Renal 5

Question 1

Regulation of Tubular reabsorption Essential to maintain a precise balance between ____ and ______

Answer 1

GFR and tubular reabsorption

Question 2

T/F: Reabsorption of some solutes can be individually adjusted.

Answer 2

True

Question 3

Tubular reabsorption is controlled by what 3 mechanisms?

Answer 3

Local Control Mechanisms
Nervous System
Endocrine System

Question 4

What are the 2 local control mechanisms of tubular reabsorption?

Answer 4

Tubuloglomerular Feedback Response (TGF)

Glomerulotubular Balance (GTB)

Question 5

______:
Autoregulation of GFR.
Keeps GFR constant
Afferent and Efferent arteriolar resistance related to flow rate of NaCl by macula densa

Answer 5

TGF Response:

Question 6

GFR _____ leads to ______ NaCl to macula densa leads to TGF response _______ GFR

Answer 6

increase; increase; decreases

Question 7

_______:
Autoregulation of PT reabsorption rate
PT reabsorption rate related to tubular load
As tubular LOAD increases, rate of REABSORPTION increases.
Depends on changes in peritubular capillary and renal interstitial fluid Starling’s forces.

Answer 7

Glomerular Tubule Balance (GTB)

Question 8

Due to GTB, As tubular LOAD ______, rate of REABSORPTION increases.

Answer 8

increases

Question 9

Due to GTB, As tubular LOAD increases, rate of REABSORPTION _______.

Answer 9

increases

Question 10

Together the TGF and GTB help to prevent overloading of the distal tubule segment when GFR ______ due to pressure changes or other disturbances

Answer 10

increases

Question 11

An increase in GFR, leads to an ______ in reabsorption rate of the proximal tubule

Answer 11

Increases

Question 12

If ____ is not present, an increase in GFR will lead to no reabsorption causing the urine volume to greatly increase

Answer 12

GTB

Question 13

____ is increased salt excretion

Answer 13

Natriuresis

Question 14

____ is increased water excretion

Answer 14

Diuresis

Question 15

Small increases in _____ can cause marked increases in urinary Na+ and H2O excretion.

Answer 15

MAP

Question 16

Small increases in MAP can cause marked increases in urinary ____ and _____ excretion.

Answer 16

Na+ and H2O excretion

Question 17

Normal kidney function and pressure natriuresis mechanisms assure that large changes in salt and water intake accommodated with only minor changes in what 3 things?

Answer 17

ECF volume
CO
MAP

Question 18

What 5 hormones regulate tubular reabsorption?

Answer 18

• aldosterone
• angiotensin II
• antidiuretic hormone (ADH)
• atrial natriuetic peptide (ANP or ANF)
• parathyroid hormone

Question 19

What hormones Stimulates Na+ reabsorption and K+ Secretion?

Answer 19

Aldosterone

Question 20

What causes there to be a slow onset response for aldosterone?

Answer 20

Steroid hormones have to cross cell membrane and alter gene expression

Question 21

Why causes there to be a long duration of response from aldosterone?

Answer 21

Long half life

Question 22

What 2 conditions cause an increase of aldosterone secretion?

Answer 22

Increased plasma K+
Angiotensin II
(changes associated with Na+and volume depletion or low blood pressure)

Question 23

What 2 conditions cause an decrease of aldosterone secretion?

Answer 23

Atrial natriuretic factor (ANF)

Increased Na+ concentration (osmolarity; weak)(changes associated with increased Na+ and volume or high blood pressure)

Question 24

Increases H+ secretion by intercalated cells of late distal & cortical collecting tubule membrane: excess levels may cause metabolic alkalosis.
Increases Na+ reabsorption and K+ secretion by sweat and salivary glands.
Increases Na+ absorption by intestinal (colon) mucosa

Answer 24

Aldosterone

Question 25

Aldosterone causes increased ____ secretion by intercalated cells of late distal & cortical collecting tubule membrane: excess aldosterone levels may cause metabolic alkalosis.

