The Cardiovascular System in a Human Body

The Cardiovascular system

The cardiovascular system is a major part of the body and is not appreciated as much as it should be. The movement of the blood is known as the cardiovascular system. The main components of the system are the heart, the blood vessels and the blood. It is made up from a cardiac cycle which is known as the movement of blood between heartbeats. However, there are 3 types of blood vessels including the arteries, veins and capillaries. These components help to supply oxygen and nutrients to all parts of the body.

The blood exits from the heart to the arteries. As the blood travels, down it gives out all the nutrients and oxygen to different parts of the body. While it gives all that out it also absorbs all the bad toxins and carbon dioxide. The blood then returns back through the veins to the lungs so more air gets transported into the blood before it goes back to the heart. This process continuously repeats without fail.

The Heart

The heart is the size of an adult’s fist and is made up of cardiac muscle. The cardiac muscle is used to control the contractions of the heart. The heart is the main function that helps the cardiovascular system operate successfully. The heart is a muscular pump that pumps blood around the body. It contains 4 chambers; the two atria collect the blood and the two ventricles pump the blood away from the heart. The septum separates the right side to the left side. The heart consists of an electrical pacemaker that helps maintain a regular heartbeat.

Blood vessels

The arteries transfer oxygenated blood away from the heart and transport it to the organs and cells. There are 3 main arteries, they are known as the left artery, the right artery and the circumflex artery. They have a thick elastic muscular wall, which stretches as blood is pumped through. The left artery supplies blood to the left side of the heart chambers. The right artery provides blood to the upper and lower right side of the heart. The circumflex artery distributes blood to the back of the heart. They have thick muscular walls which contain little passageways for the blood to travel through to the arterioles. The arterioles control the blood supply by altering their size. They are made up of a thick layer and have a high percentage of smooth muscle. They help control blood flow to the capillaries. The capillaries are known as the smallest blood vessels, they are narrow and thin to allow the red blood cells to travel down in single file, having narrow and thin walls helps the capillaries to perform their function.

Oxygen, carbon dioxide, nutrients and waste are exchanged through the capillary walls. The vein has one main function which is to return deoxygenated blood to the heart. As muscles move, they squeeze the veins flowing through them. Veins contain a series of one-way valves, and they are squashed, blood is pushed through the valves, which then close to prevent backflow. The vein has 3 different layers, the outer layer is labelled as the Tunica externa (connective tissue), and this is known as the thickest layer. The middle layer is known as the Tunica Media, which is a thin layer of smooth muscle which is squished between layers of loose connective tissue. The last layer is the Tunica intima, this layer consists of one way valves that allow the blood to flow back towards the heart.

Blood circulation

Carbon dioxide blood reaches the right atrium from the vena cava and is injected into the right ventricle. The blood transfers into the pulmonary artery, to the lungs where carbon dioxide gets delivered. The carbon dioxide then passes through to the alveoli to be expired out of the body. Oxygen then transports through the alveoli into the blood. The oxygen fulfilled blood then travels back to the heart, through the pulmonary vein into the left atrium and the left ventricle. The ventricle then pushes the blood into the aorta which carries the blood to all parts of the body, by delivering oxygen and taking away carbon dioxide, which gets taken back to the right atrium.