This is not a muscle (eg biceps brachi etc) but a muscle type. Chardiac muscle is a specialised muscle type that can contract as well as carry a current. There are also special cells in the heart,...
There's more than one chemical that causes contraction. The neurotransmitter (usually acetylcholine) is released from the nerve and excites the muscle. There is a change in calcium, sodium and...
The large, hollow organs of the digestive tract contain a layer of muscle that enables their walls to move. The movement of organ walls can propel food and liquid through the system and also can mix...