WBR1000
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Histology |
| Sub Category | SubCategory::Endocrine |
| Prompt | [[Prompt::A scientist injects rats with insulin antibodies to induce experimental diabetes.
Shown below is an image depicting the localization of the insulin antibody by immunofluorescent microscopy. Shown in red are the insulin antibodies and shown in blue are green unspecific anti-mouse secondary antibody staining mostly the intercellular matrix. To which of the following cells does the area in red corresponds to? |
| Answer A | AnswerA::Alpha cella |
| Answer A Explanation | [[AnswerAExp::Alpha cells produce glucagon. Alpha cells form 15–20% of the total number of cells of the islets of langerhans.]] |
| Answer B | AnswerB::Beta cells |
| Answer B Explanation | [[AnswerBExp::Beta cells produce insulin and amylin. Beta cells form 65–80% of the total number of cells of the islets of langerhans.]] |
| Answer C | AnswerC::Delta cells |
| Answer C Explanation | [[AnswerCExp::Delta cells produce somatostatin. Delta cells form 3–10% of the total number of cells of the islets of langerhans.]] |
| Answer D | AnswerD::Gamma cells |
| Answer D Explanation | [[AnswerDExp::Gamma cells, or PP cells, produce pancreatic polypeptide. Gamma cells form 3–5% of the total number of cells of the islets of langerhans.]] |
| Answer E | AnswerE::Epsilon cells |
| Answer E Explanation | [[AnswerEExp::Epsilon cells produce ghrelin. Epsilon cells form <1% of the total number of cells of the islets of langerhans.]] |
| Right Answer | RightAnswer::B |
| Explanation | [[Explanation::Hormones produced in the islets of Langerhans are secreted directly into the blood flow by (at least) five types of cells. In rat islets, endocrine cell subsets are distributed as follows: - Alpha cells producing glucagon (15–20% of total islet cells) Educational objective: The islets of langerhans are formed by different types of cells. Beta cells occupy the center of the islet of langerhans and produce insulin. Reference:
First aid for USMLE step 1, (2013). Page 287. |
| Approved | Approved::No |
| Keyword | WBRKeyword::Beta cells, WBRKeyword::insulin |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
