1. The Heart
    Muscular double pump with 2 functions
  2. Pulmonary Circuit
    Right side receives oxygen poor blood from body and pumps into lungs
  3. Systemic Circuit
    Left side receives oxygen rich blood from lungs and pumps it to body
  4. Atria
    2 receiving chambers of the heart
  5. Ventricles
    2 pumping chambers of the heart
  6. Location/Orientation
    • Weighs< 1 pound
    • Thorax, psterior to sternum, superior surface of diaphragm
    • In mediastinum
    • Oblique position
    • Apex= left of mdpnt. and anterior to rest of heart
    • Base is broad posterior surface
  7. Pericardium
    • 3 layered sac that encloses the heart
    • Fibrous pericardium- outer layer (dense CT)
    • Serous preicardium- deeper 2 layers
  8. Parietal Layer of Serous
    Adheres to surface of fibrouf pericardium
  9. Visceral Layer of Serous
    Lies on the heart; is considered part of heart wall
  10. Pericardial Cavity
    Lies between the 2 layers, contains serous fluid
  11. Pericarditis
    Inflammation of the pericardium
  12. Epicardium
    • Superficial layer of heart
    • Serous membrane
  13. Myocardium
    • Cariac Muscle contract
    • Cells arranged in circular/spiral networks called bundles
  14. Endocarium
    Sheet of endothelium resting on thin CT layer, lines chamber and makes up valves
  15. Atria Chambers
    • 2
    • Blooda comes into heart via atria
    • Walls thinner than ventricles
    • Contract and push blood into ventricles simaltaneously
    • Separated by interatrial septum
  16. Ventricle Chambers
    • 2
    • Are thicker (especially left side)
    • Separatd by interventricular septum
  17. Right Atrium
    • Receives systemic oxygen poor blood via three veins, superior/inferior vena cava, and coronary sinus
    • Opens right ventricle via tricuspid valve
  18. Right Auricle
    Flap that protects to the left
  19. 2 Portions of internal atrium
    • Posterior= has smooth walls
    • Anterior= has pectinate muscles
    • Separated by crista terminals= C-shaped ridge, important fro locating where veins enter
  20. Right Ventricle
    • Receives blood from R atrium and pumps it to lungs via pulmonary trunk
    • Forms most of anterior surface of heart
  21. Internal Structures of R ventricle
    Trabeculae carneae- muscle ridges
  22. Papillary muscles
    Cone shaped muscles that project from wall
  23. Chordae Tendineae
    Project superiorly from papillary muscles to valve flaps of tricuspid valve
  24. Pulmonary Semilunar Valve
    Valve between right ventricle and pulmonary trunk
  25. Left Atrium
    • Makes up most of base
    • Receive oxygen rich blood via pulm. veins
    • Auricle is external on anterior side
    • Pectinate muscles line auricle only; rest of inside is smooth
    • Opens into left ventricle via teh mitral valve
  26. Left Ventricle
    • Forms apex of heart, pumps blood systemically
    • Simlilar to right ventricle, with trabeculae carneae, papillary muscles and chordae tendineae
    • Sends blood to body via aortic semilunar valve
  27. Valves of Heart
    To prevent backflow
  28. AV valves- Atrioventricular
    • Between atria ventricles
    • Right side= tricuspid
    • Left side= bicuspid
  29. Semilunar Valves- both have 3 cusps
    • Between ventricle and vessels leaving the heart
    • R side between R ventricle and pulm. artery
    • L side between L ventricle and aorta
  30. Contraction/Realxation
    • Contraction = systole
    • Relaxation= diastole
    • Heartbeat= Atrial contraction then ventricle contraction
    • Lub-Dub made by closing valves
    • Lub= AV in beginning
    • Dup= semilunar valves at end
  31. Fibrous Skeleton
    • Made of dense CT
    • Anchors valve cucps
    • Prevents valves from opening too far
    • Muscle insertion for cardiac bundles
    • Blocks spread of electrical impulses from atria to ventricles
  32. Electrical Conduction
    Measured by EKG- electrocardiogram
  33. SA node
    • Considered pacemaker, 70-80 bpm
    • Located in superior/posterior wall of right atrium
    • Signal that spreads electric impulses across both atria
    • Valves are open
  34. Internodal Pathway
    Some impulses spread through this area ont the way tot he AV node
  35. AV node
    • Located at inferior aspect of interatrial septum
    • Delays impulse so that atria contract first and ventricles finish filing
  36. AV bundle
    • Bundle of His
    • Located in interventricular septum
  37. Left/Right bundle branches
    Branches from atrioventricular bundle, take signal to apex of heart
  38. Purkinje Fibers
    • Approach apex and turn into ventricular walls, located in between endocardium and myocardium
    • Are special cells that maximize signal conduction
  39. Vagus Nerve
    Acts on parasympathetic innervation to SA and AV nodes
  40. Sympathetic System
    Affects SA and AV nodes via cervical/upper thoracic spinal nerves
  41. Atherosclerosis
    Fatty deposits accumulate in body's arteries
  42. Arteriosclerosis
    Hardening/loss of elasticity of the arteries fro any reason
  43. Coronary Artery Disease
    Arteries supplying the heart are blocked or narrowed, chest pain
  44. Myocardial Infarction
    Heart Attack; complete pr prolonged coronary artery blockage
  45. Ischemia
    Heart blood flow is interrupted, but there is no pain involved
  46. Heart Failure
    • Weakening of the heart
    • Congestive heart failure- heart enlarges and pumping efficiency decreases
  47. Conduction System Disorders
    • Arrythmia- variation from normal rhythm of heartbeat
    • Fibrillation- conduction system disturbed
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