Diabetes

Question 1

This diabetes disorder is commonly referred to as tasteless.

Answer 1

diabetes insipidus

Question 2

This diabetes disorder is commonly referred to as sweet.

Answer 2

Diabetes mellitus

Question 3

This diabetes disorder involves the proteins that regulate plasma and urine osmolarity.

Answer 3

diabetes insipidus

Question 4

This diabetes disorder involves insulin production and/or sensitivity.

Answer 4

diabetes mellitus

Question 5

Diabetes insipidus involves a deficiency in this hormone that is released from the posterior pituitary.

Answer 5

Arginine-vasopressin/anti-diuretic hormone

Question 6

What is the fxn of AVP [Arginine vasopressin]?

Answer 6

Acts on collecting ducts in the kidney to stimulate expression of a water channel called Aquaporin 2
-permits passive transport of water into cells, concentrating urine & diluting plasma [holding water in the body]

Question 7

True/False: When present in large amounts, AVP has diuretic activity.

Answer 7

True

Question 8

What is the main physiologic stimulus for AVP secretion?

Answer 8

plasma osmolarity

Question 9

What is osmolarity?

Answer 9

a measure of the concentration of solutes which depends on the number of particles in solution & not their molecular weight

Question 10

What are the units for osmolarity?

Answer 10

particles per liter

Question 11

A 300mM solution of MgCl2 is iso-osmolar with what concentration of a NaCl solution?

Answer 11

3 particles of MgCl2
2 particles of NaCl

300 x 3/2 = 450mM

Question 12

True/False: Fewer particles = lower osmolarity

Answer 12

False: fewer particles = higher osmolarity

Question 13

What is the normal contribution of glucose to plasma osmolarity?

Answer 13

6mOsmoles

Question 14

What are the units for plasma osmolarity?

Answer 14

mOsmoles/liter

Question 15

What are the consequences of AVP deficiency?

Answer 15

No H2O resorption via apical side of principal cell; decreased urine osmolarity; increased volume of water lost from body; ultimately diabetes insipidus

Question 16

True/False: Diabetes insipidus patients urinate alot.

Answer 16

True

Question 17

How many liters per day of fluid do diabetes insipidus patients urinate as opposed to the 1 liter per day for healthy patients?

Answer 17

24 liters

Question 18

What is cAMP’s role?

Answer 18

stimulate translocation of vesicles containing water channel, aquaporin 2

Question 19

AVP acts on what receptor in the collecting tubule?

Answer 19

V2 receptor

Question 20

In diabetes insipidus, plasma osmolarity goes [up/down] while urine osmolarity goes [up/down].

Answer 20

plasma osmolarity goes up

urine osmolarity goes down

Question 21

The mortality associated with diabetes insipidus in adults is….

Answer 21

rare as long as they have free access to water

Question 22

What are the two etiologies of Diabetes Insipidus?

Answer 22

Deficiencies in AVP secretion

Deficiencies in AVP action

Question 23

What are the two types of Diabetes Insipidus that result from deficiencies in AVP secretion?

Answer 23

Cranial DI

Gestational DI

Question 24

What specifically causes cranial DI?

Answer 24

due to abnormal hypothalamic or pituitary development; genetic mutation in AVP gene, cell loss, abnormal AVP processing

Question 25

What specifically causes gestational DI?

Answer 25

increased AVP degradation by an aminopeptidase produced by placenta

Question 26

What type of diabetes insipidus is caused by a deficiency in AVP action?

Answer 26

Nephrogenic DI

Question 27

What specifically causes Nephrogenic DI?

Answer 27

genetic, caused by drug exposure [aminoglycosides, methoxyflurane, cisplatin, rifampin, foscarnet, lithium, clozapine]
-genetic form usually a mutation in the V2 AVP receptor or aquaporin 2 channel in distal nephron

Question 28

AVP secretion is typically stimulated at what plasma osmolarity?

Answer 28

280mOsmol/L

Question 29

What are the two general disorders associated with diabetes?

Answer 29

• Diabetes Insipidus

- Diabetes Mellitus