Circulatory System The circulatory system is the body’s highway system for transporting materials. Delivers oxygen to cells Take carbon dioxide away from cells Delivers food to cells so they can grow and make energy. Carries hormones to organs Carries antibodies places that need healing Delivers heat where needed
Blood Carry O2 and CO2 (primarily contains Hemoglobin) Red Blood Cells aka “Erythrocytes”: Carry O2 and CO2 (primarily contains Hemoglobin) Made in bone marrow Old ones destroyed in Liver and Spleen White Blood Cells aka “Leukocytes”: Immune System…different types Platelets: Needed for blood clotting Plasma: liquid made of the following: Water – solvent to carry other things. Absorbs heat Salts – osmotic balance, pH buffering, regulates membrane permeability Plasma proteins – albumin (osmotic balance and pH buffering), fibrinogen (clotting), globulins (antibodies, and lipid transport) Blood
Pathways of Circulation Arteries (carry blood away from heart) Arterioles (enters tissues/organs) Capillaries (one cell thick) Tissues and organs Venules Veins (carry blood back to heart)
Your Heart It is the size of your fist. Contains 4 chambers 2 atria 2 ventricles Your Heart
Blood's Path Through the Heart Superior vena cava/Inferior vena cava Right Atrium Right Ventricle Pulmonary Artery Lungs Pulmonary veins (4 of them) Left Atrium Left Ventricle Aorta Body
What is it. Pressure the blood exerts. against the inner walls of the What is it? Pressure the blood exerts against the inner walls of the blood vessels. Blood vessels are not rigid…they are elastic (they can expand and contract) During each beat of the heart, the pressure rises and falls. It is how the blood continues to circulate between heartbeats. Blood Pressure How is it measured? Two arterial pressures are measured. Systolic pressure – the pressure in the arteries at the peak of ventricular contraction (top number) Diastolic pressure – the pressure when the ventricles are relaxing. (bottom number)
What effects blood pressure? Increase/decrease blood volume Increase/decrease the amount of friction the blood encounters as it flows through the arteries. Vasoconstriction (narrowing of the blood pressure) controlled by the brain. Temperature Chemicals Diet Age, Race, Mood, Physical activity, Posture