WBR0884: Difference between revisions

Jump to navigation Jump to search
(Created page with "{{WBRQuestion |QuestionAuthor={{Rim}} |ExamType=USMLE Step 1 |MainCategory=Embryology |SubCategory=Musculoskeletal/Rheumatology |MainCategory=Embryology |SubCategory=Musculosk...")
 
No edit summary
Line 8: Line 8:
|MainCategory=Embryology
|MainCategory=Embryology
|SubCategory=Musculoskeletal/Rheumatology
|SubCategory=Musculoskeletal/Rheumatology
|MainCategory=Embryology
|MainCategory=Embryology
|MainCategory=Embryology
|MainCategory=Embryology
|MainCategory=Embryology
Line 20: Line 21:
|MainCategory=Embryology
|MainCategory=Embryology
|SubCategory=Musculoskeletal/Rheumatology
|SubCategory=Musculoskeletal/Rheumatology
|Prompt=A 4 year old boy is brought to the pediatrics clinic for his regular well baby check-up. The child seems to be developing well and has not missed any of his milestones so far. His physical exam was unremarkable except for a persistant soft spot on the child's skull suspicious for delayed closure of the fontanelles. Which of the following tissues share the same embryologic origin with the bones responsible for fontanelle closure?  
|Prompt=A 4 year old boy is brought to the pediatrics clinic for his regular well baby check-up. The child seems to be developing well and has not missed any of his milestones so far. His physical exam was unremarkable except for a persistant soft spot on the child's skull suspicious for delayed closure of the fontanelles. Which of the following tissues share the same embryologic origin with the bones responsible for fontanelle closure?
|Explanation=The bones of the skull, unlike the rest of the skeletal system, are derived from neural crest cells. Other bones are generally derived from the mesodermal layer. Other derivatives of neural crest cells  include:
|Explanation=The bones of the skull, unlike the rest of the skeletal system, are derived from neural crest cells. Other bones are generally derived from the mesodermal layer. Other derivatives of neural crest cells  include:
<li> Chromaffin cells of the adrenal medulla
<li> Chromaffin cells of the adrenal medulla
Line 33: Line 34:
<li> Celiac ganglion
<li> Celiac ganglion


Educational objective: Both the arachnoid mater and the bones of the skull are derived from the neural crest cells.
Reference:<br>
Crane JF, Trainor PA. Neural crest stem and progenitor cells. Annu Rev Cell Dev Biol. 2006;22(1):267-86.
|AnswerA=Arachnoid mater
|AnswerA=Arachnoid mater
|AnswerAExp=The arachnoid mater is derived from neural crest cells similar to the bones of the skull.
|AnswerAExp=The arachnoid mater is derived from neural crest cells similar to the bones of the skull.
Line 49: Line 44:
|AnswerE=Anterior pituitary
|AnswerE=Anterior pituitary
|AnswerEExp=The anterior pituitary is derived from surface ectoderm.
|AnswerEExp=The anterior pituitary is derived from surface ectoderm.
|EducationalObjectives=Both the arachnoid mater and the bones of the skull are derived from the neural crest cells.
|References=First Aid 2014 page 553 <br> Crane JF, Trainor PA. Neural crest stem and progenitor cells. Annu Rev Cell Dev Biol. 2006;22(1):267-86.
|RightAnswer=A
|RightAnswer=A
|WBRKeyword=Embryologic derviatives, neural crest cells, bones of the skull, arachnoid mater
|WBRKeyword=Embryologic derviatives, neural crest cells, bones of the skull, arachnoid mater
|Approved=No
|Approved=No
}}
}}

Revision as of 16:47, 6 September 2014

 
Author [[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Embryology
Sub Category SubCategory::Musculoskeletal/Rheumatology
Prompt [[Prompt::A 4 year old boy is brought to the pediatrics clinic for his regular well baby check-up. The child seems to be developing well and has not missed any of his milestones so far. His physical exam was unremarkable except for a persistant soft spot on the child's skull suspicious for delayed closure of the fontanelles. Which of the following tissues share the same embryologic origin with the bones responsible for fontanelle closure?]]
Answer A AnswerA::Arachnoid mater
Answer A Explanation AnswerAExp::The arachnoid mater is derived from neural crest cells similar to the bones of the skull.
Answer B AnswerB::Skeletal muscles
Answer B Explanation AnswerBExp::Skeletal muscles are derived from mesoderm unlike the bones of the skull which are dervied from neural crest cells.
Answer C AnswerC::Kidneys
Answer C Explanation AnswerCExp::the kidneys are also derived from mesoderm.
Answer D AnswerD::Retina
Answer D Explanation AnswerDExp::The retina is derived from neuroectoderm.
Answer E AnswerE::Anterior pituitary
Answer E Explanation AnswerEExp::The anterior pituitary is derived from surface ectoderm.
Right Answer RightAnswer::A
Explanation [[Explanation::The bones of the skull, unlike the rest of the skeletal system, are derived from neural crest cells. Other bones are generally derived from the mesodermal layer. Other derivatives of neural crest cells include:
  • Chromaffin cells of the adrenal medulla
  • Parafollicular C cells of the thyroid
  • Schwann cells
  • Cranial nerves>
  • Majority of ANS
  • Odontoblasts
  • Aorticopulmonart septum
  • Pia and arachnoid mater
  • Melanocytes
  • Celiac ganglion
    Educational Objective: Both the arachnoid mater and the bones of the skull are derived from the neural crest cells.
    References: First Aid 2014 page 553
    Crane JF, Trainor PA. Neural crest stem and progenitor cells. Annu Rev Cell Dev Biol. 2006;22(1):267-86.]]
  • Approved Approved::No
    Keyword WBRKeyword::Embryologic derviatives, WBRKeyword::neural crest cells, WBRKeyword::bones of the skull, WBRKeyword::arachnoid mater
    Linked Question Linked::
    Order in Linked Questions LinkedOrder::