WBR0865: Difference between revisions

Jump to navigation Jump to search
VisualWikitext
(Created page with "{{WBRQuestion |QuestionAuthor={{Rim}} |ExamType=USMLE Step 1 |MainCategory=Physiology |SubCategory=Pulmonology |MainCategory=Physiology |SubCategory=Pulmonology |MainCategory=...")
 
No edit summary
Line 1: Line 1:
{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{Rim}}
|QuestionAuthor={{SSK}} (Reviewed by Serge Korjian)
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Physiology
|MainCategory=Physiology
Line 8: Line 8:
|MainCategory=Physiology
|MainCategory=Physiology
|SubCategory=Pulmonology
|SubCategory=Pulmonology
|MainCategory=Physiology
|MainCategory=Physiology
|MainCategory=Physiology
|MainCategory=Physiology
|MainCategory=Physiology
Line 25: Line 26:
[[Image:WBR0865.png|500px]]
[[Image:WBR0865.png|500px]]
|Explanation=The pulmonary vasculature is peculiar in its response to hypoxia. Where hypoxia typically causes vasodialtion to increase tissue perfusion, alveolar hypoxia in the lungs causes local vasoconstriction. This physiologic mechanism is thought to be an adaptive process that decreases perfusion of the hypoventilated areas and shunts blood towards better perfused alveoli. This mechanism is the basis behind several disease processes including RVH in the context of chronic hypoxia where the latter leads to vasoconstriction and pulmonary hypertension.
|Explanation=The pulmonary vasculature is peculiar in its response to hypoxia. Where hypoxia typically causes vasodialtion to increase tissue perfusion, alveolar hypoxia in the lungs causes local vasoconstriction. This physiologic mechanism is thought to be an adaptive process that decreases perfusion of the hypoventilated areas and shunts blood towards better perfused alveoli. This mechanism is the basis behind several disease processes including RVH in the context of chronic hypoxia where the latter leads to vasoconstriction and pulmonary hypertension.
Learning objective: The pulmonary vasculature reacts to hypoxia by vasoconstriction to shunt blood to better perfused areas on the lung.
Reference:
Moudgil R, Michelakis ED, Archer SL. Hypoxic pulmonary vasoconstriction. J Appl Physiol. 2005;98(1):390-403.
|AnswerA=A
|AnswerA=A
|AnswerAExp=This response represents an exxagerated normal response in tissues. It is usually not seen in physiologic situations.
|AnswerAExp=This response represents an exxagerated normal response in tissues. It is usually not seen in physiologic situations.
Line 43: Line 36:
|AnswerE=E
|AnswerE=E
|AnswerEExp=This represents the typical response of the pulmonary vascular bed to oxygen variation.
|AnswerEExp=This represents the typical response of the pulmonary vascular bed to oxygen variation.
|EducationalObjectives=The pulmonary vasculature reacts to hypoxia by vasoconstriction to shunt blood to better perfused areas on the lung.
|References=Moudgil R, Michelakis ED, Archer SL. Hypoxic pulmonary vasoconstriction. J Appl Physiol. 2005;98(1):390-403.
|RightAnswer=E
|RightAnswer=E
|WBRKeyword=Pulmonary vasculature, hypoxia
|WBRKeyword=Pulmonary vasculature, Hypoxia, vasoconstriction, vasodilation, perfusion, ventilated. ventilation/perfusion ratio
|Approved=No
|Approved=Yes
}}
}}

Revision as of 19:46, 6 March 2015
Author [[PageAuthor::Serge Korjian M.D. (Reviewed by Serge Korjian)]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Physiology
Sub Category SubCategory::Pulmonology
Prompt [[Prompt::An important characteristic of the pulmonary circulation is its ability to adapt to different oxygen concentrations to maintain good exchange and oxygen delivery to tissues. Below is a graph showing the arterial responses of various tissue beds as oxygen concentrations are modified. Which of the presented curves closely resembles the response of the pulmonary vasculature?


]]

Answer A AnswerA::A
Answer A Explanation AnswerAExp::This response represents an exxagerated normal response in tissues. It is usually not seen in physiologic situations.
Answer B AnswerB::B
Answer B Explanation AnswerBExp::This response represents the normal tissue response seen in most vascular beds except in the lung.
Answer C AnswerC::C
Answer C Explanation AnswerCExp::This is not a physiologic response pattern to oxygen variation.
Answer D AnswerD::D
Answer D Explanation AnswerDExp::This is not a physiologic response pattern to oxygen variation.
Answer E AnswerE::E
Answer E Explanation AnswerEExp::This represents the typical response of the pulmonary vascular bed to oxygen variation.
Right Answer RightAnswer::E
Explanation [[Explanation::The pulmonary vasculature is peculiar in its response to hypoxia. Where hypoxia typically causes vasodialtion to increase tissue perfusion, alveolar hypoxia in the lungs causes local vasoconstriction. This physiologic mechanism is thought to be an adaptive process that decreases perfusion of the hypoventilated areas and shunts blood towards better perfused alveoli. This mechanism is the basis behind several disease processes including RVH in the context of chronic hypoxia where the latter leads to vasoconstriction and pulmonary hypertension.

Educational Objective: The pulmonary vasculature reacts to hypoxia by vasoconstriction to shunt blood to better perfused areas on the lung.
References: Moudgil R, Michelakis ED, Archer SL. Hypoxic pulmonary vasoconstriction. J Appl Physiol. 2005;98(1):390-403.]]

Approved Approved::Yes
Keyword WBRKeyword::Pulmonary vasculature, WBRKeyword::Hypoxia, WBRKeyword::vasoconstriction, WBRKeyword::vasodilation, WBRKeyword::perfusion, WBRKeyword::ventilated. ventilation/perfusion ratio
Linked Question Linked::
Order in Linked Questions LinkedOrder::
Retrieved from "https://www.wikidoc.org/index.php?title=WBR0865&oldid=1075737"