The heart is divided into four parts externally by grooves.
Two upper parts are called atria (auricles), and the lower ones are called ventricles.
The blood vessels found in the walls of the heart are coronary vessels which supply blood to the muscles of the heart.
The walls of the ventricles are relatively thicker than atrial walls.
In our observation we found that the heart has four chambers in it. On the left side two chambers are present, one is anterior and the other is the posterior. On the right side also two chambers present, one upper (anterior), and one lower (posterior).
The left atrium and ventricle are smaller when compared to that of right atrium and ventricle.
Observe the presence of blood vessels attached to the heart.
How many blood vessels are attached to the heart?
Are all the blood vessels are rigid? How many of them are rigid?
o you think that the stiffness/rigidity of blood vessel is something to do with circulation?
Arteries are the blood vessels which originate from the heart and supply blood to various organs in the body. They have thick walls. The largest artery is aorta. The relatively smaller one is pulmonary artery which carries blood from the heart to the lungs.
The veins are the blood vessels which bring blood from all body parts to the heart. Veins have relatively thinner walls. The vein which is at the anterior end of the right side of the heart is superior venacava (precaval vein), which collects blood from anterior parts (head and neck) of the body.
The vein which brings blood from posterior parts of the the body (hands, legs etc.) is inferior venacava (postcaval vein).
The two atria and the two ventricles are separated from each other by muscular partitions called septa. The openings between atria and ventricles are guarded by valves.
The valve present on the Right Auriculo-ventricular septum between
Right atrium and Right Ventricle is referred to as “Tricuspid Valve”. The valve present on the left Auriculo-ventricular septum between left atrium and left ventricle is referred as Bicuscid valve or Mitral valve. A major blood vessel that originate from right ventricle is Pulmonary aorta. The valves present at the region of Pulmonary aorta are called “Pulmonary valves”. A major blood vessel originates from left ventrical is systemic aorta. SCERT The valves present at the region of systemic aorta are called Systemic valves.