Cardiac Muscle

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Across
  1. 3. This is a small upward deflection on the ECG
  2. 4. In muscle, this period is the time interval during which a second contraction cannot be triggered
  3. 6. cardiac muscle has a smaller intracellular reserve of ______ ions
  4. 7. The SA node is a ______ pacemaker
  5. 9. The instrument used to record the changes is called
  6. 11. The mechanism of contraction is similar in cardiac muscle is similar to ________ muscle
  7. 13. the action potential travels along the conduction system and spreads out to excite these fibres
  8. 17. Intercalated discs contain these to hold the fibres and gap junctions together.
  9. 19. This sets the rhythm of electrical excitation that causes contraction of the heart.
  10. 21. __________ Q wave may indicate a myocardial infarction
  11. 24. irregular transverse thickenings of the sarcolemma are called
  12. 25. The third wave is a dome-shaped upward deflection called the
  13. 28. the phase of contraction
  14. 29. QRS complex begins with a ________ deflection
  15. 30. These allow the entire myocardium of the atria or the ventricles to contract as a single, coordinated unit.
  16. 31. The source of this electrical activity is a network of specialized cardiac muscle fibers called
Down
  1. 1. First step in the action potential occurs of a contractile fiber
  2. 2. High blood K+ level causes
  3. 5. Cardiac excitation normally begins here
  4. 8. The phase of relaxation.
  5. 10. These large diameter fibres rapidly conduct the action potential beginning at the apex of the heart upward to the remainder of the ventricular myocardium
  6. 12. A recording of electrical signals is called
  7. 14. The spontaneous depolarization in SA node is a ______ potential
  8. 15. AV bundle is also called as
  9. 16. ECG involves measuring the time spans between waves called
  10. 18. This is a period of maintained depolarization in contractile fibre
  11. 20. The recovery of the resting membrane potential takes place during this phase of action potential
  12. 22. Larger P waves indicate enlargement of
  13. 23. This cell organelle is larger and more numerous in cardiac muscle fibers than in skeletal muscle fibers.
  14. 26. Number nuclei present in a muscle cell
  15. 27. In muscle, this period is the time interval during which a second contraction cannot be triggered