Circulatory system

The Hearts function The heart’s function is to pump blood to all parts of the body in order to provide oxygen and nutrients.

Blood pathway Deoxygenated blood enters the blood in the right atrium from the superior and inferior vena cava. This blood is pushed down into the right ventricle and is kept from flowing back by the tricuspid valve. From here the ventricle pushes the blood to the lungs through the pulmonary artery in order to be oxygenated. The pulmonary semilunar valve keeps blood from running back into the right ventricle. After blood has been oxygenated the blood travels back into the heart through the pulmonary vein to the pulmonary vein to the left atrium.

Blood pathway(continued) When the atrium contracts blood moves to the mitral valve into the left ventricle. Finally, the oxygenated blood moves through the aortic valve to the aorta where it is transported to the rest of your body.

Blood vessels Arteries-carry blood away from the heart. Veins-carry blood to the heart. Capillaries- tiny blood vessels that connect arteries to veins and move blood from the arteries to veins. Capillaries allow tissues in body to receive oxygen and nutrients.

Structure helps it function Arteries are strong & flexible in order to deal with the high blood pressures Veins are larger & have thinner walls to move more blood to the heart Capillaries are 1 cell thick in order to move wastes, nutrients and other materials through the capillaries.

Blood Composition? Blood has 4 components 1.Plasma - 55% 2.Platelets - <1% 3.WBC’S - <1% 4.RBC’S -45%

Blood components (continued) Plasma – water, minerals, nutrients, sugar and proteins, also carries waste Platelets- clotting cuts WBC’S- fights off pathogens RBC’S- deliver’s oxygen

What factor’s affect blood flow? Blood pressure is the force by which blood pushes against the wall of an artery. Blood pressure is systolic/diastolic healthy=120/80 Systolic- L ventricle contracts Diastolic L ventricle relaxes

What factor’s affect blood flow?(continued) Diet, stress, and, smoking can all cause high blood pressure. Eating fatty foods can cause blockages in vessels, and smoking can cause the narrowing of blood vessel.