Proximal Tubular Function

Front 1

60-70% of glomerular filtrate is absorbed in ? Why

Back 1

Proximal tubule, has high water permeability

Front 2

Reabsorbed water and solutes are readilly drawn into _ because blood pressure is low while oncotic pressure is high

Back 2

Peritubullar capillaries

Front 3

Tubuloglomerular feedback

Back 3

If there is unusually large amount of filtrate formed, peritubular capillary pressure will drop further and cause even more reabsorption

Front 4

Filtered 800, reabsorbed 800, secreted 0 - which substance

Back 4

Glucose

Front 5

In glomerular failure

Slit membrane-

Basement membrane

Back 5

Albumin and protein

RBC

Front 6

Metabolites elevated in blood in renal failure

Back 6

Creatinine - inversely related to functional kidney mass

Urea (uric acid, ammonia)

Front 7

Amino acids in urine

Back 7

High protein meals or proximal tubular damage

Front 8

Peptides in urine

Back 8

High protein meals or proximal tubular damage

Front 9

Glucose in urine

Back 9

Hyperglycemia or proximal tubular damage

Front 10

Phosphate in urine

Back 10

Normal but increased with proximal tubular damage

Front 11

Ketones in urine

Back 11

Low carb diet or DKA

Front 12

Leukocytes in urine

Back 12

UTI (also nitrites)

Front 13

Billirubin in urine

Back 13

Jaundice

Front 14

60-70% of NaCl is reabsorbed _

Back 14

Iso osmotically

Front 15

Virtually all _ are reabsorbed

Back 15

Glucose and amino acids

Front 16

_ not reabsorbed and becomes concentrated in remaining water

Back 16

Creatinine

Front 17

_ left behing by reabsorbed water

Back 17

Inulin and creatinine

Front 18

Example of non reabsorbed plus secreted substance

Back 18

PAH (para amino hyaurine)

Front 19

_ are only reabsorbed in proximal tubule

Back 19

Most organics and bicarb

Front 20

_ reabsorbed along nephron

Back 20

NaCl

Front 21

_ reabsorbed more proximally and secreted more distally

Back 21

K

Front 22

In proximal tubule Na is primarily reabsorbed by _

How else does Na enter?

Back 22

Na/H exchange and basolateral Na/K ATPase

As cotransport with glucose, some amino acids , nucleic acids and some vitamins

Front 23

Early proximal tubule absorbs Cl by _

Back 23

Paracellular pathway driven by lumen negative potential created by Na absorption

Front 24

Late proximal tubule absorbs Cl

Back 24

Exchanges for other anions in apical membrane and Cl is contransported out of cell with K at basolateral membrane

Front 25

Alkalinizing the forming urine (increases, decreases) kidneys ability to excrete

Back 25

Increases

Front 26

Acidifying the forming urine will (increase, decrease) ability to excrete weak bases

Back 26

Increase

Front 27

65% of reabsorption occurs in _

25% occurs in _

10% _

Back 27

Proximal tubule

Ascending limb of medullary loop

10% after that

Front 28

Proximal tubular defect reducing all proximal transport processes

Back 28

Fanconis syndrome

Front 29

Typical organic solute, cotransported with Na across apical membrane and leaves by facilititive diffusion at basolateral membrane

Back 29

Glucose

Front 30

When do you see glucose in urine

Back 30

IN HYPERGLYCEMIA --> Na glucose cotransporter is exceeded and in Fanconis syndrome

Front 31

Amino acids /peptides in urine

Back 31

After high protein meals if Tm for endocytosis is exceeded or due to cotransport defficiency

Front 32

Large proteins in urine

Back 32

After glomerular damage but also in Tamm Horsfall disease where medullary cells excrete Tamm Horsfall protein

Front 33

Small proteins in urine

Back 33

Amyloid protein disease (Tm of endocytosis exceeded, Fanconis syndrome and rare syndrome affecting only endocytosis

Front 34

Stimulates proximal tubular Na reabsorption by increasing Na/H exchange

Back 34

Angiotensin II

Front 35

Stimulates Na, K ATPase in all nephron segments reducing intracellular Na and increasing driving force of Na to enter, causes some stimulation of Na transport in every part of nephron includin Na H exchange in proximal tubule

Back 35

Aldosterone

Front 36

Kidney is innervated by what type neurons

Back 36

Dopaminergic and adrenergic

Front 37

Which innervation increases proximal tubule Na reabsorption and release of renin

Back 37

Sympathetic stimulated by volume depletion or reduced BP

Front 38

_ INHIBITS proximal tubule Na reabsorption, especially potent in inducing diuresis in patients who are receiving diuretic, can be significant drug interaction

Back 38

Dopamine

Front 39

_ can induce polyuria if not reabsorbed

Back 39

Glucose, mannitol