Well, an endoskeleton is an internal skeleton, like humans have.
Pro: Bones do not get broke as easily, since they are inside of the body. Bones that break also heal more quickly in an endoskeleton, since they have tissue and blood surrounding it and transferring nutrients.
Con: The flesh can get easily damaged. There is no shedding with endoskeletons, so a new skeleton cannot be grown in the event of an injury.
Answer:
C, a long absolute refractory period.
Explanation:
Tetanus is not possible in cardiac muscle tissue because cardiac cells have longer action potentials and a very long refractory period compared to other cells. This helps prevent the heart from cramping and seizing up.
Coronary artery.....are the arteries that provide blood to the wall of heart !