The Heart Size of your fist Lies in the centre of the thoracic cavity A pump (two pumps actually) 4 Chambers 4 Valves 4 Vessels

The Heart Diagram Handout tory-System-01.htm

1. Oxygenated blood from the lungs travels to the heart via the pulmonary veins and enters the left atrium. 2. Oxygenated blood flows through the left atrioventricular valve into the left ventricle. 3. The muscular left ventricle pumps the oxygenated blood through the aortic valve into the aorta. 4. Oxygenated blood flows to the systemic circuit. 5. Deoxygenated blood from the systemic circuit flows through the vena cava (superior & inferior) into the right atrium. 6. Deoxygenated blood flows through the right atrioventicular valve into the right ventrical. 7. The right ventricle pumps the deoxygenated blood through the pulmonary valve into the pulmonary arteries where it travels to the lungs.

Heart Beat “Lub” –Atrioventricular valves close –Pressure builds up in the ventricles until the pulmonary and aortic valves open –Blood is pumped into the pulmonary artery and the aorta “Dub” –Pulmonary and aortic valves close –Atrioventricular valves open and ventricles fill with blood

Control of heart beat Specialized tissue in the right atrium called the “pacemaker” (sinoatrial node) Sends an electrical impulse across the heart –The atria to contract –The atrioventricular node is stimulated –Ventricles contract Series of electrical impulses maintain a rhythmic beat

Blood Pressure The force your heart uses to push blood through the blood vessels Systolic: heart contracts and blood is forced through the vessels (higher pressure, 120mmHg) Diastolic: Heart relaxes (lower pressure, 70mmHg) Written as 120/70 Anything between over is healthy

Schwartzenager Heart surgury Heart surgury (less intense): ant/ ant/

1. _________________ blood from the _______ travels to the heart via the _________ __________ and enters the _____________________ 2. __________________ blood flows through the _________ _____________________ into the _______________ 3. The muscular _____________ ___________ pumps oxygenated blood through the ____________ ______________ into the __________________ 4. __________________ blood flows to the ______________________________ 5. __________________ blood from the _______________ ____________ flows through the ___________________ (superior & inferior) into the ______________________ 6. __________________ blood flows through the _________ ______________________ into the ________________ 7. The ________________________ pumps deoxygenated blood through the __________________________ into the __________________________ where it travels to the _____________ Blood Flow Through the Heart