1. DAY 1 – CHAPTER 15 Cardiovas cular System

2. Overview Vascular System blood circulates inside closed transport systems

3. Anatomy of the Heart General  Size : approximately the size of a person’s fist  Location : in the mediastinum - the cavity in the center of the chest Coverings: Pericardium  Double layered sac  Contains roughly half an ounce of pericardial fluid to reduce the friction of the beating heart  Parietal layer : fibrous membrane; outer layer  Visceral layer : serous membrane; also called the epicardium; attached to myocardium

4. Heart Wall Myocardium : heart muscle; thicker on left side of the heart Endocardium : lining of heart chambers; endothelial tissue continuous with the lining of the blood vessels

5. Chambers of the Heart Atria  2 upper chambers of heart; thin walls, smooth inner surface  Responsible for receiving blood  Right atrium receives deoxygenated (oxygen poor) blood from the body through the superior and inferior vena cava  Left atrium receives oxygenated (oxygen rich) blood from the lungs through the pulmonary veins Ventricles  2 lower chambers of the heart; thicker walls, irregular inner surface  Contain papillary muscles and chordae tendineae (prevent heart valves from turning inside out when ventricles contract)  Left wall 3x as thick as right wall; forms apex of heart  Responsible for pumping blood away from the heart  Right ventricle sends deoxygenated blood to the lungs via the pulmonary arteries  Left ventricle sends oxygenated blood to all parts of the body via the aorta

6. Chambers of the Heart (ctd.) Accessory Structures  Septum : muscular wall dividing the heart into right and left halves  Heart valves: prevents the backflow of blood  Papillary muscles  Chordae tendineae

7. Great Vessels Superior and inferior vena cava : receive deoxygenated blood from all parts of the body Coronary sinus : returns deoxygenated blood from the myocardium to the right atrium Pulmonary arteries : carry deoxygenated blood to the lungs from the right ventricle Pulmonary veins : carry oxygenated blood to the left atrium from the lungs Aorta : carries oxygenated blood to distribute to all parts of the body

8. Blood Vessels Types of Blood Vessels :  Arteries  Arterioles  Capillary beds  Venules  Veins

9. Anatomy of Blood Vessels Three coats ( tunics ): 1. Tunica intima : endothelium lines the interior of vessels; decreases friction as blood flows 2. Tunica media : smooth muscle & elastic tissue (dilates & constricts vessels) 3. Tunica externa : fibrous connective tissue on outside supports and protects vessels

11. Arteries Carry blood AWAY from the heart All BUT pulmonary arteries carry oxygenated blood Aorta : largest artery; 1 inch in diameter Arterioles : smallest arteries Coronary arteries : most important; supply blood to the heart muscle  Left and right main coronary artery  Left coronary artery - left anterior descending, left circumflex branch  Right coronary artery - right atrium and right ventricle

12. Veins Carry blood TOWARD the heart All BUT pulmonary veins carry deoxygenated blood Layers much thinner, less elastic Series of internal valves that work against the flow of gravity to prevent reflux Superior and inferior vena cava : largest veins Venules : smallest veins

13. Vericose Veins People stand for long periods of time  inactivity or pressure on veins Blood pools in feet and legs Valves weaken  veins become twisted & dilated Treatment: compression stockings, exercise, laser treatment, surgery

14. Capillaries Tiny, microscopic vessels Walls one cell layer thick Function: to transport and diffuse essential materials to and from the body’s cells and the blood

16. Arteries Capillaries Veins Blood away from heart Thicker walls Withstand high pressure Walls 1-cell thick Exchange gases between blood and tissue cells Blood back to heart Thinner walls Low pressure Large lumen Valves Valves: prevent blood backflow Skeletal muscles enhance venous return

17. Vital Signs Pulse : expansion & recoil of an artery with each beat of left ventricle Pressure points (eg. carotid artery, radial artery)  Normal resting: 70-76 beats/min

18. DAY 2 Cardiovascular System

19. Vital Signs Blood pressure : pressure of blood on inner walls of blood vessels Systolic presure : peak of ventricular contraction Diastolic pressure : ventricles relaxed  Written: Systolic/Diastolic  Normal: (120 mm Hg)/(70 mm Hg) or 120/70

20. Measuring Blood Pressure

21. Using a sphygmomanometer Wrap cuff around upper arm Place stethoscope on brachial artery Inflate cuff to 180 mm Hg Slowly release air  listen for whooshing sounds in brachial artery ( Korotkoff sounds )  Systolic: when sounds begin to appear  Diastolic: when sounds disappear

22. Homeostatic Imbalances Hypertension : high blood pressure (>140/90) Circulatory shock : acute hypotension  Blood loss Atherosclerosis – artery walls thicken due to fatty deposits (plaques)

23. Stent vs. Bypass Surgery

24. Congestive Heart Failure Progressive weakening of heart Low heart efficiency  circulation inadequate to meet tissue needs Caused by :  Coronary atherosclerosis  Persistent high blood pressure  Multiple heart attacks – scar tissue