Heart

  1. Closed System
    The blood remains in blood vessels and heart. 
  2. Double System
    • 4 chambers separated between oxygenated and deoxygenated blood.
    • Double Organ: Right side pumps to lungs; Left side pumps to body tissues
  3. Arteries
    • Blood Vessel
    • Carry blood away from the heart
    • Usually carry blood high in oxygen
  4. Veins
    • Blood Vessel
    • Carry blood back toward the heart 
    • Usually carry blood low in oxygen
  5. Pulmonary Circuit
    • Pathways of flow between heart & lungs
    • Includes: Chambers on right side of heart; Pulmonary arteries & veins
    • Transports oxygen-poor blood from the heart to lungs (Pulmonary arteries)
    • Transports oxygen-rich blood from lungs to heart (Pulmonary veins)
  6. Pulmonary Arteries
    • Transport oxygen poor blood from heart to lungs
    • Reduces carbon dioxide and and replenishes oxygen in blood
  7. Pulmonary veins
    Transport oxygen rich blood from lungs to heart
  8. Systemic Circuit
    • Pathway flow between heart & body tissues
    • Includes: Chambers on left side of heart; Systemic arteries & veins
    • Transport oxygen-rich blood from heart to body tissues (Systemic arteries) 
    • Transports oxygen-poor blood from body tissues to heart (Systemic veins)
  9. Systemic Arteries
    Transport oxygen rich blood from heart to body tissues
  10. Systemic Veins
    Transport oxygen-poor blood from body tissues to heart
  11. Location of the heart
    • Mediastinum, 2/3 to Left of midline 
    • Deep to sternum
    • Medial to lungs
    • Superior to Diaphragm
    • Anterior to Esophagus
  12. Right border of Heart
    • Formed by the right atrium and right ventricle
    • Located more anteriorly
  13. Left Border of Heart
    • Formed by Left atrium & left ventricle
    • Located more posteriorly
  14. Superior Border of Heart
    Formed from the ascending aorta, pulmonary trunk, superior vena cava
  15. Inferior Border of Heart
    • Formed by the Right ventricle 
    • Rests on diaphragm
  16. Apex of the Heart
    • Inferior
    • Conical Tip
  17. Base of the Heart
    • Posterior surface 
    • Most made up of Left atrium
  18. Pericardium
    • Encloses Heart & bases of Great Vessels
    • Surrounds, protects & confines heart
    • Composed of two main parts: Fibrous Pericardium & Serous Pericardium
  19. Fibrous Pericardium
    • Tough, inelastic, dense irregular C.T.
    • Rests on & attaches to diaphragm; Attaches to Great Vessels 
    • Prevents overstretching of heart
    • Anchors heart in mediastinum
    • Superficial layer
  20. Serous Pericardium
    • Thin, double-layered serous membrane
    • Outer Parietal Layer
    • Inner Visceral Layer
    • Contains a Pericardial Cavity
    • Inner Pericardium 
  21. Parietal Layer
    • Outer layer of Serous Pericardium 
    • Its fused to fibrous pericardium
  22. Visceral Layer
    • Inner layer of Serous Pericardium
    • Covers external heart surface 
    • Also known as Epicardium
    • Areolar Connective tissue
    • Outer layer of heart wall
  23. Pericardial Cavity
    • Space between the parietal and visceral layers
    • Contains pericardial fluid
  24. Layers of Heart Wall
    • Epicardium (Visceral Pericardium)
    • Myocardium 
    • Endocardium 

    (Superficial to Deep)
  25. Myocardium
    • Thickest Layer (esp in L Ventricle)
    • Cardiac Muscle Tissue 
    • Middle Layer 
  26. Endocardium
    • Inner most layer of the heart 
    • Made of Endothelium Areolar CT
    • Lines all chambers, valves, and septa
    • Extends into blood vessels as "Tunica Intima"
  27. Atria (2)
    • Two superior chambers 
    • Receive blood  from veins
    • Pumps blood to ventricles 
    • Contain Auricles (ear like flaps)
    • Singular known as Atrium 
  28. Right Atrium 
    • Carries oxygen poor blood from systemic veins 
    • (Sup & inf Venae Cavae & Coronary sinus)
  29. Left Atrium 
    Carries oxygen rich blood from Pulmonary Veins of lungs 
  30. Septa 
    • Internal walls of the heart
    • Separate chambers 
    • 2 septa: Interatrial septum & Interventricular Septum 
  31. Interatrial Septum 
    • Between the Atria 
    • Depression "Fossa ovalis"
  32. Interventricular Septum
    Between the ventricles 
  33. Sulci 
    Grooves, indicates boundaries of Chambers 
  34. Coronary Sulci
    • Between atria & ventricles
    • Around circumference of heart
  35. Interventricular Sulci
    Between Ventricles 
