Lab 3  1A Pulmonary valve is the most anterior
 LAB 3

3 The AV node is a right atrial structure that is situated to the right of the membranous septum near the ostium of the coronary sinus.
4A Ventricular dilatation of any cause id the most common causr of mitral regurgitation. The heart section is from a patient with dilated cardiomyopathy. Any cause of ventricular dilatation can cause poor opposition of the atrioventricular valves.

4B Regurgitation.

4C Papillary muscle infarction/rupture, myocardial infarct, left ventricle aneurysm, chordal elongation and rupture, leaflet redundancy, annular dilatation, leaflet perforation.

4D Acute insufficiency - dilatation - pulmonary edema;chronic insufficiency - dilatation and hypertrophy - decreased cardiac output then pulmonary edema, and decreased cardiac output signs and symptoms- heart failure.

5A Stenotic and calcified.

5B The valve is stenotic due to commissure fusion, leaflet fibrosis and calcification.

5C The left atrium increases in size with dilatation and the atrium may also hypertrophy. The left ventricle remains normal size. The right atrium and right ventricular also dilate and hypertrophy due to right sided heart failure.

6A The specimens are age-related degenerative changes, congenitally bicuspid aortic valve and rheumatic valve disease.

6B Two categories- (1) root / ascending aorta pathology and (2) valve pathology

Aortic root dilatation caused by aortitis, aneurysm of aorta, aortic dissection and aortitis with syphilus; valve disease with rheumatic changes, infective endocarditis, and bicuspid aortic valve.

6C Left atrium - hypertrophy and dilatation.

Left ventricle - hypertrophy and dilatation. right atrium /right ventricle - hypertrophy and dilatation.