Integrative Physiology I

Question 1

Factors ↑ADH secretion: (7)

Answer 1

↑ ECF osmolarity
↓ blood volume (via ↓ ANP)
↓ blood pressure (directly via ↓ 
baroreceptor activity) 
Nausea
Hypoxia
Nicotine and Morphine
AngII

Question 2

Factors ↓ADH secretion: (5)

Answer 2

↓ ECF osmolarity
↑ blood volume (via ↑ ANP)
↑  blood pressure (directly via ↑ 
baroreceptor activity)
Ethanol
Cold

Question 3

Syndrome of Inappropriate ADH (SIADH) (2)

Answer 3

Excrete a Concentrated Urine

Too much ADH function

Question 4

SIADH

Most often seen in (4)

Answer 4

neurologic disease, head injury, lung

tumors or after major surgery.

Question 5

Excessive secretion of ADH causes (3)

Answer 5

hyponatremia,
decreased plasma osmolarity and urine
hyperosmolarity.

Question 6

SIADH
Sodium handling is intact and the only defect is in —
excretion.

Answer 6

water

Question 7

SIADH

Feedback inhibition of – does not occur

Answer 7

ADH

Question 8

SIDAH tx

Answer 8

Treat with ADH inhibitor drugs - Demeclocycline

Question 9

Diabetes Insipidus (DI) (2)

Answer 9

Excrete a Dilute Urine

Too little ADH function

Question 10

types of DI (3)

Answer 10

1. Hypothalamic or Central D.I.
2. Nephrogenic D.I.
3. Polydipsic D.I.

Question 11

Hypothalamic or Central D.I. (2)

Answer 11

 Defect in ADH synthesis or release

 Depressed [ADH]plasma

Question 12

Nephrogenic D.I. (3)

Answer 12

 Defect in ADH action
 Failure to maintain hyperosmotic
medullary gradient
 Elevated [ADH]plasma

Question 13

Polydipsic D.I. (1)

Answer 13

 Compulsive water drinking

Question 14

DI Symptoms (3)

Answer 14

Polyuria
Nocturia
Polydipsia

Question 15

Polyuria

 Defined as

Answer 15

greater than 3 liters urine/day

Question 16

Urine volume is determined by 2 factors

Answer 16

– Amount of solute to be excreted (obligatory volume)

– [ADH]plasma

Question 17

3 major mechanisms of polyuria

Answer 17

– Decrease in Na+ reabsorption (Kidney Disease, Diuretics)
– Reduced ADH secretion (D.I.)
– ADH resistance

Question 18

ADH resistance (2)

Answer 18

–Lithium and Tetracylines

–Hypercalcemic Nephrogenic DI

Question 19

Regulation of [Na+]ECF

Mechanisms (4)

Answer 19

*1. Osmoreceptor-ADH 
system.
*2. The thirst mechanism
3. Aldosterone and Ang II
4. Salt Appetite

Question 20

3. Aldosterone and Ang II (2)

Answer 20

Alter Na+ mass but NOT 
concentration
Changes in Na+ mass 
accompanied by volume 
changes (thirst, ADH)

Question 21

Thirst Restores

Answer 21

ECF Volume Losses

Question 22

Hypothalamic thirst
center responds to
signals and initiates

Answer 22

drinking behavior.

Question 23

Thirst increased by (3)

Answer 23

ECF
hyperosmolarity, decreased ECF
volume, decreased MAP.

Question 24

— acts centrally to

increase thirst.

Answer 24

Angiotensin II

Question 25

Stimuli that increase salt appetite are those associated with: (3)

Answer 25

• sodium deficits
• decreased blood volume
• decreased blood pressure associated with circulatory
  insufficiency.

Question 26

Humans function normally at — meq/day.

Answer 26

20

Question 27

Average consumption in US about — meq/day.

Answer 27

200