFR

Answer 5

secretion

Question 6

Clearance = GFR

Answer 6

No net secretion or reabsorbed–>Inulin

Question 7

What is inulin

Answer 7

Used to calculate GFR

Question 8

Normal GFR

Answer 8

90-135 ml/min

Question 9

Creatinine

Answer 9

Freely filtered. Not absorbed. Estimates GFR

Question 10

RPF

Answer 10

Blood–>Glomeruli

Blood

Question 11

How is effective renal plasma flow estimated

Answer 11

para-aminohippuric acid (PAH) clearance because it is both filtered and actively secreted in proximal tubule. –>All PAH to kidney secreted

Question 12

Equation for RBF

Answer 12

RPF/1-HCT

Question 13

Filtration fraction

Answer 13

Portion of RPF filtered across the glomerular capillaries

FF=GFR/RPF

Question 14

Normal FF

Answer 14

20%

Question 15

NSAIDs effect on glomerular filtration

Answer 15

Constrict the afferent arteriole. Decrease RBF, decrease GFR. FF No change

Question 16

What does Ang II do to the efferent arteriole?

Answer 16

Constrict the efferect arteriole. decrease in RBF and increase GFR. FF increase

Question 17

How can Ang II be inhibited?

Answer 17

ACEI–>Dilate efferent arteriole

FF decrease

Question 18

Constriction of afferent arteriole causes what to GFR, RBF, and FF

Answer 18

Decrease GFR
Decrease RBF
No change FF

Question 19

Increase plasma protein concentration: GFR, RBF, and FF

Answer 19

No change to RBF
Decrease GFR
Decrease FF

Question 20

Decrease Plasma Protein conc: GFR, RBF, and FF

Answer 20

GFR increase
FF increase
RBF unchanged

Question 21

Ureter stone: GFR, RBF, and FF

Answer 21

GFR decrease

FF decrease

Question 22

Filtered load

Answer 22

GFR*Plasma concentration

Question 23

Excretion rate

Answer 23

UV

Question 24

Reabsorption

Answer 24

Filtered-excreted

Question 25

Secretion=

Answer 25

Secreted-filtered

Question 26

Glucose Clearance: How is it reabsorbed, what transporter?

Answer 26

Reabsorbed in prox tubule by Na+/glucose cotransport

Question 27

What are the two urinary buffers?

Answer 27

phosphate and creatinine

Question 28

Pt ways 100kg what is the amount of ECF?Plasma volume

Answer 28

20 ECF–> Plasma 5L

Question 29

Glucose saturation

Answer 29

350mg/dL

Question 30

Na+reabsorption is directly related to what

Answer 30

O2 consumption

Question 31

Affect of ANP, atrial natriuretic peptide on RBF

Answer 31

It cases vasodilation of afferent arterioles and lesser extent vasoconstriction of efferent arteriole–>Increase RBF

Question 32

PAH Filtered load

Answer 32

Filtered load of PAH increases in direct proportion to plasma PAH conc

Question 33

Secretion of PAH

Answer 33

Low plasma conc–>Secretion rate increases as plasma conc increases
Tm–>Plateau

Question 34

When does the exretion PAH curve become parallel to filtration

Answer 34

When Tm is reached

Question 35

What has the highest clearance: PAH; K+;Inulin:Urea: Na:Glucose

Answer 35

PAH>K+>Inulin>Urea>Na>Glucose

Question 36

Autoregulation of renal flow: 3 ways

Answer 36

• Myogenic response of arterioles

- Tubular feedback- Macula densa cells sense distal tubule flow and relase paracrines that affect afferent arterioles

Question 37

Increase in bowman’s capsule pressure? GFR?

Answer 37

Decrease GFR