What are the contraction and relaxation of the heart called ?

What is the correlation between depolarization and repolarization as well as contraction and relaxation of the heart?

The relaxation of the heart is called_______

Contraction of the heart .

Name the following Muscles that function in contraction and relaxation of the heart.

X is the rhythmic contraction and relaxation in the aorta and its main arteries. What is X ?

X" is the rhythmic contraction and relaxation in the aorta and its main arteries. What is X ?

X is the rhythmic contraction and relaxation in the aorta and its main arteries. What is X ?

Describle how the contraction and relaxation of some skeletal muscles produce respiratory movements.