Question

I have contraction and relaxation inside the walls of heart who am I ​

Answer 1

The cardiac muscles ( forming both the atria and ventricle) present in the chambers of the heart undergo contraction and relaxation.

* The entire phenomenon starts with atrial contraction and ends with ventricular relaxation.

This is referred to as the cardiac cycle.

* The two main phases of the cardiac cycle are:

Systole- The chambers of the heart contract in order to pump the blood out.

Diastole- Every contraction is followed by relaxation.

Answer 2

The correct answer is Cardiomyocyte.

Explanation:

• Heart is made up of specialised muscle cells called the Cardiomyocytes.
• They are specialised in the feature that they never get fatigued.
• This is due to the presence of increased number of mitochondria per muscle cell which can produce huge amount of ATP (adenosine triphosphate).
• The contraction and relaxation of the cardiac muscles is mediated by the impulses generated from the SA or the sino-atrial node of the heart.
• This impulses cause the muscle cell membrane to get alternately depolarised by the movement of sodium and calcium ions into the cells and re-polarised by the movement of potassium ions out of the cells.
• This causes the alternate contraction and relaxation of the myofibrils in the heart muscle cells.