circulatory system

• the circulatory or cardiovascular system is considered as the main transport system of the body
• the major parts of the circulatory system is the heart, blood vessels, and blood
• the heart is a specialized muscular organ located in the middle part of the chest with its apex towards the left side
• the pericardium is a thin but very strong sac in the air that we breathe
• the apex is the lowermost part of the heart
• the pericardium has four chambers : the left and right atria in the upper chamber, and the left and right ventricles in the lower chamber
• the atria are the receiving chambers and the ventricles are the pumping chambers
• a stethoscope is an instrument used by doctors to listen to the heart and lungs
• the blood vessels are like roadways of the body where blood passes through
• the arteries are the blood vessels that carry blood away from the heart to a body
• the biggest artery which is connected to the heart is the aorta, this branches out into smaller arteries called arterioles
• capillaries are the narrowest and most numerous blood vessels
• as the blood picks up the wastes of the body, it flows towards the heart through the venules or veins
• blood is a protein-rich fluid circulating in the body
• about 55% of the blood volume is blood plasma
• red blood cells (RBCs) are tiny biconcave disks. they are also called erythrocytes
• each red blood cell contains an iron-containing protein called hemoglobin
• white blood cells (WBCs) or leukocytes are generally larger and lesser in number than red blood cells
• this results in the formation of a protein called fibrin
• the movement of blood as is distributes food and oxygen to the body cells and removes waste materials is known as blood circulation
• pulmonary circulation starts as the right ventricle pumps oxygen-poor blood into the pulmonary arteries that leads to the lungs
• systemic circulation starts as the oxygen-rich blood coming from the lungs is pumped to the different parts of the body through the left ventricle.
• the branch that carries blood to the heart is known as coronary circulation
• the 3 types of blood vessels are veins, arteries and capillaries