Topic : Heart

UNIT – Circulatory Pathways

Submitted ByJisha George

Natural ScienceReg No: 18114386006

Position of Heart

External Structure of Heart

Internal Structure of Heart

Different Valves of Heart

Working of Heart

Heart Beats (Systole & Diastole)

Circulatory System of Human Heart

Additional Information

Sub Topics

Heart is a completely muscular organ

In man the position of the heart is behind the sternum in the

thoracic cavity between the lungs tilted slightly towards left.

A person’s heart is generally as large as his or her

fist

Position of Heart

The adult heart is approximately 12cm long, 9 cm broad and weight 300gms.

Roughly conical in shape with the upper end broader than the lower.

A double membrane called pericardium covers the heart.

The pericardial fluid that fills the space between the membrane protects the heart and helps it to function smoothly.

External structure of Heart

Human heart has four chambers The upper two chambers are called atria and the two lower chambers are called ventricles.

The two atria and the ventricles are separated by muscular walls.

Left atrium opens to the left ventricle, Right atrium opens to the right ventricle.

Internal structure of Heart

Tricuspid valve present between Right atrium and right ventricle.

Bicuspid valve present between left atrium and left ventricle.

Different Valves of Heart

Pulmonary valve present between right atrium and pulmonary artery.

Aortic valve present at the beginning of the arteries.

The contraction of the heart chambers is called is called systole.

The state of rest is called diastole

A heart beat consist of one systole and one diastole.

NORMALLY, THE HUMAN HEART BEATS 72 TIMES IN A MINUTES.

Heart Beats

A special type of muscles at the upper of the

right atrium initiates movement and controls

the rate of heart beat. This part is called the

SINO-ATRIAL NODE

Working of Heart

Sino-Atrial Node

Circulatory System

Additional Knowledge Your heart can keep beating even if it is separated from the body

because it has its own electrical impulse.

Your heart will pump nearly 1.5 million barrels of blood during your lifetime, enough to fill 200 train tank cars.

Your left lung is smaller than your right lung to make room for your heart.

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