Body Structure and Function Ch 12

  1. What is the function of the heart?
    • Pumps blood
    • creates blood pressure
    • circulates oxygen, nutrients, and other substances
  2. Where is the heart located?
    In the mediastinum, the area between the lungs in the thoracic cavity
  3. What are the three pericardial membranes that enclose the heart?
    • Fibrous pericardium - outer
    • Parietal pericardium
    • visceral pericardium
  4. Function of of serous fluid
    When located between the parietal and visceral membranes, the fluid prevents friction as the heart beats
  5. Fibrous Pericardium
    • Made of fibrous connective tissue 
    • loose fitting sac
    • surrounds the heart and extends over the diaphragm of the great vessels
  6. Myocardium
    Cardiac muscle tissue, forms the walls of the four heart chambers
  7. Endocardium
    • Lines the chambers and covers the heart valves 
    • Prevents abnormal clotting
  8. Atriums
    Receive blood from the veins
  9. Ventricles
    Pump blood into the arteries
  10. Interatrial Septum
    Separate the left and right atriums
  11. Interventricular Septum
    Separate the left and right ventricles
  12. Tricuspid Valve
    Prevents backflow of blood from the right ventricle to the right atrium when the right ventricles contracts
  13. Right Atrium
    Receives blood from the upper body by he superior vena cava lower from the lower body by the inferior vena cava
  14. Left Atrium
    Receives blood from the lungs by the way of four pulmonary veins
  15. Mitral Valve (Bicuspid)
    Prevents back flow of blood from the left ventricle to the left atrium when the left ventricle contracts
  16. Right Ventricle
    • Pumps blood to the lungs through the pulmonary artery
    • relatively thin walls
  17. Pulmonary Semilunar Valve
    Prevents back flow of blood from the pulmonary artery to the right ventricle when the right ventricle relaxes
  18. Left Ventricle
    • Thicker walls than right ventricle 
    • Pumps blood to the body via the aorta
  19. The right side of the heart receives _____ blood from the body and pumps it to the _______.
    Deoxygenated, lungs
  20. The left side of the heart receives _____ blood from the _____ and pumps it to the _______.
    Oxygenated, lungs, body
  21. "Lubb"
    Created by the closure of the AV valves during ventricular systole
  22. "Dubb"
    created by closure of the aortic and pulmonary semilunar valves
  23. Heart murmur
    Created by an improper closure of the valves
  24. Electrocardiograph, (ECG)
    Depicts the electrical activities of the heart
  25. SA Node
    • Located in the wall of the right atrium 
    • initiates each heart beat
    • More permeable to Na+ ions 
    • depolarize more rapidly than any other part of the myocardium
    • action potential spreads rapidly throughout the myocardium because of the intercalated discs at adjacent cells
  26. Coronary Vessel Pathway
    Ascending aorta to right and left coronary arteries to smaller arteries to capillaries to coronary veins to the coronary sinus to the right atrium
  27. Coronary circulation supplies _______ blood to the ______.
    Oxygenated, myocardium
  28. Myocardial infarction
    Death of an area of myocardium due to the lack of oxygen
  29. What does an obstruction of a coronary artery cause?
    Myocardial infarction, heart attack
  30. Cardiac output
    Amount of blood pumped by a ventricle in one minute
  31. Stroke volume
    Amount of blood pumped by a ventricle in one beat; average 60-80
  32. Cardiac output equation
    Stroke volume x pulse, 5 to 6 liters average
  33. Medulla
    Contains the cardiac centers: the accelerator center and the inhibitory center
  34. Sympathetic vs Parasympathetic
    Sympathetic - impulses to the heart increase rate and force contraction

    parasympathetic - impulses vagus nerve to the heart decrease heart rate
  35. Pressoreceptors
    • In the carotid and aortic sinuses
    • Detect changes in the blood pressure
  36. Chemoreceptors
    • In the carotid and aortic bodies
    • detect changes in the oxygen level of the blood
  37. Ejection fraction
    Percent of its total blood that a ventricle pumps per beat, average 60-70%
  38. Arrythmias
    Irregular heart beats, can be harmless to life threatening
  39. What happens if part of the conduction pathway does not function properly?
    The next part will initiate contraction but at a slower rate
  40. Right and left bundle branches
    • In the interventricular septum
    • transmit impulses to the purkinje fibers in the ventricular myocardium which complete ventricular systole
  41. AV bundle (bundle of his)
    • In the interventricular septum
    • first part of the ventricle to depolarize
  42. AV Node
    • In the lower interatrial septum
    • depolarization spreads to the AV node and to the atrial myocardium and brings about atrial systole
  43. What generates the heart beat?
    The heart generates its own beat but the nervous system brings about changes due to reflexes
  44. Normal heart rate
    60-80 BPM
  45. Bradycardia
    heart rate less than 60
  46. Tachycardia
    Heart rate greater than 100
  47. Ischemic
    deprived of blood supply
  48. Cardiac cycle
    The sequence of events in one heartbeat
  49. Systole
  50. Diastole
  51. Which fluid prevents frictions of the layers of the heart?
    Serous fluid
  52. Which part of the heart is responsible for pumping the blood?
  53. which area is the heart located?
  54. What supports the flaps of the valves?
    Papillary muscles and chordae tendineae
  55. how many valves of the heart are there?
  56. What is the general function if valves?
    Prevent backflow
  57. What is the hormone responsible for lowering blood volume which lowers blood pressure?
    Atrial natriuretic peptide (ANP)
  58. The inferior vena cava returns blood from ___ to ____
    The lower body to the right atrium
  59. What does diastole and systole mean?
    • Relaxation - D
    • contraction - S
  60. T or F: in the cardiac cycle, the flow from the atria to the ventricle flows actively
    False: passively
  61. What is the definition of stroke volume?
    • The amount of blood pumped by a ventricle in one beat
  62. Which nerves or impulses are used by the cardiac accelerator center?
  63. T or F: the vagus nerve carries impulses from the medulla to increase heart rate
    False: decrease
  64. Pain in the heart is caused by what?
    Lack of oxygen
  65. the blood from the lungs goes through ___ to ___
    Pulmonary vein to the left atrium
  66. T or F: during one cardiac cycle, the atrial contracts first followed by the ventricles contract together
    False: both atriums contract followed by both ventricles contracting together
  67. T or F: the sequence of blood flow is from the right heart to the lungs to the right heart to the body
  68. What is the function if the SA node
    Initiates the heart beat, "natural pacemaker"
  69. What is the name that is used for the percentage of blood that is in the ventricle that is pumped during systole
    Ejection fraction
  70. What does the medulla regulate?
    Heart rate and blood pressure
  71. cardiac conduction pathway
    SA node , AV node, bundle of his, right and left bundle branches, purkinje fibers
  72. What chambers of the heart in the upper part?
  73. When bp increases, atriums produce what hormone?
  74. The coronary sinus is the union of __ and returns blood to ____.
    vein, atrium
Card Set
Body Structure and Function Ch 12
Functions of the Heart