Renal Part II

Question 1

Changes in what ion correspond to extra cellular volume changes?

Answer 1

Na+

Question 2

Low Na+ indicates what about plasma volume?

Answer 2

Low plasma volume

Question 3

How does the cardiac system compensate for decreased Na+?

Answer 3

Decreased firing of baroreceptors and activation of sympathetic nervous system

Question 4

Decreased plasma volume and venous return

Answer 4

Decreased Na+

Question 5

How do the kidneys compensate for decreased Na+?

Answer 5

Constricting afferent arterioles, decreasing Na+ and H2O excretion

Question 6

What does aldosterone do to the distal convoluted tubule and cortical collecting duct?

Answer 6

Increased Na+ reabsorption

Question 7

Where does aldosterone act?

Answer 7

Distal tubule and cortical collecting duct

Question 8

How does aldosterone increase Na+ reabsorption?

Answer 8

Increased synthesis of Na/K pumps

Question 9

What is the main goal of RAAS?

Answer 9

Raise blood pressure

Question 10

What does RAAS stand for?

Answer 10

Renin-Angiotensin-Aldosterone System

Question 11

Where does renin come from?

Answer 11

Made by the JG cells in the kidney

Question 12

What is the rate limiting step of RAAS?

Answer 12

Renin production

Question 13

What does renin do?

Answer 13

Catalyzes angiotensinogen to angiotensin i

Question 14

What catalyzes angiotensin i to angiotensin ii?

Answer 14

ACE

Question 15

What does ACE stand for?

Answer 15

Angiotensin converting enzyme

Question 16

What produces ACE?

Answer 16

Capillary endothelium

Question 17

What does angiotensin ii promote?

Answer 17

Increased aldosterone secretion and systemic vasoconstriction of arteries

Question 18

Which member of the RAAS is produced in excess?

Answer 18

Angiosinogen

Question 19

How do the renal sympathetic nerves stimulate renin production?

Answer 19

they directly innervate the JG cells, increased sympathetic activity —> increased activity of JG cells

Question 20

Which cells are referred to as the intrarenal barorecptors?

Answer 20

JG cells

Question 21

What do JG cells respond to?

Answer 21

Arteriole stretching - less stretched afferent arteriole = more renin secretion

Question 22

What is the purpose of the macula densa cells?

Answer 22

Sense Na+ content in tubular fluid and communicate with JG cells

Question 23

What does the atrial natriuretic peptide (ANP) do?

Answer 23

Decreases blood pressure by increasing Na+ secretion

Question 24

How does ANP increase blood pressure?

Answer 24

Inhibits Na+ reabsorption and increases GFR

Question 25

What stimulates ANP?

Answer 25

Atrial distension from increased plasma volume

Question 26

What step of RAAS do ACE inhibitors (such as lisinopril) act on?

Answer 26

angiotensin i doesn't get converted to angiotensin ii

Question 27

What step of RAAS do angiotension i receptor blockers act on? (ex: losartan)

Answer 27

doesn't allow angiotensin i to convert to angiotensin ii

Question 28

Which medications are an example of an aldosterone receptor blocker?

Answer 28

epleronone and spironolactone

Question 29

What does furasamide (Lasix) do?

Answer 29

Inhibits the N/KCC transporter in the loop of Henle, decreases blood pressure (loop diuretic)

Question 30

What happens when the N/KCC transporter is blocked?

Answer 30

Ions can't get across, the medullary interstitial fluid is blocked and water can't get properly reabsorbed

Question 31

Where are osmoreceptors located?

Answer 31

hypothalamus

Question 32

What stimulates a decrease in osmoreceptor firing?

Answer 32

Increased H2O concentration in body (decreased osmolarity)

Question 33

How do osmoreceptors stimulate decreased ADH secretion?

Answer 33

decreased firing

Question 34

What does hyperkalemia promote?

Answer 34

Aldosterone release

Question 35

How does aldosterone regulate potassium?

Answer 35

Increased aldosterone results in increased potassium secretion and na+ reabsorption

Question 36

Aldosterone's effect on hypokalemia?

Answer 36

Decreased activity of aldosterne

Question 37

HCO3- reabsorption is paired with what?

Answer 37

H+ secretion

Question 38

What is the difference between metabolic and respiratory acidosis?

Answer 38

Metabolic is a decrease in blood pH, respiratory is an increase in CO2

Question 39

What causes metabolic acidosis?

Answer 39

Untreated diabetes or excess lactic acid

Question 40

How is metabolic acidosis compensated for?

Answer 40

Hyperventilation, increased renal secretion and excretion of H+, HCO3- reabsorption

Question 41

How is metabolic alkalosis caused?

Answer 41

Persistent vomiting - note that this is rare

Question 42

How is metabolic alkalosis compensated for?

Answer 42

Hypoventilation, increased renal secretion and excretion of HCO3-, decreased H+ secretion

Question 43

How is respiratory acidosis caused?

Answer 43

COPD, sleep apnea, airflow obstruction

Question 44

What compensates for respiratory acidos?

Answer 44

Increased renal H+ secretion and excretion, increased HCO3- reabsorption

Question 45

When would respiratory alkalosis be seen?

Answer 45

During a panic attack or when hyperventilating

Question 46

How is respiratory alkalosis compensated for?

Answer 46

Increased renal secretion and excretion of HCO3-, decreased H+ secretion