1. The Circulatory System Consists of the heart, the blood vessels, and the lungs

2. Functions of the Circulatory System 1.Transports O 2 & nutrients (sugars, amino acids) to body cells 2.Transports hormones throughout body 3.Carries wastes away from cells 4.Works with the immune system to protect body against disease causing pathogens

3. Parts of the Blood 1. Plasma – fluid portion – transports all of the material 2. Red Blood Cells: (RBC’s) a.Transports oxygen to body cells b.Removes waste from body cells 3. White blood cells: (WBC’s) a.Protect against infection; fight parasites & attack bacteria 4. Platelets: cell fragments a.Stick to broken blood vessels b.Helps body heal wounds by forming clots Plasma Platelets WBC’s RBC’s

4. Blood Vessels 1. Arteries: large vessels; carry blood away from heart a.All arteries carry O 2 rich blood 2. Veins: large blood vessels; return blood to heart a.Have valves to keep blood from flowing backwards 3. Capillaries – smallest blood vessels a.Bring nutrients & O 2 to cells b.Absorb CO 2 & wastes from body cells

5. The Heart 1. Heart – muscular organ a. 4 chambers b. Pumps blood from heart to lungs & back to heart, to tissues throughout body 2. Septum: muscular wall in heart a. Separates right side from left side b. Keeps O 2 poor & O 2 rich blood from mixing

6. The Heart 3. Atria – 2 upper chambers a. Receive blood from body (right) or lungs (left) & pump blood into ventricles 4. Ventricles – 2 lower chambers a. Pump blood out of heart to lungs (right) or aorta (left)

7. a.Transports O 2 poor blood to lungs and O 2 rich blood back to the heart b. Blood travels from right side of heart to lungs c. Blood picks up O 2 & releases CO 2 in lungs d. O 2 rich blood returned to left side of heart How the Heart Works: Pulmonary Circulation

8. a. O 2 rich blood exits left ventricle & enters aorta b. O 2 rich blood travels through arteries then capillaries c. O 2 diffuses out of capillaries & into cells; blood picks up CO 2 & other wastes d. Veins return O 2 poor blood to right side of heart (right atria) How the Heart Works: Systemic Circulation

9. Vena cava  Right atrium  right ventricle  pulmonary artery  lungs  pulmonary vein  left atrium  left ventricle  aorta Pathway: Pulmonary Circulation

10. Left ventricle  aorta  arteries  capillaries  veins  vena cava  right artium Pathway: Systemic Circulation

11. Circulatory System Diseases 1. Leukemia: bone marrow produces abnormal WBCs. At first, leukemia cells function normally. In time, there are too many & they crowd out normal WBCs, RBCs & platelets. 2. Hemophilia: an inherited disorder. Afflicted persons cannot produce clotting factors, which causes people w/ hemophilia to bleed for longer periods of time than people whose produce clotting factors. The main problem w/ hemophilia is internal bleeding, mainly into muscles & joints.

12. Circulatory System Diseases 3. Arteriosclerosis: arteries become hard & brittle because calcium is deposited in their walls. Vessels become thickened & lose elasticity. Blood pressure increases & blood clots may form 4. Stroke: blood clot blocks artery or a blood vessel breaks, interrupting blood flow to an area of the brain. Brain cells begin to die & abilities controlled by that area of the brain are lost.

13. Circulatory System Diseases 5. High Blood Pressure: hypertension; BP 140 / 90 or higher for an extended period of time. Damage to heart & blood vessels; makes it harder for to pump the heart. Can lead to stroke or heart attack