Science

• organ system is a group of organs that work together to perform a specific function
• there are two types of organ systems ; respiratory and circulatory system
• the body gets its energy from a chemical reaction that takes place in a cells . that chemical reaction is called respiration
• the fuel for this chemical reaction comes from carbohydrates and fat which is in the foods we eat
• the carbphydrates and fat are broken down into small molecu;es like glucose
• the lungs provide oxygen that BURNS the glucose
• Aerobic means with air
• and anaerobic means without air
• during the process of respiration the energy that holds the glucose molecule togather is released
• this energy is used by cells to do work, move around or stay alive
• when there isn't enough oxygen available to burn all the glucose aerobically, some of it will be burned without oxygen (anaerobically)
• carbon dioxide and water are produced as waste products
• when body cells are producing energy they use up oxygen and produce carbondioxide and water
• the air we exhale contains water vapour
• the air we inhale contains oxygen which is carried by the blood to the cells and the carbon dioxide is carried out of the cells by the blood
• the lungs are technically 2 plastic pouches lying inside the rib
• the lungs sre connected outside by the windpipe
• the windpipe is also called the trachea
• the trachea is divided into a smaller tube called the bronchi
• the brochi is further divided into more smaller tubes called bronchioles
• after more branchingthe tubes end up in thin walled tiny air sacs called alveoli
• in the lining of the air passages there are 2 types of cells one type is covered with tiny hairlike cilia and the otheer is covered in a sticky liquid called mucus
• the main function of mucus is to stop any dust particle or bacteris from entering the windpipe
• the dust particles and the bacteria stick to the mucus and the cilia carry up the mucus towards the mouth were it is then swallowed
• oxygen moves into the blood by diffusion
• the aveoli are well adapted to speed up the process of the oxygens diffusion
• there are thousands of aveoli providing a large surface are for the blood
• the walls of the aveoli are very thin so that oxygen can diffuse easily through them
• the lining of the aveoli is quite moist so that the oxygen can easily disslove
• the aveoli are surrounded by tiny blood vesseld called capillaries . they carry the oxygen away
• carbon dioxide enters the lungs from the air sacs (alveoli) and then leaves the body as it passes out of the lungs.
• Lungs can hold about 5 liters of oxygen
• meanwhile when you are sleeping only 500cmcube is exchanged
• during excersize you breathe in an extra 3 litres of oxygen
• Breathing is a simple way of exchanging gases between lungs and the surrounding air
• respiration is when glucose is broken down
• respiration takes place in the powerhouse of cell aka mitochondria
• in anaerobic respirattion is broken down into lactic acid
• there are 2 types of circulatory system , open and closed
• the open circulatory consists of a heart and no blood vessels the heart has a tube shape and it pumps blood on to the muscles . the heart has holes in it so that the blood gradually comes back , the blood moves with the body movement