Heart and circulatory system
oTransport system of the body
Heart - anatomy
nBlood as the media
nOxygen / CO2
nNutrients to cells
nWaste removal
oHeart acts as the pump
nPositive displacement pump
nHeart muscles – drive
nRhythmic contraction and expansion of muscles controlled by electrical signals
oBlood vessels acts as the pathways – tubular structures
Heart - anatomy
oHas four chambers
nTwo pumping chambers
oFour non return valves
nTwo valves on either side
oRight side pumps through the lungs (pulmonary circulation)
oLeft side pumps through the entire body (systemic circulation)
oLeft heart & its valves are more susceptible to damage, since it works against the entire vascular resistance of systemic circulation
Blood vessels
oArteries carry blood from the heart to various organs
oTransfer of oxygen, carbon dioxide and nutrients occur in the capillary network at various organs
oVeins collect the blood and returns to the heart for pumping again
oBlood flow controlled by the vessel resistances and pressure generated by the heart
Circulatory system - revisited
oThe natural pacemaker of the heart is the Sinoatrial (SA) node
oThe electrical impulse leaves the SA node and travels to the right and left atria, causing them to contract together
oThe electrical impulse subsequently reaches Atrio ventricular Node (AV node) and travels through the Bundle of His where it rapidly spreads using Purkinje Fibers to the muscles of the Right and Left Ventricle, causing them to contract at the same time
Working of heart
oThe natural pacemaker of the heart is the Sinoatrial (SA) node
oThe electrical impulse leaves the SA node and travels to the right and left atria, causing them to contract together
oThe electrical impulse subsequently reaches Atrio ventricular Node (AV node) and travels through the Bundle of His where it rapidly spreads using Purkinje Fibers to the muscles of the Right and Left Ventricle, causing them to contract at the same time
