Diabetes Mellitus Overview

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following hormones is NOT involved in regulating blood glucose levels?

Glucagon

Aldosterone (correct)

Cortisol

Thyroxine

What is the primary role of insulin in blood glucose regulation?

Stimulates glucose uptake by cells (correct)

Promotes glycogen breakdown in the liver

Increases glucagon release

Enhances glucose production in the kidneys

What is the relationship between blood glucose levels and insulin secretion?

Insulin secretion is independent of blood glucose levels.

Low blood glucose levels stimulate insulin secretion.

Insulin secretion is inversely proportional to blood glucose levels.

High blood glucose levels stimulate insulin secretion. (correct)

What is the precursor of insulin?

Proinsulin (A) Signup and view all the answers

Which of these is NOT a leading cause of death related to diabetes?

Cardiovascular disease (C) Signup and view all the answers

What is the primary function of the GLUT2 transporter in pancreatic beta cells?

Facilitating glucose uptake from the bloodstream (D) Signup and view all the answers

Which of the following processes directly results in depolarization of the pancreatic beta cell membrane?

Increased intracellular potassium concentration (B) Signup and view all the answers

What is the approximate global prevalence of diabetes mellitus in 2019?

463 million (A) Signup and view all the answers

Which glucose transporter is primarily responsible for glucose uptake in skeletal muscle, allowing for glucose storage?

GLUT-4 (D) Signup and view all the answers

Insulin's effect on lipid metabolism includes:

Decreased lipolysis and increased lipogenesis (B) Signup and view all the answers

Which of these glucose transporters is found in pancreatic beta cells and acts as a glucose sensor?

GLUT-2 (B) Signup and view all the answers

What is the primary mechanism by which insulin lowers blood glucose levels?

Promoting glucose uptake into muscle and adipose tissue (B) Signup and view all the answers

Which of the following is NOT a direct effect of insulin on carbohydrate metabolism?

Increased gluconeogenesis in the liver (A) Signup and view all the answers

What is the primary function of GLUT-1?

Glucose transport across the blood-brain barrier (C) Signup and view all the answers

Which of these is NOT a direct consequence of increased intracellular calcium levels in pancreatic beta cells?

Stimulation of insulin synthesis (C) Signup and view all the answers

Insulin's effect on protein metabolism primarily involves:

Increased protein synthesis (A) Signup and view all the answers

What is the primary role of insulin in regulating blood glucose levels?

Facilitating glucose uptake into cells (B) Signup and view all the answers

Which glucose transporter is characterized by its bidirectional transport, allowing for glucose both uptake and release by hepatocytes?

GLUT-2 (B) Signup and view all the answers

Study Notes

Diabetes Mellitus Definition

Chronic disorder marked by impaired glucose metabolism leading to hyperglycemia.
Associated with secondary changes in multiple organs, causing complications.
Caused by insulin deficiency, insulin resistance, or both.

Leading Causes of Diabetes

Non-traumatic lower limb amputation
Adult blindness
End-stage renal disease (ESRD)
Peripheral neuropathy

Diabetes Incidence

Global estimate of 463 million individuals with diabetes in 2019.
Regional variations in the number of cases reported in the 20-79 years age group.
Egypt among the top 10 countries with the highest number of diabetic patients (9 million in 2019).

Hormonal Regulation of Blood Glucose

Decreasing Blood Glucose: Insulin, amylin, GLP-1, GIP
Increasing Blood Glucose: Glucagon, growth hormone, cortisone, catecholamines, thyroxine

Insulin Synthesis

Proinsulin (precursor), cleaved into insulin & C-peptide.
Blood C-peptide level is a marker of endogenous insulin secretion.

Insulin Secretion Stimulation

Increased blood glucose levels stimulate insulin secretion via GLUT2 transporters.
Glucose metabolism generates ATP, blocking ATP-sensitive K channels.
Depolarization opens voltage-gated Ca channels, triggering insulin release via exocytosis.

Glucose Action

CHO (Carbohydrates): Gluconeogenesis & glycogenolysis decrease, glycogenogenesis increases (liver and muscle). Glucose uptake by muscle and fat tissues using glucose transporters.
LIPID: Increased lipogenesis, decreased lipolysis, and ketogenesis.
PROTEIN: A potent anabolic effect mediated by enhanced amino acid uptake.
OTHER: Intracellular K+ shift.

Insulin Action

Insulin binds to its receptor, triggering a cascade of intracellular signaling events.
This cascade includes MAPK, IRS, and PI3K pathways.
Insulin promotes GLUT4 translocation to cell membranes, leading to glucose uptake.
Resultant glucose metabolism promotes protein, lipid, and glycogen synthesis.

Glucose Transporters

GLUT-1: High affinity for glucose, found in blood-brain barrier, RBCs, CNS and cornea, placenta and fetal tissue. Insulin independent.
GLUT-2: High capacity, low affinity glucose transporter, bidirectional, found in kidneys and small intestine/hepatic cells, insulin independent.
GLUT-3: High affinity for glucose, found in many human cells, blood brain barrier, placenta etc. Insulin independent.
GLUT-4: Key role in regulating glucose homeostasis, insulin dependent glucose uptake., located skeletal muscle and heart muscle.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers key aspects of diabetes mellitus, including definitions, causes, incidence, hormonal regulation of blood glucose, and insulin synthesis. It highlights the complications associated with the disorder and provides statistics on the global prevalence of diabetes. Test your knowledge on this critical health issue.