  36. Heart Valves 
    • One-Way, direct blood flow
    • Passive; blood pushes them open and closed
    • 2 pairs of Atrioventricular Valves (Cuspid): Tricuspid and Bicuspid
  37. Atrioventricular Valves 
    • Cuspid Valves 
    • Tricuspid- Right side
    • Bicuspid- Left side 
    • Between the atria and ventricles 
  38. Chordae Tendineae 
    • Strong, fibrous strings 
    • Prevent cusp eversion 
    • Anchor Atrioventricular valves 
  39. Papillary Muscles
    • Conical extensions of Myocardium in ventricles 
    • Contract and pull on chordae tendineae
  40. Semilunar Valves
    • Between the Ventricles and Arteries 
    • Prevents back flow into ventricles 
    • 2 types: Pulmonary Semilunar Valve (right) & Aortic Semilunar Valve (left)
  41. Pulmonary Semilunar valve
    • In the right ventricle
    • Prevent blood flow back
  42. Aortic Semilunar Valve
    • In the left ventricle
    • Prevents back flow of blood
  43. Pectinate Muscle
    • Muscular ridges 
    • Auricles & anterior wall of atria
  44. Trabeculae Carnae
    Muscular ridges of ventricular walls
  45. Septomarginal Trabecula (Moderator Band)
    • Band of muscle in R ventricle 
    • Between interventricular septum and papillary muscle
  46. Fibrous Skeleton
    • Between atria & ventricles 
    • Dense regular C.T.
    • Encircle valves & great arteries
    • Attachment for cardiac muscle
    • Electrical insulation between atria & ventricles
    • Stabilizes valves  
  47. Histology of Cardiac Muscle Tissue 
    • Myocardium - Cardiac muscle tissue
    • Short, branched, muscle fibers 
    • Striated; 1-2 central nuclei
    • Intercalated discs - thickenings of sarcolemma at the ends of cells 
    • Muscle fibers arranged in spiral bundles 
    • Desmosomes & Gap Junctions 
  48. Gap Junctions 
    Allow the entire atrial or ventricular myocardium to contract as a single coordinated unit
  49. Demosomes 
    Hold the fibers together 
  50. Autorhythmic 
    Heart is inherent & rhythmical electrical activity 
  51. Specialized cardiac muscle fibers..
    • Are self excitable 
    • Capable of generating & conducting action potentials 
    • Acts as a pacemaker - Sets rhythm of electrical excitation stimulating contractions
    • Froms conduction system - Provides path for excitation to progress through the heart  
  52. Sinoatrial Node
    • Initiates impulse at 100 times/minute 
    • "Pacemaker"
    • Posterior wall of R Atrium 
    • Each impulse propagates through both atria via gap junctions 
  53. Atrioventricular Node 
    • Floor of R atrium, near interatrial septum 
    • AV node delays signal, allows for ventricular filling
  54. Atrioventricular Bundle 
    • Receives from AV node & conducts into interventricular septum
    • Only site where action potentials can conduct from atria to ventricles 
  55. L & R Bundle branches 
    Branches of AV bundle within interventricular spetum; conduct to Purkinje Fibers 
  56. Purkinje Fibers 
    • Within myocardium of ventricles 
    • Extended up from apex 
  57. Heart Innovation
    • Involuntary control by Autonomic Nervous System (ANS)
    • Innervated by Coronary Plexus 
  58. Coronary Plexus 
    • Innervates heart
    • 2 Parts:
    • Sympathetic pathway increases rate & force of contraction
    • Parasympathetic pathway slows heart rate (without effecting force of contraction) 
  59. Cardiac Cycle 
    • Events of one heartbeat to the next
    • Systole 
    • Diastole 
  60. Systole 
    • The contraction phase of heart chamber 
    • Blood forced out of chamber 
  61. Diastole 
    • Relaxation phase of the chamber 
    • Chamber fills with blood 
  62. Steps in Cardiac Cycle 
    • Atrial Systole 
    • Ventricular Systole & Atrial Diastole 
    • Ventricular Diastole & Atrial Diastole 
  63. Atrial Systole 
    • First step in Cardiac Cycle 
    • Atria contract; ventricles finish filling 
    • AV valve are open; semilunar valves closed 
  64. Ventricular Systole & Atrial Diastole 
    • 2nd step in cardiac cycle 
    • Atria relaxed 
    • Ventricles contract
    • AV valves close; semilunar valves open
  65. Ventricular Diastole & Atrial Diastole 
    • Last step in Cardiac Cycle 
    • Atria & Ventricles relax
    • Atria Passively fills with blood
    • Semilunar valves close; AV valves open
    • Ventricles start passively filling 
Author
michaelirby98
ID
244204
Card Set
Heart
Description
Cardiovascular system
Updated