Renal System Part 3

Question 1

Vasopressin (ADH) and Urine Formation

Answer 1

Vasopressin (ADH) determines the volume and concentration of urine. Main target is CD.

-Aquaporins
-Urea reabsorption

Question 2

Would osmolarity increase or decrease with ADH?

Answer 2

Increase

Question 3

Osmoreceptors

Answer 3

More water intake & no change in sodium= more water excretion

• Sensory receptors
• Fire APs in response to changes in PLASMA OSMOLARITY
• Reflexively control ADH secretion

Question 4

Baroreceptors

Answer 4

Less water intake & no change in
sodium= less water excretion

• Sensory receptors
• Fire APs in response to changes in
  BLOOD PRESSURE
• Reflexively control ADH secretion

Question 5

Sodium Loss and GFR

Answer 5

Decreased BP leads to increased vasoconstriction of afferent arterioles via SNS

Decreased GFR saves water and salt

Question 6

Renin-Angiotensin System

(Expect lots of exam questions on this)

Answer 6

Aldosterone – hormone that stimulates Na+ reabsorption from the DCT and COLLECTING DUCT
* Renin – enzyme that makes
Angiotensin I

• Angiotensin I= Angiotensin II in the
  plasma
• Angiotensin II binds to receptors in the adrenal cortex to stimulate the release of aldosterone

Question 7

Draw out the Renin-Angiotensin System

Answer 7

Memorize this

Question 8

Atrial Natriuretic Peptide and Sodium Excretion

Answer 8

• ANP – secreted from the heart
• Stimulus is distention of the atria
• Dilates afferent arterioles
• Constricts efferent arterioles
• Increases Na+ absorption in
  tubules

Draw out.

Question 9

Summary of Renal Tubule Functions

Answer 9

(Memorize these slides)

Question 10

Diuretics

Answer 10

Promote the loss of Na+ and water

Alcohol acts like a diuretic by inhibiting the release of Vasopressin from the pituitary gland

Question 11

Pyelitis

Answer 11

Infection of the renal pelvis usually occurs from bacteria