Lab 30. Heart Anatomy Cardiac muscle slide • Look at the slide • Sketch and label: striations, intercalated discs, branching points • Answer the questions Dissection • • • • Obtain fresh cow heart Rinse thoroughly to remove clotted blood Place in dissection tray Pick up dissection tools External anatomy Orient so that anterior interventricular sulcus slants diagonally from your upper right to your lower left (see diagram) Peel back pericardium (if present) Locate external features of the heart: • Right atrium, auricle of right atrium, right ventricle, left atrium, auricle of left atrium, left ventricle, pulmonary trunk, aorta, coronary sulcus, posterior interventricular sulcus • Also: Superior and inferior vena cava, right barchiocephalic trunk, left carotid and subclavian arteries, descending aorta Heart Internal anatomy Make a cut on the side of one ventricle, starting in the middle and continuing to the apex. Examine the interior anatomy. If you can’t yet see the valves, you can carefully extend your cut up toward the atrium. After examining inside, repeat this procedure for the other ventricle • Chordae tendinae, left and right AV valves, right and left semilunar valves, papillary muscle, trabeculae carnae Connect your two ventricle cuts to complete a frontal section of the heart. Note interventricular septum Clean Up • • • • Put hearts back in plastic container Throw away gloves, paper towels Place dissection utensils in the sink Rinse dissection mat an place on paper towels to dry • Clean up your area