The Heart

Heart

• Pump of the circulatory system.

• It is a strong, hollow muscle about size of a clenched fist.

• It is located slightly to the left of our chest.

• When heart beats, its muscle tissues work together to push blood through the blood vessels to every part of the body.

• A wall of tissue separates the heart into two sides – the right and the left.

• The right side of the heart pumps blood to the lungs.

-It collects blood that has traveled through the body.

-This blood is low in oxygen.

• The left side of the heart pumps blood to the different organs of the body.

-It collects oxygen-rich blood coming from the lungs.

-The heart wall, called septum, keeps the blood in each side from mixing.

• The Heart is divided into four parts or chambers.  Each of the two upper parts called an atrium.

-The Atrium is a thin-walled chambers.

-It collects blood as it enters the heart. 

-Blood flows into each atrium from the blood vessels.

• The two lower chambers of the heart are called ventricles. 

-There is a right ventricle and left ventricle.  Each ventricle has thicker and more muscular walls than the atrium.

-Ventricles are the pumping chambers that push blood out of the heart.

-They are responsible for keeping the blood moving in all parts of the body.

• The Heart also has parts that act like doors.  These are called Valves.

-Valves are flaps of tissue that open and close, allowing blood to flow in only one direction.

-They keep the blood moving in the right direction.

-As the heart muscles squeeze together, some of its valves are closed.

-They keep the blood from flowing backward other valves are opened as the blood moves forward.  The blood then flows out of the heart.

• When the heart muscles tighten, they forced blood through the blood vessels.  This tightening of the muscles is called a heartbeat.

-The heart beats an average of 70 to 80 times a minute.

-The speed of your heartbeat depends on your activities.

Tags: blood, blood circulation, circulatory system, heart, human circulatory system, Science, The sciences

Category: Circulatory System