The document summarizes the cardiovascular system and the heart. It describes the heart's four chambers, with the top two being atria and bottom two being ventricles. The left side pumps oxygen-rich blood through the body via systemic circulation while the right side pumps oxygen-poor blood to the lungs via pulmonary circulation. Valves like the bicuspid, tricuspid, pulmonary and aortic ensure one-directional blood flow and create the lub-dub heart sound.

1. AS Level Biology Cardio Vascular system

2. By the end of this lesson you should know : The function of the heart within the CV system The description of pulmonary and systematic circulation The names of the structures within the heart The functions and location of the semi-lunar and atrio-ventricular valves Outcomes

3. Function The heart is the primary muscle in the body Beats continuously Provides the tissues and cells with oxygen and nutrients Heart is divided in to four chambers

4. The Heart

5. Four Chambers Top two chambers – atria Lower two chambers – ventricles – more muscular than atria as these are the main pumps Muscular wall in the middle – septum dividing the heart sagitally

7. Dual Action Pump Left side of the heart – SYSTEMIC CIRCULATION Circulating oxygen rich blood through the body Right side of the heart – PULMONARY CIRCULATION Circulating oxygen poor blood back to the lungs

9. Major vessels that act as entry and exit points are at the top of the heart To ensure smooth passage of blood through the heart, a number of VALVES exist Valves ensure blood only flows in one direction, and the ‘lub dub’ sound of the heart The ‘lub’ is the sound of the bicuspid and tricuspid valves (atrio-ventricular valves) closing The ‘dub’ sound is the sound of the pulmonary and aortic valves (semi-lunar valves) closing Valves

10. Heart – Cardiac tissue Thick outside tissue – pericardium Thick muscular wall of the heart – myocardium Inner layer of single cells that line the ventricles – endocardium Muscular composition

11. Covering the exterior of the heart are coronary arteries These feed the heart with blood Blockages of these arteries are responsible for many heart problems Cardiovascular diseases – hypertension, angina pectoris and myocardial infarctions (heart attacks) Diseases

13. Place the following terms in correct order to explain the flow of blood through the body, starting with the heart and its path through the body Aorta , left atrium, venae cavae, bicuspid valve, aortic valve, pulmonary valve, pulmonary vein, tricuspid valve, lungs, right ventricle, left ventricle, pulmonary artery Then draw a simple model to illustrate the dual role of the heart, use red lines to show oxygen rich blood and blue lines to show deoxygenated blood Activity

14. Design a poster to illustrate the function and structure of the heart Include the benefits of exercise to the cardio-vascular system on the poster Homework