{"id":"2054","type":{"id":"30","name":"Pathophysiologic Disorders","urlId":"pathophysiologic-disorder","subtypes":[],"schema":"http:\/\/schema.org\/Article","numTerms":0},"subtype":{"id":"149","name":"Respiratory Pathologies","urlId":"respiratory-pathologies"},"urlId":"flow-volume-loops","role":"term","course":{"id":"38","urlId":"pathology","name":"Clinical Pathology"},"children":[],"name":"Flow-Volume Loops","demo":0,"description":"\u003E ### **Flow-Volume Loops**\n\nFlow-Volume Loops plot inspiratory and expiratory flow against volume during maximally forced inspiration and expiration.  \n\nThe normal inspiratory portion is convex and symmetrical; the expiratory portion usually shows a quick rise to peak flow rate, followed by a linear fall in flow until residual volume is reached. \n\nIn obstructive lung diseases, the loop shifts to the left, because lung volumes are higher than normal (air is trapped); \nFEV1 decreases more than FVC, so FEV1\/FVC is reduced.\n\nIn restrictive lung diseases, the loop shifts to the right, because lung volumes are lower than normal (lung compliance is reduced). \n\nFEV1 and FVC decrease proportionally, so FEV1\/FVC is normal (or elevated). \n\nBe aware that these loops also provide information about the type of obstruction (variable intrathoracic, variable extrathoracic, or fixed).  \n\n# For References, please see full tutorial on Respiratory Pathology Overview","keywords":[],"images":[{"id":"4469","url":"term\/images\/combined-graph-flow-volume-loops-4469.png","title":"Combined Graph Flow-Volume Loops","demo":false}],"radiographs":[],"curricula":[{"id":"38","level":"graduate","category":"individual","urlId":"pathology","name":"Clinical Pathology","subjectGroups":[{"id":"465","name":"Pulmonology","urlId":"respiratory-pathologies","subjects":[{"id":"2881","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1}]},{"id":"2","level":"graduate","category":"individual","urlId":"gross-anatomy","name":"Gross Anatomy","subjectGroups":[{"id":"56","name":"Respiratory System","urlId":"respiratory-system","subjects":[{"id":"7250","urlId":"respiratory-tract","name":"Respiratory Tract","tutorials":[{"id":"965","urlId":"lungs","title":"Lungs and Pleura","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1}]},{"id":"3","level":"graduate","category":"individual","urlId":"physiology","name":"Physiology","subjectGroups":[{"id":"74","name":"Respiratory","urlId":"respiratory","subjects":[{"id":"270","urlId":"respiratory-mechanics","name":"Respiratory Mechanics","tutorials":[{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]},{"id":"1544","urlId":"overview","name":"Overview","tutorials":[{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]},{"id":"2882","urlId":"pathology-concepts","name":"Respiratory Pathology","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":4}]},{"id":"11","level":"undergraduate","category":"individual","urlId":"anatomy-physiology","name":"Advanced Anatomy \u0026 Physiology","subjectGroups":[{"id":"119","name":"Respiratory","urlId":"respiratory","subjects":[{"id":"476","urlId":"physiology","name":"Physiology","tutorials":[{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3}]},{"id":"16","level":"undergraduate","category":"individual","urlId":"general-biology","name":"General Biology","subjectGroups":[{"id":"266","name":"The Cardiorespiratory and Immune Systems","urlId":"the-cardiorespiratory-immune-systems","subjects":[{"id":"967","urlId":"the-respiratory-system","name":"The Respiratory System","tutorials":[{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3}]},{"id":"17","level":"secondary","category":"individual","urlId":"ap-biology","name":"AP Biology","subjectGroups":[{"id":"249","name":"Cardiorespiratory and Immune Systems","urlId":"cardiorespiratory-immune-systems","subjects":[{"id":"920","urlId":"the-respiratory-system","name":"The Respiratory System","tutorials":[{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3}]},{"id":"26","level":"graduate","category":"individual","urlId":"respiratory-system","name":"Respiratory System","subjectGroups":[{"id":"440","name":"Anatomy \u0026 Histology","urlId":"anatomy","subjects":[{"id":"1663","urlId":"lower-respiratory-tract","name":"Lower Respiratory Tract","tutorials":[{"id":"965","urlId":"lungs","title":"Lungs and Pleura","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1},{"id":"441","name":"Physiology","urlId":"physiology","subjects":[{"id":"1657","urlId":"overview","name":"Overview","tutorials":[{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]},{"id":"1658","urlId":"respiratory-mechanics","name":"Respiratory Mechanics ","tutorials":[{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3},{"id":"809","name":"Pathology","urlId":"pathology","subjects":[{"id":"5351","urlId":"pathology-overview","name":"Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1}]},{"id":"37","level":"graduate","category":"individual","urlId":"pharmacology","name":"Clinical Pharmacology","subjectGroups":[{"id":"808","name":"Respiratory System","urlId":"respiratory-system","subjects":[{"id":"2934","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1}]},{"id":"39","level":"secondary","category":"individual","urlId":"anatomy-physiology-fundamentals","name":"Anatomy \u0026 Physiology Fundamentals","subjectGroups":[{"id":"411","name":"Respiratory","urlId":"respiratory","subjects":[{"id":"1613","urlId":"physiology","name":"Physiology","tutorials":[{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3}]},{"id":"43","level":"undergraduate","category":"test-prep","urlId":"mcat-biology-biochemistry","name":"MCAT