Heart

 Dear Friends, In this article we will learn about Heart. 

In this we will show you about the heart and its heartbeat, Functioning of heart. so, don't wasting any time lets start our this article.:-

HEART, HEARTBEAT AND FUNCTIONING OF HEART

HEART

The heart is a first size-sized muscular organ which beats continuously to act as a living pump for the transport of blood. 

The heart lies between the lungs in our chest cavity with its lower tip slightly tilted towards the left. Its wall is made  of cardiac muscles. Due to contraction and relaxation of these muscles, the heart beats continuously and pumps blood into the arteries to be transported to all parts of the body.

Our heart has four chambers, It has two auricles or atria and two ventricles. The heart is divided into two halves by a thick muscular septum. The partition between the chambers helps to avoid mixing up of oxygenated and deoxygenated blood. The right half of the heart has deoxygenated blood while the left half has pure or oxygenated blood.

FUNCTIONING OF HEART

When both the atria and ventricles are relaxed, atria gets filled with blood. The deoxygenated blood from various parts of the body enters the right atrium and left atrium receives oxygenated blood from lungs by pulmonary veins.

Now, both the atria contract simultaneously and valves open up. Blood from left atrium enters the left ventricle and form right atrium into the right ventricle.

Now, the atria relax and ventricles contract. The valves are now closed. The oxygenated blood from the left ventricles is pumped into aorta and is transported to all body parts by arteries. The deoxygenated blood from right ventricles enters into pulmonary artery and is transported to the lungs.

HEARTBEAT

We have learnt that the heart is made up of cardiac muscles. These muscles contract and relax rhythmically. This rhythmic Contraction and relaxation of muscles is known as heartbeat. The heart beats continuously throughout our life. It is an involuntary action. You can feel your heartbeat by keeping your hand on the left side of your chest.

The normal heartbeat of human being is about 72 times per minute. A doctor uses the stethoscope as a device to listen to the sound of the heartbeat.

The stethoscope consists of a chest piece that carries a sensitive diaphragm. two ear pieces and a tube joining the parts. 

Do you find any relationship between your heart and pulse rate?

Each heartbeat creates one pulse in the artery and the pulse rate per minute indicates the rate of heartbeat.

Do you think hydra and sponges also have blood? No, they do not have blood because they do not have any circulatory system. The water in which they live, brings food and oxygen as it enters their bodies. 

The heart has three layers. They are:-

1.) Epicardium:- It is the outer protective layer of the heart.

2.) Myocardium:- It is the Muscular middle layer of the heart.

3.) Endocardium:- It is the inner layer of the heart.