Human breathing

Cards (28)

  • Respiratory system

    • Located in the chest (thoracic) cavity
    • Function is breathing
  • Breathing
    Taking in oxygen from the air and letting out carbon dioxide and water vapour
  • Respiration
    Release of energy from food, takes place in the cells of the body
  • Lungs (and heart)
    • Protected by the ribs and the breast bone
    • Surrounded by 2 pleural membranes filled with pleural fluid to lubricate and reduce friction
  • Nose and mouth
    • The human breathing system starts here
    • Breathing in through the nose traps dirt, pollen and bacteria, and warms and moistens the air
  • Epiglottis
    Small flap of cartilage that stops food from entering the trachea
  • Larynx
    Contains the vocal cords that vibrate to produce sound
  • Trachea
    Also called the windpipe, surrounded by C-shaped rings of cartilage to prevent airway collapsing, carries air from nose to lungs
  • Bronchi and bronchioles
    Bronchi carry air from trachea into lungs, bronchioles carry air from bronchi to alveoli
  • Alveoli
    Tiny air-sacs in the lungs where gas exchange occurs, have a very large total surface area
  • Alveoli
    • Wall and capillaries are only one cell thick to aid diffusion
    • Surrounded by dense network of capillaries
    • Moist for rapid diffusion of gases
  • Gas exchange
    1. Oxygen passes from alveoli into capillaries and binds to haemoglobin
    2. Carbon dioxide and water pass from capillaries into alveoli
  • Breathing
    Normal resting rate is 12-18 breaths per minute
  • Inhaling
    Intercostal muscles contract, diaphragm contracts, chest cavity volume increases, air pressure decreases, air is sucked in
  • Exhaling
    Intercostal muscles relax, diaphragm relaxes, chest cavity volume decreases, air pressure increases, air is forced out
  • Inhaled and exhaled air have different compositions
  • Effect of exercise on breathing rate
    Fitter people have slower resting breathing rate and recover more quickly after exercise
  • Control of breathing rate
    Medulla oblongata detects changes in blood CO2 levels and sends messages to adjust breathing rate
  • Asthma
    Common breathing disorder with symptoms of coughing, wheezing, breathlessness and chest tightness
  • Cause of asthma
    Narrowing and inflammation of bronchi and bronchioles, triggered by allergens
  • Asthma prevention and treatment
    Removing triggers, using bronchodilator inhalers to open airways
  • Smoking affects many parts of the body and can lead to serious diseases like cancer, emphysema and heart disease
  • Substances in cigarette smoke
    Nicotine (addictive), tar (carcinogenic), carbon monoxide (toxic)
  • Respiratory diseases
    • Asthma
    • Bronchitis
    • Pneumonia
    • Emphysema
    • Cystic Fibrosis
    • Lung Cancer
    • Tuberculosis
  • Bronchitis
    Inflammation of bronchiole tubes, causes coughing, difficulty breathing and heavy chest
  • Pneumonia
    Inflammation of lungs due to infection, alveoli fill with fluid making it difficult to breathe
  • Emphysema
    Chronic breathlessness caused by breakdown of alveoli walls, decreasing surface area for gas exchange
  • Cystic Fibrosis
    Genetic disorder causing excess mucus production that clogs bronchial tubes and obstructs breathing