Cardiovascular System aka Circulatory System Section 2.1

Cardiovascular System Cardio- means heart Vascular- means blood vessels Aka Circulatory System because its job is to circulate blood throughout the body. Blood carries many materials including: Nutrients from food Oxygen from the lungs Wastes from cells Hormones (chemical messages)

The Heart Heart- main organ of the cardiovascular system made mostly of cardiac muscle tissue Right side pumps oxygen poor blood to the lungs (left side in pictures) Left side pumps oxygen rich blood to the body (right side in pictures) 4 chambers: atrium = upper, ventricle = lower One-way valves separate the chambers so blood can’t flow backwards

Heart Structure Atrium- receives blood Ventricle- sends blood (thick muscle) Arteries- carry blood away from the heart Veins- carry blood towards the heart Valves- prevent backwards flow of blood

Blood Vessels Arteries- bring blood away from heart Thick, muscular walls to help pump and withstand pressure. Typically carry oxygenated blood. EXCEPTION: Pulmonary artery carries deoxygenated blood away from heart to the lungs.

Blood Vessels cont. Capillaries- exchange materials with cells Extremely thin-walled blood vessels. Exchange O2 and nutrients for CO2 and wastes.

Blood Vessels cont. Veins- bring blood towards the heart One-way valves to prevent blood from flowing backwards Typically carry deoxygenated blood. EXCEPTION: Pulmonary vein carries oxygenated blood towards the heart from the lungs.

Circulation Loops Systemic Circulation- blood flow between the heart and the body. Purpose: to deliver O2 and nutrients and pick up wastes from body cells Left ventricle (larger to pump to entire body) Pulmonary Circulation- blood flow between the heart and the lungs. Purpose: to replenish O2 and drop off CO2 at lungs. Right ventricle

Heart Health Cardiovascular problems affect your entire body. Atherosclerosis (narrowing of blood vessels) Hypertension (high blood pressure) Heart attack & stroke- blood flow to heart or brain is blocked Causes: smoking, high cholesterol, stress, physical inactivity, heredity Eat healthy and get plenty of exercise to keep cardiovascular system healthy