MEDICAL PHYSIOLOGY

Detailed explanation-1: -Intercalated discs are part of the cardiac muscle sarcolemma and they contain gap junctions and desmosomes. Contractions of the heart (heartbeats) are controlled by specialized cardiac muscle cells called pacemaker cells that directly control heart rate.

Detailed explanation-2: -Intercalated discs are part of the cardiac muscle sarcolemma, so they also contain gap junctions for depolarization between muscle fibers and desmosomes that hold the fibers together during cardiac muscle contraction (Fig. 3b).

Detailed explanation-3: -Cardiac muscle cells (cardiomyocytes) are striated, branched, contain many mitochondria, and are under involuntary control. Each myocyte contains a single, centrally located nucleus and is surrounded by a cell membrane known as the sarcolemma.

Detailed explanation-4: -One feature unique to cardiac muscle is the presence of intercalated discs. These were originally believed to be another type of striation or stripe. From studies of these bands with the electron microscope it can be seen that these discs represent the end-to-end junction of adjacent cardiac muscle cells.

Detailed explanation-5: -Intercalated discs are characteristic features of cardiac muscles. They help us to identify the cardiac muscle under microscope. Intercalated discs are communication junctions between cardiac muscle cells that help in the rapid transmission of signals and allow heart cells to contract as a unit.