1. Chapter 20 The Heart

2. Introduction  _______________________ (efferent vessels)- carry blood away from heart  _______________ (afferent vessels)- carry blood to the heart  __________________________- thin-walled vessels that connect smallest arteries and veins  Exchange vessels- nutrients, dissolved gases, waste products  Heart beats approx. 100,000 times/day  Pumps approx. ___________________ liters of blood/day

3. Chambers of Heart  Right _________________- receives blood from body  Right _____________________- pumps blood to lungs  Left __________________- blood from lungs  Left ________________________- blood to body

4. Location of Heart  Located near anterior chest wall, posterior to ___________________  ________________-posterior to sternum at 3 rd costal cartilage  ________________-tip of heart; 5 th intercostal space  Approx. 5 inches from base to apex  _______________________- area b/t pleural cavities  Contains:  Great vessels- arteries and veins linked to heart  Thymus  Esophagus  Trachea

5. Pericardium  Lining of pericardial cavity-space b/t parietal and visceral surfaces  Lined by _____________________________________  Visceral pericardium- epicardium; covers and adheres to outer surface of heart  Parietal pericardium- lines inner surface of pericardial sac (surrounds heart)  ________________________________-consists of network of collagen fibers that stabilize position of heart  Pericardial cavity contains ______________ ml of pericardial fluid  Acts as a lubricant; reduces friction  ___________________________  Commonly causes inc. in production of pericardial fluid  Cardiac tamponade- fluid restricts movement of heart

6. Superficial Anatomy of Heart  _________________- thin muscular walls and are highly expandable  When not filled w/ blood it deflates and becomes a lumpy, wrinkled flap- atrial appendage/ auricle  Coronary ________________- deep groove that marks the border b/t atria and ventricles  Anterior and posterior interventricular sulcus – shallower depressions that mark the boundary b/t left and right ventricles  Sulci contain arteries and veins that carry blood to and from cardiac muscle

7. 3 Layers of Heart Wall  _________________________  the visceral pericardium  covers outer surface of heart  __________________________  muscular wall of heart  Forms both atria and ventricles  Contains cardiac muscle tissue, blood vessels, and nerves  __________________________  Inner surface of heart

8. Cardiac Muscle Tissue  Characteristics that distinguish them from skeletal muscle  Small size  Single, centrally located ___________________  Branching interconnections b/t cells  Presence of ___________________________ discs

9. Internal Anatomy  Interatrial _________________________- separates atria  _______________________________ septum- separates ventricles  _______________________________ (AV) valves- extend into openings b/t atria and ventricles  Permit blood flow in only one direction

10. Right Atrium  Receives blood from body through superior and inferior vena cava  Superior vena cava- delivers blood from head, neck, upper limbs and chest  Opens into posterior and superior portion of right atrium  Inferior vena cava- delivers blood from rest of trunk, the viscera, and lower limbs  Opens into posterior and inferior portion of right atrium  Cardiac ______________________- return blood to large, thin walled vein called coronary sinus that opens into right atrium  Opening lies near posterior edge of interatrial septum  _____________________________________-an opening that connects the atria of the fetal heart from 5 th week until birth  Closes at birth  Becomes ____________________________-shallow depression

11. Right Ventricle  Right atrioventicular (AV) valve/ tricuspid- 3 flaps/cusps through which blood flows from RA into RV  Edge of each cusp is attached to chordae tendinae  Closes when ________ contracts  __________________________- muscular ridges inside ventricles  Pulmonary _________________________ valve- 3 cusps through which blood flows from RV to pulmonary trunk  Blood then flows to left and right pulmonary arteries

12. Left Atrium  Receives blood from 2 left and right ______________________ veins  Also known as an ____________________  Left atrioventricular (AV)/ bicuspid valve- b/t left atrium and left ventricle  2 cusps  Also called _____________________ valve

13. Left Ventricle  Larger than the RV; ___________________ walls  ____________________ valve- b/t left ventricle and ascending aorta  Blood then flows through aortic arch and into descending aorta

14. Heart Valves  ____________________________ valves  Prevent backflow from ventricles to atria when ventricles are contracting  When ventricles are relaxes, chordae tendineae are _____________  When ventricles, blood moving back swings the cusps together  _______________________________- backflow

15. Semilunar Valves  Pulmonary and aortic valves  Prevent backflow of blood from ______________________ trunk and ________________

16. Connective Tissues of Heart  Each cardiac muscle cell is wrapped in a strong ______________  Adjacent cells are tied together by fibrous “struts”  Those fibers are interwoven into sheets that separate superficial and deep muscle layers  Functions:  Provide physical support for cardiac muscle fibers, blood vessels, and nerves of myocardium  Help distribute forces of ________________________  Add strength and prevent overexpansion of heart  Provide _______________________ that helps return the heart to its original size and shape after contraction

17. Blood Supply to Heart  ___________________________ circulation- supplies blood to muscle tissue of heart  Includes:  Coronary arteries  Coronary veins

18. Coronary Arteries  Originate at base of ascending aorta at aortic __________________  ______ here is highest  Each time the LV contracts, forces blood into aorta; stretches walls; __________________ BP  When LV relaxes, pressure decreases; walls of aorta recoil- elastic _____________________  Ensures a continuous flow of blood

19. Right Coronary Artery  Follows coronary ___________________ around the heart  Supplies blood to:  _________________________  Portions of both ventricles  Portions of conducting system of heart  Inferior to RA, RCA leads to one or more marginal arteries  Extend across ___________________________  RCA also supplies posterior interventricular artery  Runs toward ___________________  Supplies blood to interventricular septum and portions of ventricles

20. Left Coronary Artery  Supplies blood to:  ___________________________________  LA  Interventricular _________________________  Branches into __________________________ artery  Curves to left around coronary sulcus and eventually meets RCA  Also branches into anterior interventricular artery  Swings around pulmonary trunk and runs along surface within anterior interventricular sulcus  Supplies small tributaries that connect w/ posterior interventricular artery called arterial ______________________  Helps keep blood supply constant

21. Cardiac Veins  ____________________ cardiac vein- begins on anterior surface of ventricles  Drains blood from region supplied by anterior interventricular artery  Empties into coronary sinus- opens into RA  Veins that empty into great cardiac vein or coronary __________________:  Posterior cardiac vein- drains area served by circumflex artery  ______________ cardiac vein- posterior interventricular artery  __________________ cardiac vein- receives blood from posterior surfaces of RA and RV  Anterior cardiac veins- drain anterior surface of RV  Empties directly into RA