Answer 25

H+

Question 26

Aldosterone Increases Na+ reabsorption and K+ secretion by ____ and _____ glands

Answer 26

sweat and salivary glands.

Question 27

Aldosterone Increases ____ absorption by intestinal (colon) mucosa

Answer 27

Na+

Question 28

Hormone: Major Regulator of Na+ and Water Reabsorption; increases Bicarb reabsorption and increases H+ secretion

Answer 28

Angiotensin II

Question 29

Stimulates aldosterone production. Directly increases Na+ reabsorption (proximal, loop, distal, collecting tubules). Constricts efferent arterioles and enhances peritubular capillary reabsorption: -Decreased PC in peritubular capillaries -Increased Colloid osmotic pressure in capillary in peritubular capillaries (Increases PG which Increases the filtration fraction)

Answer 29

Angiotensin II

Question 30

Hormone: Increases Water Reabsorption of the apical membrane by aquaporin-2 channels

Answer 30

ADH

Question 31

What 2 things stimulate ADH release?

Answer 31

Increased ECFosm | Decreased MAP

Question 32

What 2 things stimulate Angiotensin II release?

Answer 32

Decreased MAP | Decreased ECFvol

Question 33

Increases H2O permeability via activation of Gαs Protein linked receptor Activates cAMP Increases the synthesis and insertion of AQP-2 into luminal membrane.

Answer 33

ADH

Question 34

Where does ADH act?

Answer 34

Late Distal Tubule (DT) and Collecting Duct CD

Question 35

Where does Ang II act?

Answer 35

Most nephron segments

Question 36

Where does Aldosterone act?

Answer 36

Principal cells of collecting duct

Question 37

Hormone: Increase GFR and↓ Na+Reabsorption (↑ Na+ Excretion)

Answer 37

ANP

Question 38

What stimulates ANP?

Answer 38

Cardiac atria in response to stretch

Question 39

Directly inhibits Na+and H2O reabsorption in PT Increases GFR (dilates afferent, constricts efferent arterioles). Inhibits renin release and aldosterone formation. Helps to minimize blood volume expansion (CHF).

Answer 39

ANP

Question 40

Constricts arterioles. Stimulates renin release. Decreases GFR and renal blood flow. Directly stimulates Na+reabsorption via α receptors on tubule epithelial cells in PT and TAL.

Answer 40

Sympathetic Nervous System

Question 41

Decreases Na+ and H2O Excretion

Answer 41

SNS

Question 42

``` ____ is critical for: ⁻Normal cell function ⁻Neural transmission ⁻Membrane excitability ⁻Bone structure⁻Blood Coagulation ⁻Intracellular signaling ```

Answer 42

Ca ++

Question 43

The majority of Ca is in _____

Answer 43

bones

Question 44

What form of Ca is tightly regulated?

Answer 44

ECF Ca ++

Question 45

What form of Ca is the most important for functions in the body?

Answer 45

Ionized Ca++

Question 46

How much of plasma Ca ++ is filtered?

Answer 46

60%

Question 47

How much of filtered Ca++ is reabsorbed in the PCT?

Answer 47

65%

Question 48

How much of Ca++ is reabsorbed in loop of Henle in TAL?

Answer 48

25-30%

Question 49

How much of Ca++ is reabsorbed in Distal and collecting tubule?

Answer 49

4-9%

Question 50

How much of Ca++ is excreted?

Answer 50

1%

Question 51

____ Regulates Ca++Reabsorption in TAL and DT

Answer 51

PTH

Question 52

What is the stimulus for PTH release?

Answer 52

Low Ca++

Question 53

Where is PTH secreted from?

Answer 53

Chief cells of PTG

Question 54

_____ transport: 50% by para-cellular bulk flow; passive Favored by +8 mV luminal charge 50% transcellular; entry passive

Answer 54

Ca++

Question 55

The primary transport of Ca++ is ____ by PTH?

Answer 55

Increased