A. T. P is stored, chemical energy in the cell, without A. T. P we would die. To make A. T. P we need glucose oxygen. Carbon dioxide and heat are the waste products. The main function of the cardiovascular system in relation to energy is to transport the oxygen and glucose to the cells, and to transport the waste products such as carbon dioxide and urea (waste product from protein digestion) away from the cells and to the lungs or kidneys. Blood is a liquid connective tissue as it is made up of living cells (red and white).
Oxygen is transported in red blood cells, attached to a protein called haemoglobin while nutrients, including glucose, are dissolved in the plasma (the liquid content of the blood). The red blood cells also carry iron; Iron is a mineral that is found in every cell in the body. It’s an important part of red blood cells, which carry oxygen as iron will attract the oxygen and without the significant amount the body would not function properly. Our cells use oxygen to make energy. Iron also is needed to keep the immune system healthy and help brain cells work normally. There are four main organs organ’s in the cardiovascular system.
Heart: The main organ of the cardiovascular system is the heart this is a fist sized organ located in the central chest cavity. The heart is a strong, powerful organ, consisting of cardiac muscle. The heart pumps continuously, without resting and without becoming tired. Its function is to pump blood to the lungs and around the body. The heart consists of four chambers and is divided into left and right by a wall of muscle called the septum. The right side of the heart consists of an atrium which receives blood returning from the body, and the right ventricle, which then pumps blood out to the lungs, via the pulmonary artery.
The left side again contains an atrium and a ventricle. The left atrium receives the oxygenated blood returning from the lungs and the ventricle then pumps this blood around the body. Due to the distance which the blood being pumped from the left ventricle has to travel, a more forceful contraction is required. For this reason the muscular wall of the left side is thicker than that of the right side. The atria and ventricles are separated by valves known as the AV valves.
The purpose of these valves is to prevent blood from flowing in the wrong direction. Following the movement of blood from the atrium, into the ventricle, the AV alve snaps shut which causes the first heart sound of the heart beat. The beat is caused by the closing of two other valves. Meaning The Sa node and Av node work together, forcing blood into the ventricles, which contract, forcing the blood to leave from the left side of the heart. The blood that enters the right side of the heart enters through veins as it is under less pressure. Blood with co2 in it will exit the right side of the heart through the pulmonary artery to the lungs where gaseous exchange occurs. Arteries and veins run parallel throughout the body, with a web-like network of capillaries, embedded in tissue, connecting them.
Arteries: The arteries carry the blood away from the heart they have thick walls due to high blood pressure and the walls begin to get narrower as they have left the heart, this also increases pressure of the blood. This means the blood carrying the oxygen and glucose will flow around the body quickly and efficiently. The walls of the arteries are made of smooth muscle and lines with thin, smooth epithelial tissue to allow the blood to move easily. The arteries have three layers and the smoothness of the inner layer enables blood to flow easily with no obstacles. Veins:
The veins carry blood back to the heart; Veins are blood vessel channels that carry waste-rich blood back to the lungs and heart. Veins carry blood at a lower pressure than the arteries, so they are not as tough as the arteries. They have three layers, which are thinner and contain less tissue than those in the arteries. The veins have valves inside them, to prevent “back flow”, which help ensure the blood flows in one direction through the veins and that the blood flows against the force of gravity Capillaries: This is where oxygen and carbon dioxide are exchanges and glucose travels into the cells.
Capillaries are very thin, fragile blood vessels that receive oxygen-rich blood from arteries, exchange oxygen and carbon dioxide and then deliver the waste-rich blood to the veins. Capillaries are only one epithelial cell thick and blood can only flow through them in a single file. The red blood cells inside the capillary release their oxygen, which passes through the wall and into the surrounding tissue. The tissue releases its waste products, e. g. carbon dioxide, which passes through the wall and into the red blood cells. The exchange occurs and the waste blood is carried back to the heart and lungs through the veins.