Renal Blood Supply/Regulation of Blood Flow

Question 1

What artery provides blood supply to the kidney?

Answer 1

Renal arteries

Question 2

The amount of blood filtered by the glomerulus per unit of time is _____________

Answer 2

GFR

Question 3

What are the 2 factors affecting renal blood flow?

Answer 3

• BP gradient
• Renal vascular resistance (RVR)

Question 4

The BP gradient affecting RBF is between which vessels?

Answer 4

Renal a and v

Question 5

With a high RVR, RBF is _________ (lower/higher)

Answer 5

Lower

Question 6

List 3 factors that can affect Renal Vascular Resistance

Answer 6

• blood viscosity
• vessel length
• vessel diameter
• restriction/obstruction

Question 7

Vasoconstriction of renal vessels would (increase/decrease) RVR

Answer 7

increase, thus decrease blood flow

Question 8

________________ is responsible for Vasodilation and vasoconstriction

Answer 8

Smooth muscle

Question 9

Which layer of the smooth muscle is associated with vasodilation and vasoconstriction?

Answer 9

t. Media

Question 10

Why is regulation of renal blood flow crucial?

Answer 10

To maintain renal function and urine production to keep homeostasis

Question 11

Which part of the distal convoluted tubule physically contacts the afferent arteriole and Juxtaglomerular cells?

Answer 11

Macula densa

Question 12

What are the 2 mechanisms that regulate RBF?

Answer 12

intrinsic and extrinsic

Question 13

List the 2 intrinsic RBF regulation mechanisms

Answer 13

• Myogenic Mechanism
• Tubular Glomerular mechanism

Question 14

The extrinsic SNS and RAAS will do what to BP and RBF?

Answer 14

increase them

Question 15

Which extrinsic mechanism of RBF will decrease it BP and RBF?

Answer 15

The Atrial Natriuretic Peptide (ANP) mechanism

Question 16

At normal conditions, what ion is found more on the inside of SR?

Answer 16

Calcium

Question 17

The myogenic mechanism of regulation of RBF is in case of what systemic condition?

Answer 17

High BP = high RBF and GFR

Question 18

What activates the sodium channel, which causes vasoconstriction, in the myogenic mechanism?

Answer 18

Stretch of arteriole myocytes

Question 19

The overall goal of the myogenic mechanism is to?

Answer 19

decrease RBF and GFR

Question 20

The myogenic mechanism is _______________ (extrinsic/intrinsic)

Answer 20

Intrinsic

Question 21

What makes Ca move to the SR, which in turn, causes vasodilation in the myogenic mechanism?

Answer 21

No movement of Sodium due to no stretch of myocytes (vasodilation)

Question 22

What are the NaCl sensory cells that are sensitive to abnormal Na and Cl concentrations in the Tubular-Glomerular feedback mechanism?

Answer 22

Macula Densa cells

Question 23

What do the macula densa cells release in response to the high Na/Cl concentrations?

Answer 23

Adenosine

Question 24

What may cause an excess filtrate of Na and Cl concentration?

Answer 24

High GFR due to high BP

Question 25

Adenosine causes what in the tubular glomerular feedback mechanism?

Answer 25

Vasoconstriction to decrease RBF and GFR

Question 26

If the macula densa sense lower Na and CL concentrations, what fo they produce?

Answer 26

Prostacyclin and NO

Question 27

Prostacyclin and NO cause VD or VC?

Answer 27

Vasodilation to increase BP and RBF/GFR

Question 28

With low BP, Prostacyclin and NO can aslo cause the release of ?

Answer 28

renin by the juxtaglomerular cells to activate the RAAS

Question 29

Is the release of renin an extrinsic or intrinsic mechanism?

Answer 29

Extrinsic

Question 30

The activation of the SNS would do what to HR and BP?

Answer 30

Increase it

Question 31

The SNS activates what gland in response to low BP?

Answer 31

Adrenal gland to produce Epi and NE

Question 32

What does Epi and NE activate?

Answer 32

Juxtaglomerular cells which release renin and increase RBF and GFR via RAAS

Question 33

In the RAAS extrinsic mechanism, which organ produces the Angiotensinogen?

Answer 33

Liver

Question 34

Angiotensin-converting enzyme (ACE) is produced by?

Answer 34

Lungs

Question 35

What converts Angiotensinogen into Angiotensin I ?

Answer 35

Renin

Question 36

Describe the function of ACE

Answer 36

Convert Angiotensin I into Angiotensin II

Question 37

List the actions of Angiotensin II

Answer 37

- activates pituitary - activates adrenal gland - regulates the nephron - regulates systemic BP

Question 38

The pituitary releases ADH to act on which structure of the nephron?

Answer 38

Collecting duct (increases water permeability)

Question 39

Where are the osmoreceptors that are activated by the Angiotensin II to cause thirst?

Answer 39

In the hypothalamus

Question 40

In the RAAS, what does the adrenal gland produce in response to the low BP/RBF/GFR?

Answer 40

Aldosterone

Question 41

How does aldosterone increase RBF and GFR in the RAAS?

Answer 41

acts on the distal convoluted tubule by increasing salt reabsorption (and thus water)

Question 42

Where does Angiotensin II act on the nephron to increase sodium permeability?

Answer 42

Proximal convoluted tubule

Question 43

How does angiotensin II cause vasoconstriction of an artery ?

Answer 43

binds to its receptor in the systemic artery

Question 44

when blood pressure and RBF are high, what does the heart release to reduce the RBF?

Answer 44

Atrial Natriuretic Peptide (ANP)

Question 45

List the 3 ways ANP will regulate RBF

Answer 45

- binds to its own receptors to cause VD - causes VD on afferent arteriole - acts on proximal convoluted tubule to reduce sodium reabsorption

Question 46

Will ANP increase or decrease urine prodcution?

Answer 46

Increase

Question 47

What can ANP inhibit?

Answer 47

RAAS and Aldosterone secretion