Final answer:
Desmosomes do not allow ions to rapidly pass between cardiac muscle cells; this function is carried out by gap junctions within the intercalated discs.
Step-by-step explanation:
The statement that desmosomes allow ions to rapidly pass from one cardiac muscle cell to another is false. Desmosomes are a cell structure that anchors the ends of cardiac muscle fibers together so the cells do not pull apart during the stress of individual fibers contracting.
In cardiac muscle cells, it is actually the gap junctions within the intercalated discs that form channels allowing the depolarizing current produced by cations to flow from one cardiac muscle cell to the next, which facilitates synchronized contractions known as electric coupling. The intercalated discs contain both desmosomes and gap junctions, where the latter are crucial for the quick transmission of action potentials and coordinated contraction of the heart.
Desmosomes are cell structures that anchor the ends of cardiac muscle fibers together, preventing the cells from pulling apart during muscle contraction. They are part of intercalated discs, which also contain gap junctions. Gap junctions are channels that allow ions to pass from one cardiac muscle cell to another, facilitating communication and coordination among the cells. This enables rapid transmission of action potentials and the synchronized contraction of the entire heart.