1. Four chambers: left atrium, left ventricle, right atrium, right ventricle
2. There is a mitral valve between the left atrium and the ventricle; there is a tricuspid valve between the right atrium and the ventricle.
3. There is the aortic valve between the left ventricle and the aorta; there is the pulmonic valve between the right ventricle and the pulmonary artery.
4. The heart wall is divided into 3 layers, from outside to inside: epicardium, muscular layer, and endocardium.
5. The pericardial cavity contains a small amount of serous fluid for lubrication.
6. The coronary arteries are blood vessels that nourish the heart. They originate from the root of the aorta and have two left and right branches.
7. The left coronary artery is divided into the anterior descending branch and the circumflex branch, and is mainly responsible for the blood supply to the myocardium of the left atrium, left ventricular anterior wall, lateral wall and the first 2/3 of the interventricular septum.
8. The right coronary artery mainly supplies the right atrium, right ventricle, posterior wall of the left ventricle, the myocardium in the posterior 1/3 of the interventricular septum, the sinoatrial node, the atrioventricular junction, etc.
9. The cardiac conduction system includes: sinoatrial node, internodal bundle, atrioventricular node, His node, left and right bundle branches and their branches, and Purkinje fibers, which are responsible for the formation and conduction of normal cardiac impulses.
10. The sequence of excitation conduction in the heart: sinoatrial node → atrial muscle → atrioventricular bundle and left and right bundle branches → Purkinje fibers → ventricular muscle
11. In normal people, ventricular depolarization begins in the middle of the interventricular septum and depolarizes from left to right; then the left and right ventricular free walls depolarize from the endocardium to the epicardium.
12. The base of the left ventricle and the cone of the pulmonary artery of the right ventricle are the last parts of the ventricle to depolarize.
13. The physiological characteristics of cardiomyocytes include autonomy, conductivity, excitability, and contractility.