The Cardiovascular System What are the features of the Human Circulatory System?

Learning Intention Describe the function of the circulatory system& name the 3 main components of this system. Describe the difference between pulmonary and systemic circuits. State the purpose and structure of the heart.

Structure The Circulatory System has 3 main parts. THE HEART : Main pump of the system. BLOOD : Liquid connective tissue containing blood cells in suspension. BLOOD VESSELS : the tubes through which the blood flows to and from the lungs to body cells.

The Human Circulatory System has 2 circuits PULMONARY CIRCUIT SYSTEMIC CIRCUIT Is a short loop. Carries blood between your heart and lungs. At the lungs, O2 diffuses through the alveoli and attaches to RBCs and CO2 is released from blood and expired through the lungs. Oxygenated blood returns to the heart and is pumped to the systemic circuit. Carries oxygenated blood too all body cells. Blood flows through smaller and smaller vessels until it reaches each cell. At the cells, the blood releases O2 and picks up CO2 and other wastes. Deoxygenated blood then returns to the heart where it joins the pulmonary circuit to be oxygenated. Video showing systemic and pulmonary circuits.

Side Walk Chalk and Talk Using chalk grab some friends move outside and draw the heart circuits showing blood flow LARGE SCALE. Use your heart diagram handout as a guide or find an image on line! When complete run through your diagram when your arms are up your represent OXYGENATED BLOOD. When they are down your represent DEOXYGENATD BLOOD.

The Heart PURPOSE The heart is a pump – its job is to move blood through a circulatory system. It is about the size of your fist LOCATION Located beneath the sternum, just left of centre of the chest cavity.

The Heart Structure The heart is a hollow shaped organ with thick walls of cardiac muscle. It is surrounded by a loose-fitting double walled sac called the PERICARDIUM. THE PERICARDIUM Covers and protects the heart Anchors the heart to the diaphragm and breastbone

2 Sides & 4 Chambers The heart has 2 sides – separated by a thick muscle called the septum. The separate sides of the heart keep oxygenated blood separate from deoxygenated blood. Each side of the heart has two chambers. Upper chambers are the Atria (atrium singular) Lower chambers are the Ventricles ATRIA Receive blood or collect blood Are smaller than ventricles Have thin walls VENTRICLES Pump blood out of the heart Are much larger than atria and have thicker wallls as they work to pump blood. Click on 3D heart diagram – video of the internal structure of the heart explains valves really well.

The Human Heart Interactive Log on to the following website : www.smm.org/heart Complete the task sheet

The Heart Valves The heart contains valves that function to keep blood moving in one direction thereby preventing backflow. Name and Locate the key Valves on the diagram.

Identifying Valves Complete the task sheet

What have you learnt? Describe the function of the circulatory system & name the 3 main components of this system. Describe the difference between pulmonary and systemic circuits. State the purpose and structure of the heart.

Heart Dissection