Biology \u0026 Biochemistry","subjectGroups":[{"id":"1298","name":"Respiratory System","urlId":"respiratory-system","subjects":[{"id":"5415","urlId":"respiratory-physiology","name":"Respiratory Physiology","tutorials":[{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3}]},{"id":"51","level":"graduate","category":"test-prep","urlId":"usmle-comlex-step-2","name":"USMLE \/ COMLEX - Step 2","subjectGroups":[{"id":"1154","name":"Pulmonology","urlId":"respiratory-pathologies","subjects":[{"id":"4557","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1}]},{"id":"52","level":"graduate","category":"test-prep","urlId":"usmle-comlex-step-3","name":"USMLE \/ COMLEX - Step 3","subjectGroups":[{"id":"1173","name":"Pulmonology","urlId":"respiratory-pathologies","subjects":[{"id":"4672","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1}]},{"id":"63","level":"postgraduate","category":"individual","urlId":"pance-high-yield","name":"Physician Assistant (PA)","subjectGroups":[{"id":"907","name":"Respiratory System (10% of exam)","urlId":"respiratory-system","subjects":[{"id":"3483","urlId":"anatomical-overviews","name":"Anatomy \u0026 Physiology Reviews","tutorials":[{"id":"965","urlId":"lungs","title":"Lungs and Pleura","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]},{"id":"3487","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3}]},{"id":"86","level":"graduate","category":"test-prep","urlId":"usmle-comlex-step-1","name":"USMLE \/ COMLEX - Step 1","subjectGroups":[{"id":"1135","name":"Respiratory System","urlId":"respiratory-pathologies","subjects":[{"id":"4442","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]},{"id":"4903","urlId":"respiratory-p","name":"Respiratory Anatomy \u0026 Physiology","tutorials":[{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":4}]},{"id":"92","level":"postgraduate","category":"individual","urlId":"nurse-practitioner","name":"Nurse Practitioner (NP)","subjectGroups":[{"id":"1251","name":"Respiratory System","urlId":"respiratory-system","subjects":[{"id":"5168","urlId":"anatomical-overviews","name":"Anatomy \u0026 Physiology Reviews","tutorials":[{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"965","urlId":"lungs","title":"Lungs and Pleura","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]},{"id":"5171","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":4}]},{"id":"93","level":"graduate","category":"individual","urlId":"clinical-medicine-medical-students","name":"Clinical Medicine","subjectGroups":[{"id":"1323","name":"Pulmonology","urlId":"respiratory-pathologies","subjects":[{"id":"5525","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1}]},{"id":"97","level":"graduate","category":"individual","urlId":"internal-medicine-residency","name":"Internal Medicine Residency","subjectGroups":[{"id":"1371","name":"Pulmonology","urlId":"respiratory-pathologies","subjects":[{"id":"5906","urlId":"respiratory-pathology-overview","name":"Respiratory Pathology Overview","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":1}]},{"id":"105","level":"graduate","category":"individual","urlId":"anatomy-physiology-pearls","name":"Anatomy \u0026 Physiology Pearls","subjectGroups":[{"id":"1456","name":"Respiratory System","urlId":"respiratory-system","subjects":[{"id":"6380","urlId":"physiology","name":"Respiratory Physiology","tutorials":[{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":2}]},{"id":"106","level":"graduate","category":"individual","urlId":"ems-pearls","name":"EMS Pearls","subjectGroups":[{"id":"1465","name":"Respiratory System","urlId":"respiratory-system","subjects":[{"id":"6397","urlId":"physiology","name":"Respiratory Physiology","tutorials":[{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]},{"id":"6416","urlId":"pulmonology","name":"Pulmonology","tutorials":[{"id":"1645","urlId":"respiratory-pathology-overview","title":"Respiratory Pathology Overview","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3}]},{"id":"107","level":"undergraduate","category":"individual","urlId":"anatomy-physiology-for-nursing","name":"Anatomy \u0026 Physiology Fundamentals for Nursing","subjectGroups":[{"id":"1480","name":"Respiratory System","urlId":"respiratory-system","subjects":[{"id":"6476","urlId":"physiology","name":"Physiology","tutorials":[{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":2}]},{"id":"109","level":"graduate","category":"individual","urlId":"medical-prematriculation-program","name":"Medical Prematriculation Program","subjectGroups":[{"id":"1519","name":"Respiratory Physiology","urlId":"respiratory-physiology","subjects":[{"id":"6600","urlId":"verview","name":"Overview","tutorials":[{"id":"1282","urlId":"overview-of-respiratory-structures-and-functions","title":"Introduction to Respiratory Physiology","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]},{"id":"6601","urlId":"respiratory-mechanics","name":"Respiratory Mechanics","tutorials":[{"id":"951","urlId":"fundamental-lung-volume-and-capacity","title":"Lung Volume and Capacity","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0},{"id":"956","urlId":"fundamental-respiratory-mechanics","title":"Respiratory Mechanics","hasQuizQuestions":0,"hasNotes":0,"hasStarterImage":0,"hasSlides":0}]}],"numTutorials":3}]}],"favorite":0,"numAnnotations":0}