Heart Test

Card Set Information

Heart Test
2012-03-29 21:12:11

ventricle system
Show Answers:

  1. how many times must the blood pass through the heart to complete one full circulatory cycle?
  2. l. ventricles function
    to pump blood through the aortta and out to the rest of body
  3. right ventricle
    pump blood out of the pulmonary trunk to the lungs where blood is reoxygenated
  4. what is a cardiac cycle
    when both ventricles and the atria go through a rest and active cylce
  5. Why do the AV valves close?
    • because the ventricle contracts, increasing the blood pressure, and shutting the valve "doors" closed.
    • one way doors
    • when the ventricles contract, the semilunar valves (located in the bases of 2 large arteries open
  6. systolic blood pressure
    measures the pressure in the arteries at the peak of contraction
  7. diastolic pressure
    the pressure in the ventricles when the ventricles are relaxing
  8. sinoartial node
    • the pacemaker of the heart
    • intrinsic control of the heart rhythm
    • initiates heartbeat and causes the atria to contract
    • if of part of the heart becomes off rhythm, the heart doesn't recieve adequate oxygen and slowly dies, causing a heart attack
  9. AV node
    conveys the stimulus and initiates contraction of the ventricles
  10. lub
    AV valves closing
  11. dub
    semilunar valve closing
  12. SA node (more)
    • bundle of nerves in right atria
    • signals to AV node
    • to signal the his fibers that cause the atria to contract
  13. extrinsic controls of the heart
    • medulla oblongata
    • hormones (epinephrine)
  14. parasympathetic
    slows heart rate
  15. sympathetic
    speeds up heart rate
  16. carroted arteries
    brings blood to the head
  17. jugular vein
    returns blood from the head
  18. vascular pathways
  19. angina pectoris
    chest pains due to heart itself not recieving enough oxygen
  20. atrioventricular
    valves that prevent backflow between lower and upper heart chambers
  21. pericardium
    double membrane sac that encloses, supports, and protects the heart.
  22. chordae tendineae
    filaments that help anchor the heart valves in place during pumping
  23. endocardium
    the innermost layer of the heart
  24. coronary arteries
    • blod vessels that supply the metabolic needs of the heart itself
    • the heart, although is full of blood and circulates blood still needs to be brought blood via the circulatory system
  25. myocardium
    • middle layer of the heart
    • layer that actually does the contracting
  26. ventricles
    heart chambers that recieve returning blood from veins
  27. capillaries
    where nutrient and gas exhange occure
  28. veins
    carry blood to the heart
  29. arteries
    carry blood away from the heart
  30. artery characteristics
    • strong, stretchy to handle changes in blood pressure
    • middle layer of artery wall is smooth muscle that constricts to regulate blood flow
  31. characteristics of veins
    • have valves that prevent backflow
    • dont have smooth muscle wall
    • thinner than arteries
    • bring blood back to the heart--works using gravity
  32. atrioventricular valves
    occur between the atria and ventricles
  33. pulmonary circuit
    pulmonary trunk (right ventricle)-->pulmonary arteries-->lungs-->4 pulmonary veins that bring blood back to the heart
  34. athersclerosis
    • build up of plaque under the inner lining of the arteries
    • could cause as thrombus to form
  35. 4 strategies used by the veins to move low pressure blood back to heart
    • 1. larger lumens to prevent backflow
    • 2. skeletal muscle activity milks blood through the veins throught relaxing and contracting movement
    • 3. inhaling causes blod pressure to drop in the thorax causing the veins near heart to expand
    • 4. valves
  36. layers of the heart
    • outer: epicardium
    • middle: myocardium
    • inner: endocardium