Cardiovascular System: Anatomy And Physiology
Cardiovascular System Anatomy & Physiology
The heart is the pump responsible for maintaining adequate circulation of oxygenated blood around the vascular network of the body. It is a four-chamber pump, with the right side receiving deoxygenated blood from the body at low presure and pumping it to the lungs (the pulmonary circulation) and the left side receiving oxygenated blood from the lungs and pumping it at high pressure around the body (the systemic circulation).
The myocardium (cardiac muscle) is a specialised form of muscle, consisting of individual cells joined by electrical connections. The contraction of each cell is produced by a rise in intracellular calcium concentration leading to spontaneous depolarisation, and as each cell …show more content…
1. These cells generate a rhythmical depolarisation, which then spreads out over the atria to the atrio-ventricular node. 2. The atria then contract, pushing blood into the ventricles. 3. The electrical conduction passes via the Atrio-ventricular node to the bundle of His, which divides into right and left branches and then spreads out from the base of the ventricles across the myocardium. 4. This leads to a 'bottom-up' contraction of the ventricles, forcing blood up and out into the pulmonary artery (right) and aorta (left). 5. The atria then re-fill as the myocardium relaxes. | …show more content…
* The Q wave represents depolarisation at the bundle of His; again, this is small as there is little muscle there. * The R wave represents the main spread of depolarisation, from the inside out, through the base of the ventricles. This involves large ammounts of muscle so the deflection is large. * The S wave shows the subsequent depolarisation of the rest of the ventricles upwards from the base of the ventricles. * The T wave represents repolarisation of the myocardium after systole is complete. This is a relatively slow process- hence the smooth curved deflection.
The heart is the pump responsible for maintaining adequate circulation of oxygenated blood around the vascular network of the body. It is a four-chamber pump, with the right side receiving deoxygenated blood from the body at low presure and pumping it to the lungs (the pulmonary circulation) and the left side receiving oxygenated blood from the lungs and pumping it at high pressure around the body (the systemic circulation).
The myocardium (cardiac muscle) is a specialised form of muscle, consisting of individual cells joined by electrical connections. The contraction of each cell is produced by a rise in intracellular calcium concentration leading to spontaneous depolarisation, and as each cell …show more content…
1. These cells generate a rhythmical depolarisation, which then spreads out over the atria to the atrio-ventricular node. 2. The atria then contract, pushing blood into the ventricles. 3. The electrical conduction passes via the Atrio-ventricular node to the bundle of His, which divides into right and left branches and then spreads out from the base of the ventricles across the myocardium. 4. This leads to a 'bottom-up' contraction of the ventricles, forcing blood up and out into the pulmonary artery (right) and aorta (left). 5. The atria then re-fill as the myocardium relaxes. | …show more content…
* The Q wave represents depolarisation at the bundle of His; again, this is small as there is little muscle there. * The R wave represents the main spread of depolarisation, from the inside out, through the base of the ventricles. This involves large ammounts of muscle so the deflection is large. * The S wave shows the subsequent depolarisation of the rest of the ventricles upwards from the base of the ventricles. * The T wave represents repolarisation of the myocardium after systole is complete. This is a relatively slow process- hence the smooth curved deflection.