Circulatory System the Heart
Del diablo, the center of ones universe, let your heart speak for you, all sayings of the heart, but to science the heart is simply a pump that keeps blood moving through a closed circuit of blood vessels. A triangular organ the size of a closed fist. The heart is always pumping blood so naturally it would be of the strongest fibers and muscles of the body. It’s centralling located in the mediastinum. The apex of blunt point of the lower edge of the heart lies on the diaphragm. The two upper chambers of the hear are called atria and the two lower chambers of the heart are called the ventricles. Of the two types of chambers the smaller of the two are the atria, the atria also have smaller walls and less muscular tissue. The atria are often called the receiving chambers because blood enters into the heart through veins into the artia.
Ventricles are the lower or sometimes referred to as the discharging chambers becasue blood exits them into arteries. It is also a muscle contraction that makes the blood movement possible. Caridac muscle tissue making up the wall of each hear chamber is called myocardium. This myocardium is involuntary striated muscle. A thin layer of smooth tiussue lining each heart chamber is called endocardium, if inflamation of the think layer of smooth muscle occurs its called endocarditis. Clotting can occur if there is any rough or abrasive surface adhensions in the endocardium. As stated in a pervous article a blood clot is also known as a thrombus.
The outside lining or covering of the heart is called the pericardium. The inner layer of the pericardium, or covering of the heart is called visceral pericardium. This covering is similar to the outer covering of an apple or the apples skin. The outer layer of the pericardium is loose like a sac allowing the heart to beat and have movement within the mediastinum it’s called the visceral pericardium epicardium.
When the heart muscles contract it’s called systole, this is the medical term for the muscle movement. The opposite movement or relaxation of the heart muscle is called diastole. The two values that separate the atriums from the ventricles are called the Atrioventricular Vales (AV). The two values have separate names the first separates the left atrium and ventricle and is called the mitral value, and the second one separates the atrium and ventricle on the right side and is called the tricuspid valve.
The description of the sounds that a doctor would listen for that the heart makes is called lub dup. The first sound of a heart beat is the closure of the AV Valves as the ventricles contract. The second sound dup of a heart beat is the closing of the semilunar valves when the ventricles relax or called diastole.
