TRANSPORTATION IN ANIMALS (WORKING OF HEART)

WORKING OF HEART ❤

The muscular organ which is located near the chest slightly towards the left in the thoracic region.The heart is the main pumping organ of the body.

It makes the sound of LUB-DUB due to the closing and opening of valves present in the heart.

It is made up of cardiac tissue.

The human heart is divided into four chambers which are involved in the transportation of oxygenated and deoxygenated blood.

The upper two chambers are called atria whereas the lower two chambers are called ventricles.

It is surrounded by a tough two layered sac called pericardium.

 The pericardial fluid is secreted in pericardial cavity between pericardium and heart which reduces the friction between heart wall and surrounding tissues when heart is beating.

Height is divided by Septa into two halves:  right and left. 

 Each have consists of two communicating chamber.

The upper auricle or Atrium and the lower larger ventricle.

VALVES

There are walls between left Atrium and left ventricle and between right Atrium and right ventricle. these walls provide one way passage and prevent the return of the blood.  that means these two who was permit the flow of blood from Atrium to ventricle and not in the reverse order.  

BICUSPID VALVE-Between left Atrium and left ventricle.

TRICUSPID VALVE- Between right Atrium and right ventricle .

just look at the picture. We will be working on a box diagram of the 

heart later.

FLOW OF THE BLOOD 

Pathway of circulation

DOUBLE CIRCULATION

The Blood circulation in the human heart is double circulation. This means that the blood passes through the heart twice for each circuit of the body.   

One circulation involves the entry of blood from all body parts into the heart,  this blood is deoxygenated which goes to the lungs for oxygenation. 

 The second circulation involves the entry of oxygenated blood from lungs into the heart and then its distribution to all parts of the body.

 Double circulation is made possible because the human heart is divided into two halves. One pumps deoxygenated blood(RIGHT) to the lungs and other half pumps oxygenated blood(LEFT) to the rest of the body. 

Reptiles have 3 chambered heart.

Only exception is crocodiles with 4 chambered heart.

Mammals have left aortic arch while birds have right aortic arch.

CARDIAC CYCLE

The most vital function of the heart is heart beats which takes place all the time throughout one's life.

The sequence of events which takes place during completion of one Heartbeat is called cardiac cycle. 

It involves repeated rhythmic contraction and relaxation of heart muscles.

 Contraction is called systole and relaxation is called diastole.

Cardiac Cycle link-

https://drive.google.com/file/d/1J3Z_mHlmMj4x428yULeCP3df5ayhx9Ci/view?usp=drivesdk

BLOOD PRESSURE…

MEASURED BY SPHYGMOMANOMETER.

Systolic pressure is on artery due to ventricular contraction (120mm hg)

Diastolic pressure is on artery during ventricular relaxation(80mm hg)

Note-

Pulmonary circulation moves blood between the heart and the lungs. It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body.