Transport in animals

• Blood in the left side of the heart has come from the lungs, and it is oxygenated.
• Oxygenated blood is sent around the body. Some of the oxygen is taken up by the body cells that need oxygen for respiration. When this happens, the blood becomes deoxygenated.
• Deoxygenated blood is brought back to the right side of the heart. It then goes to the lungs, where it becomes oxygenated again.
• The double circulatory system is when the blood passes through the heart twice.
• Blood vessels that take the blood to and from the lungs are called the pulmonary system.
• Blood vessels that take the blood to the rest of the body and back are called the systemic system.
• Double circulatory system is found in all mammals, reptiles, and birds.
• Fish have a circulatory system where blood only passes through the heart once. This is called a single circulatory system.
• When blood flows through blood vessels it loses a lot of pressure that was given to it by the pumping of the heart.
• In a mammal, low pressure blood is delivered back to the heart, which raises the blood pressure before sending it back to the rest of the body.
• In a fish, low blood pressure is carried around the body, meaning that the blood travels slowly.
• The function of the heart is to pump blood around the body.
• The heart pumps due to the cardiac muscle which contracts and relaxes regularly.
• The heart consists of 4 chambers.
• The upper chambers of the heart are called the atrium, and the lower chambers of the heart are called the ventricles.
• The left and right sid eof the heart are separated by the septum.
• The left atrium receives blood from the pulmonary vein, which has come from the lungs.
• The right atrium receives blood from the vena cava, which has come from the rest of the body.
• From the atria, blood flows through the ventricles and the ventricles pump the blood out of the heart.
• Ventricles pump blood out of the heart by contracting their muscles, which squeezes inwards on the blood and pushes it out.
• The blood in the left ventricle is pumped into the aorta which takes the blood to the rest of the body.
• The blood in the right ventricle is pumped into the pulmonary artery which takes the blood to the lungs.
• The atria receive blood and the ventricles pump it out.
• Ventricles have thicker and more muscular walls than the atrium.
• The right ventricle pumps blood to the lungs which is very close to the heart, however the left ventricle pumps blood to the rest of the body. The left ventricle has a very thick wall in order to do this because the blood flowing to the lungs has a much lower pressure than the blood in the aorta.
• Blood vessels outside of the heart are called coronary arteries. They supply blood to the heart muscles.
• Causes of coronary heart disease are stress, smoking, diet, obesity, and genetics.
• An average person's heart beat 60-75 times per minute.
• Pulse rate is the way to measure your heart rate.
• A faster heart rate, means a faster delivery of blood to the muscles, providing oxygen
• The pacemaker sends electrical signals through the walls of the heart which makes the muscle contract.
• There are one way valves between the left atrium and ventricle and between the right atrium and ventricle. This is called an atrioventricular valve.
• The atrioventricular valve stops the blood flowing back into the atrium from the ventricle.
• There are three main kinds of blood vessels: arteries, capillaries, and veins.
• When blood flows out of the heart, it enters the arteries.
• When the blood flows into the arteries it is at a very high pressure due to the ventricles forcing the blood out. This means that the arteries have very thick walls to withstand the pressure.
• The blood does not flow smoothly through the arteries. It pulses through as the ventricles contract and relax.
• Arteries have an elastic tissue in their walls which can stretch and recoil with the force of the blood, to help the blood flow smoother.
• Arteries gradually divide and form smaller vessels called capillaries.
• Capillaries are very small and go to every part of the body. No cells are far away from a capillary.