lab 2

• The pericardial sac surrounds the heart.
• The fibrous pericardium is composed of dense CT and anchors the heart.
• The serous pericardium is double layered and forms a sack around the heart.
• The visceral pericardium adheres to the surface of the heart (inner layer of pericardium).
• The parietal pericardium is behind the fibrous.
• The coronary sulcus divides the external surface of the heart b/t the atria and ventricles.
• The anterior + posterior interventricular sulci divide the left and right ventricles.
• The fibrous skeleton provides insulation + support.
• The coronary circulation functions to deliver blood to the myocardium.
• The left side of the heart has oxygenated blood.
• The right side of the heart has deoxygenated blood.
• Superior vena cava to right atrium to tricuspid valve to right ventricle to pulmonary semilunar valve to pulmonary artery to pulmonary vein to left atrium to bicuspid valve to left ventricle to aortic semilunar valve to aorta.
• Cardiac muscle has striations and multiple nuclei.
• Intercalated discs are special membranes and contain GAP junctions that allow cardiac muscle cells to share ions and contract as a unit.
• Cold temperature decreases heart rate.
• Warm temperature increases heart rate.
• Epinephrine increases heart rate.
• Pilocarpine decreases heart rate.
• Atropine increases heart rate.
• Digitalis decreases heart rate.
• Calcium increases heart rate.
• Sodium causes unsteady heart rate.
• Potassium causes unsteady heart rate.