Question

1. Skeletal muscle fibers do not have gap junctions, but heart muscle cells do. Why do you think there is this difference? In other words: Why would it be bad to connect skeletal muscle fibers with gap junctions?
2. What is the benefit of having gap junctions in the heart?

Answer 1

Gap junctions

Explanation:

• Skeletal muscle also called as voluntary muscle, is anchored to bone by tendons and is used to effect skeletal movement in activities such as locomotion and maintaining posture
• Muscle associated with heart is called cardiac muscle is also an involuntary muscle but is more akin in structure to skeletal muscle
• Both cardiac and skeletal muscles are striated, they contain sarcomeres and are packed into highly regular, repeating arrangements of bundles
• Skeletal muscle do no have gap junctions because they are not single cells
• The gap junctions, which are protein-lined tunnels, allow direct transmission of the depolarizing current from cell to cell, across the chambers of the heart, so that the cells contract in unison
• Because of the way these gap junctions function, the cardiac muscle cells are said to be electrically coupled