120 likes | 231 Views
Circulatory System. http://kidshealth.org/PageManager.jsp?lic=1&article_set=59298&cat_id=20607. Circulatory System. Often called the cardiovascular system Consists of the heart, blood vessels, and blood. Functions. Carries needed substances to cells such as glucose and oxygen.
E N D
http://kidshealth.org/PageManager.jsp?lic=1&article_set=59298&cat_id=20607http://kidshealth.org/PageManager.jsp?lic=1&article_set=59298&cat_id=20607
Circulatory System • Often called the cardiovascular system • Consists of the heart, blood vessels, and blood
Functions • Carries needed substances to cells such as glucose and oxygen. • Carries unwanted waste away from cells • Contains cells in blood that fight disease
The Heart • Hollow organ made of cardiac muscle • 2 upper chambers are called atria that receive blood. • 2 lower chambers are called ventricles that pump blood
How the Heart Works • Two phases • Heart muscle relaxes and fills with blood • Heart muscle contracts and pumps blood forward • “Lub-dup”- sound of your heartbeat as valves close when heart is pumped
Kinds of Blood Vessels • Arteries- carries blood away from the heart • Veins-carries blood to the heart • Capillaries-tiny vessels that exchange substances between blood and body cells (usually by diffusion)
Pathway of Blood • Loop One- “Picking up oxygen” • Oxygen poor blood: Heart>lungs>heart • Loop Two- “Dropping off Oxygen” • Oxygen rich blood: Heart>body>heart
Pulse vs. Blood Pressure Pulse Blood pressure • expansion and contraction of arteries • determines number of heartbeats. • force of blood caused by ventricles contracting • measured with a sphygmomanometer
Cardiovascular Disease • Atherosclerosis- occurs when fatty materials such as cholesterol build up in the arteries possibly leading to a heart attack. • Hypertension- occurs when blood pressure is too high causing the heart to work harder.
Maintaining Cardiovascular Health • Exercise regularly • Eat balanced diet low in saturated and trans fats, cholesterol and sodium • Reduce stress • Avoid smoking.