Where are cardiac muscles used? Are they voluntary?

Heart

Not voluntary.

Explanation:

The heart is made up of special muscle called the cardiac muscle that contains interconnected muscle fibres which are supplied with blood through the coronary artery. Also so that the waves of contraction can travel throughout the mass of the muscle.

Cardiac muscle is in the heart.

No, they are not voluntary.

i believe it is 40–40–20%

explanation:

1 a

2 d

3 a

4 c

explanation: