Posterior Pit Hormones

Question 1

Function of Oxytocin (2)

Answer 1

1. milk letdown

2. uterine contraction

Question 2

ADH (AVP) works on _____ cells of the the distal tubule to ________.

Answer 2

• principle cells

- increase water absorption

Question 3

ADH induces _______ of _______ to protect against severe volume depletion

Answer 3

• contraction

- vascular smooth mm

Question 4

ADH is released in response to _____

Answer 4

• increased serum osmolality

Question 5

ADH increases expression of _____ on the ____side of principle cells.

Answer 5

• aquaporin 2

- luminal

Question 6

ADH ____ urine flow and ____ urine osmolality

Answer 6

• decreases

- increases

Question 7

In diabetes insipidus, individuals are unable to _______ normally and excrete _______. This causes an _____.

Answer 7

• concentrate urine
• a large volume of urine
• increase in thirst

Question 8

Primary or Central Neurogenic Diabetes Insipidus is due to ____.

Answer 8

• the failure of the posterior pituitary to secrete ADH

Question 9

Symptoms of Central Neurogenic DI (4)

Answer 9

• Low levels of circulating ADH
• decreased permeability of collecting ducts
• dilute urine / concentrated serum
• no effect of water restriciton

Question 10

In Secondary Nephrogenic DI, the _____ is normal, there is a defect in the _____.

Answer 10

• posterior pituitary

- Target Tissue (V2 receptor or aquaporin 2)

Question 11

Symptoms of Secondary Nephrogenic DI

Answer 11

• High serum ADH

- dilute urine/ concentrated serum

Question 12

Common cause of secondary (nephrogenic) DI ?

Answer 12

Lithium toxicity - Li interferes with V2 receptors

Question 13

DI urine characteristics

Answer 13

• hypotonic/ dilute

- tasteless

Question 14

Diabetes Mellitus urine Characteristics

Answer 14

• hypertonic

- sweet

Question 15

DI is diagnosed by a _____ stimulus followed by the _____.

Answer 15

• dehydration

- inability to concentrate urine

Question 16

Changes for Neurogenic DI:

• Plasma Osmolality
• Plasma Osmolality
• Urine Osmolality
• Plasma ADH
• Water deprivation; urine osmolality
• water deprivation; plasma ADH
• urine osmolality after ADH administration

Answer 16

• normal/high
• low
• low
• no change
• no change
• increase

Question 17

Changes for Nephrogenic DI:

• Plasma Osmolality
• Plasma Osmolality
• Urine Osmolality
• Plasma ADH
• Water deprivation; urine osmolality
• water deprivation; plasma ADH
• urine osmolality after ADH administration

Answer 17

• normal/high
• low
• normal/high
• no change
• increase
• no change

Question 18

SIADH stands for

Answer 18

Syndrome of Inappropriate ADH

Question 19

In SIADH, ADH secretion is not linked to _____-

Answer 19

Normal regulatory mechanisms

Question 20

Primary Hyponatremia in SIADH is do to:

Answer 20

increased water resorption

Question 21

Secondary Hyponatremia in SIADH is do to:

Answer 21

ANP (atrial natriuretic peptide) triggered by increased blood volume (water follows salt)

Question 22

Lab values of SIADH 3

Answer 22

• low Na
• Low serum osmolality
• high urine osmolality

Question 23

SIADH is corrected upon ____

Answer 23

• water restriction