Natural selection my friend
Answer:
Neighboring cardiac muscle cells in the walls of heart chambers have specialized cell-to-cell contacts that electrically and mechanically link the cells together, permitting the immediate passage of muscle impulses. These cell-to-cell contacts are called <u>intercalated discs.</u>
Explanation:
Intercalated discs can be described as unique structures present between the cardiac muscles of the heart. The intercalated discs play a major role in making the cardiac muscles contract in a rhythm so that the heart can pump blood in a regular fashion and it hence regulates the effective functioning of the heart. The intercalated discs are the structures that join on cardiac muscle to another and is involved in the transmission of chemical messages between them.
Hmm due to some thinking and having some knowledge of the body. I believe the crani refers to the skull. Crani could be considered short for cranium which refers to the skull. I hope that this helps!
<span>284 km in 2 million years.</span>