The Heart - Circulatory System
The Heart’s wall is made up of three layers, the outer lay is the Pericardium. The Pericardium is a double-layered membrane that encases the heart like a sac. The outer layer of the Pericardium surrounds the roots of the heart’s major blood vessels and attaches to the Spinal Column, Diaphragm and other parts of the body using ligaments. The inner layer of the Pericardium is attached to the Heart, the main role of the Pericardium is to hold the Heart in position.
The middle layer is the Myocardium, this makes up most of the bulk of the Heart tissue and is responsible for the pumping action.
The final layer is the Endocardium, this is a smooth layer of connective tissue that forms a smooth lining for all four chambers of the heart.
Cardiac Output
Cardiac output is the amount of blood pumped by the heart during a one minute period. Cardiac output shows us the functional capacity of the cardiovascular...
Heart Rate
The average heart rate for a sedentary person is between 60 and 80 beats per minute, with the national average in the UK considered to be 72 beats per...
Stroke Volume
Stroke volume will increase approximately twice its resting level when exercising. Unlike the heart rate, stroke volume does not increase linearly with work...
Blood Pressure
The barorceptors monitor blood pressure and provide information to the cardiovascular control unit in the brain, from here the pressure is compared to the...
Blood Flow
During exercise blood flow is redistributed to the working muscle tissue to maintain performance. As the blood is redistributed, the cardiac output...
The Heart
The action of the Heart is that of a double action pump that pumps simultaneously. Blood enters the heart through the superior and inferior vena cava where it then enters the right atrium . Blood then passes through the tricuspid valve into the right ventricle. Finally it enters into the pulmonary arteries for distribution to the lungs.
Now that the blood is in the lungs the CO2 is removed and O2 is replenished into the blood. The blood will now re-enter the heart via the left atrium, then pass through the bicuspid (mitral) valve before going into the left ventricle and being forced into the aorta and out of the heart.