The Cardiac Skeleton

• • The cardiac skeleton of the heart is the connective tissue upon which the heart is built. It supports and reinforces the heart, distributes heart muscle contractions, isolates atrial and ventricular muscle cells, and gives the heart elasticity.
• Each cardiac muscle cell is wrapped in a strong elastic sheath, and adjacent cells are tied together by fibrous cross-links or "struts"
• Connective tissue layers are continuous with bands of dense connective tissue that

  • encircle bases of pulmonary trunk and aorta
  • encircle valves of heart
  • connect fibrous rings surrounding openings for heart valves
  • extend into cardiac muscle separates atria and ventricles
• Extensive connective tissue network is called the cardiac skeleton of the heart
• Functions of cardiac skeleton include

  • stabilizing positions of muscle cells and valves in heart
  • providing physical support for cardiac muscle cells and blood vessels and nerves within myocardium
  • distributing forces of contraction
  • providing elasticity that returns heart to original shape after contraction
  • physically isolating atrial muscle cells from ventricular muscle cells