Diabetes Education Certification Diabetes Pathophysiology & Types 3

Question 1

Which hormone secreted by alpha cells DIRECTLY opposes insulin action and is abnormally elevated in both Type 1 and Type 2 diabetes?

Accepted Answer

Glucagon

Answer

Glucagon secreted by pancreatic alpha cells stimulates hepatic glucose production and is inappropriately elevated in both types of diabetes, worsening hyperglycemia.

Question 2

The 'incretin effect' is significantly reduced in Type 2 diabetes. Which incretins are primarily involved?

Accepted Answer

GLP-1 and GIP

Answer

GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) are the two main incretins whose reduced effect contributes to impaired postprandial insulin secretion in Type 2 diabetes.

Question 3

Ketosis in Type 1 diabetes occurs primarily because:

Accepted Answer

Absence of insulin disinhibits lipolysis, flooding the liver with free fatty acids

Answer

Without insulin, adipose tissue lipolysis is uninhibited, releasing excessive free fatty acids that the liver converts to ketone bodies (acetoacetate, beta-hydroxybutyrate).

Question 4

Which condition is characterized by severe insulin resistance due to mutations in the insulin receptor gene?

Accepted Answer

Donohue syndrome (Leprechaunism)

Answer

Donohue syndrome (Leprechaunism) is caused by homozygous loss-of-function mutations in the insulin receptor gene (INSR), resulting in extreme insulin resistance from birth.

Question 5

The GLUT4 glucose transporter is unique compared to other glucose transporters because it:

Accepted Answer

Requires insulin signaling to translocate to the cell membrane

Answer

GLUT4 is insulin-responsive; insulin signaling causes GLUT4 vesicles to translocate from intracellular pools to the plasma membrane, enabling glucose uptake in muscle and adipose tissue.

Diabetes Practice Test

Diabetes Practice Test

Diabetes Education Certification Diabetes Pathophysiology & Types 3