WBR0601
| Author | [[PageAuthor::Ayokunle Olubaniyi, M.B,B.S [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Physiology |
| Sub Category | SubCategory::Endocrine |
| Prompt | [[Prompt::A 58 year old woman with recently diagnosed type 2 diabetes mellitus comes to the clinic for a follow-up on her blood glucose. Her fasting blood sugar today is 4.5 mmol/l and she is doing well on diet and exercise. You decided to further educate her on the physiology of insulin.
Which of the following requires insulin for glucose uptake?]] |
| Answer A | AnswerA::Brain cells |
| Answer A Explanation | AnswerAExp::Brain cells take up glucose through the activity of GLUT-1 (Glucose Transporter-1) |
| Answer B | AnswerB::Liver cells |
| Answer B Explanation | AnswerBExp::Liver cells make use of GLUT-2 |
| Answer C | AnswerC::Skeletal muscle |
| Answer C Explanation | AnswerCExp::Skeletal muscle contains GLUT-4 but they require the action of insulin for glucose uptake |
| Answer D | AnswerD::Kidney |
| Answer D Explanation | AnswerDExp::Kidneys contain GLUT-4 for uptake of glucose |
| Answer E | AnswerE::Red blood cells |
| Answer E Explanation | AnswerEExp::Red blood cells contain GLUT-4 for glucose uptake |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::Insulin is an anabolic hormone produced in the beta cells of the pancreas. It is involved in numerous processes in the body such as fatty acid synthesis, protein synthesis, and glucose metabolism. In glucose metabolism, insulin is needed in the transport of glucose into cells in skeletal muscle and adipose tissue. Some organs e.g., brain, RBCs, intestine, cornea, kidney, liver, and beta islet cells do not require insulin action for glucose uptake. Glucose transporters are required for uptake of glucose into many organs. There are 4 subtypes:
GLUT-1 – RBCs, brain cells GLUT-2 - Renal tubular cells, small intestinal epithelial cells, liver cells and pancreatic beta cells GLUT-3 – Neurons, placenta GLUT-4 – Skeletal muscle, adipose tissue Educational Objective: Insulin aids in glucose uptake in skeletal muscles and adipose tissues. Reference: First Aid Text, 2012; pg 315 |
| Approved | Approved::No |
| Keyword | WBRKeyword::Insulin, WBRKeyword::glucose transporters, WBRKeyword::glucose uptake |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |