The Circulatory System

1. The Circulatory System The Cardiovascular System: Transportation System of the Body

2. Objectives • Students will learn: • Structures of the heart • Vessels in the cardiovascular system • Flow of blood through the cardiovascular system

3. Parts of the Circulatory System • The heart – the pump that pushes the blood around the vascular system • The Blood vessels – arteries, capillaries and veins; serve as the highway for the blood to travel • Blood – the tissue that flows through the vessels to every cell in the body delivering oxygen and nutrients to the body

4. The Heart • Size of a closed fist • Lies behind the sternum • Located between the lungs in the chest cavity • The pump of the body

5. Layers of the heart • Endocardium – smooth muscles that lines the heart • Myocardium – middle layer of muscle • Pericardium – double-layered membrane that covers the heart; • Pericardial fluid – lubricating fluid that fills the space between the 2 layers of pericardium to reduce friction and damage

6. Anatomy of the Heart

7. Anatomy of the Heart • Septum – muscle wall that separates right and left sides of heart • 4 chambers – • Right Atrium • Right Ventricle • Left Atrium • Left Ventricle

8. Cardiac Cycle • Heart works as a double pump • Systolic – heart is at work • Diastolic – heart is at rest

9. Conduction • Electrical impulse begins at the Sinoatrial (SA) Node, the pace maker of the hear, spreads over the atria to the Atrioventricular (AV) node. The impulse is sent through the Bundle of His, a group of nerve fibers in the septum. The Bundle of His divides into the Left Bundle Branch and the Right Bundle Branch carrying the impulse through the ventricles and futher dividing into the Purkinje fibers.

10. Blood Vessels • Arteries – carry blood away from the heart • Carry oxygen rich blood (red blood) • Aorta – arteries – arterioles

11. Blood Vessels • Veins • Return blood from the tissue cells to the heart • Carry carbon dioxide rich blood and waste products • Venuoles – veins – Superior and Inferior Vena Cava

12. Blood Vessels

13. Blood • Called a tissue because it contains so many different cells • 4-6 quarts of blood in average adult • Continuously circulates • Transports Oxygen and nutrients to the cells • Carries away Carbon Dioxide and waste from the cells

14. Blood Parts • Erythrocytes – RBC - Red Blood Cells-responsible for carrying oxygen/CO2 • Leukocytes – WBC - White Blood Cells- Responsible for fighting infection • Thrombocytes – Platelets- responsible for blood clottng • Plasma – Liquid that suspends the cells

15. Red blood cells Produced in the bone marrow Disk shaped w/ thin inner layer Covered with Hemoglobin – works like velcro to hold oxygen until the blood reaches the tissue cells then it releases the oxygen and picks up carbon dioxide Blood is red because of the oxygen stuck to the Hemoglobin

16. Red Blood Cells Normal Erythrocytes Sickle Cell Anemia Erythrocytes

17. Leukocytes - WBC White blood cells in a field of red cells (Top left) Monocyte, (top centre) basophil, (top right) platelets, (bottom left) two neutrophils, (bottom right) lymphocyte and eosinophil, respectively. Fight infection

18. Thrombocytesplatelets Fragments or pieces of cells Responsible for blood clotting - Secrete chemical that causes vessel to spasm and narrow - Rlease Fibrinogen which forms a gel-like web that catches erythrocytes, platlets and plasma to form a clot

19. Blood clotting

20. Plasma Suspends all the solid parts of the blood ( RBC, WBC, and platlets) 90 % water Affected by the amount of fluid intake daily.

21. Circulation of the Blood • http://www.mydr.com.au/default.asp?article=3178mydr.com

22. Questions