Respiratory system

• Breathing is when we inhale and exhale air and breathing is a physical process and breathing is voluntary
• Respiration is when food and oxygen combine together in the mitochondria and produce energy and respiration is a chemical process and it’s involuntary
• How the body prevents bacteria in the air from entering the lungs:

  1. Nose: the nasal hair filters the air and makes it free from dust and germs
  2. Nasal Cavity: this is in the back of our nose and they have 2 types. The ciliated epithelium and mucous cells. The ciliated epithelium filters the air and it has a hair like structure and move up and down and makes sure that mucous moves in one direction. The mucous cells secrete mucous and it traps the germs and has a stick like structure. These cells line the inner walls of the respiratory track till bronchioles
• The larynx is the structure that connects the trachea to the pharynx and air simply passes though it
• The trachea has rings and it’s made up of cartilage those rings maintain the tracheas shape and allow it to expand and contract/stretch and they keep the windpipe open
• The bronchi has tiny hair called cilia and it’s a muscle that brushes up and down and has mucous that collects germs that might harm the lungs
• The lungs are divided into 2 sections

  1. the right lung: it has three lobes
  2. the left lung :it has 2 lobes to give the heart some space

  when air goes in the lungs they get divided into branches
• the bronchioles are the smallest airways in the lungs and are located in the lungs and they have branches of bronchi in each lung and on every tip, they have air sacs called alveoli
• The alveoli are the site of gas exchange in the lungs and they’re full of oxygen and surrounded by blood capillaries
• The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing and this is called diffusion as oxygen moves from the alveoli to the blood through the capillary walls that is from higher to lower concentration
• Diaphragm begins to move downwards and flattens during inhalation and this allows the lungs to expand and accommodate air and this process lowers air pressure and during exhalation, the diaphragm moves to its original position and gradually moves the air outwards and this also increased the air in the lungs
• • Aerobic respiration takes place in the presence of oxygen and produces carbon dioxide and water and its formula is :glucose + oxygen = carbon dioxide + water + energy.
  • this is a chemical change and can’t be reversed
• • Anaerobic respiration takes place in the absence of oxygen and produces lactic acid which is poisonous for your body and makes a sharp pain in your side muscles
  • formula is: glucose=lactic acid+energy
• • cigarettes contain nicotine , tar , carbon monoxide and tobacco
• 1. Smokers get addicted to cigarettes because the nicotine makes it hard to leave it and your body gets used to it and it starts needing it
  2. nicotine makes blood vessels narrower than normal by depositing on the outer lining of the blood vessels
• Carbon monoxide replaces oxygen in the haemoglobin molecules so less oxygen reaches the cells and tissues
• Tar contains more than 4000 chemicals including benzene , formaldehyde , arsenic and lead
• Cancer is when abnormal cells grow uncontrollably and spread into other parts of the body
• Tobacco causes lung cancer and throat cancer
• Arsenic damages skin and lungs
• Chronic bronchitis is where there are long term inflammation of the bronchioles due to irritants such as cigarette smoke and polluted air
• Tar causes lung cancer because the cells keep dividing uncontrollably and causes an out growth called a tumour which is cancer
• Tar coats the inside of the lungs , including alveoli causing damage which makes gas exchange difficult
• Particulates and tar damage the cilia and as a result , smokers cough to move the mucous and they’re more likely to get bronchitis
• Carbon monoxide reduces the amount of oxygen that the blood can carry and the circulatory system has to work harder , causing heart disease
• When we exercise lightly and not harshly our body respires aerobically and our heart rate is normal and we don’t get tired since we have enough oxygen to respire but when you exercise harshly , your body starts respiring anaerobically and your heart rate increases because of how hard you’re exercising don’t have enough oxygen than you’re using up and you produce lactic acid which is poisonous