TH1.H1.2 Histology of Heart and Blood Vessel Walls

Cardiac Muscle:

  • The middle layer of the chambers of the heart is composed of the myocardium
  • This is made up of cardiac muscle cells and supporting tissue
  • The cytoplasm of cardiac muscle cells is mainly made up of contractile units of actin and myosin filaments organised into sarcomeres
  • Cardiac muscle cells are usually mononucleate and have a large number of mitochondria
  • Cardiac muscle cells are branched and are connected to adjacent cells by cell junctions
  • At the points of connection between adjacent cells the desmosomes and gap junctions are found in complexes known as intercalated discs
  • There are desmosomes to firmly bind the individual cells together
  • There are gap junctions to allow electrical contact between the cells
  • These gap junctions are essential for the controlled contraction of the heart chambers which provides an efficient pumping mechanism for the blood

Question:

What is a sarcomere? How are individual sarcomeres related to each other and to the cell membrane?
Why would cardiac muscle cells need a good supply of energy supplying organelles?

Privacy | Accessibility | Cookies

© 2024 University of Aberdeen

UOA Logo