Lung disease

• how does lung cancer form

  It is an abnormal cell growth that rapidly forms a mass of cells, or tumor that interferes with breathing.
• why does the tumour continue to grow

  it has no method of programmed cell death
• how does the tumour survive


  develops its own blood supply (vascularisation)
• how does the tumour interfere with the normal working of the lungs


  squeezes against blood vessels

  may enter lymphatic system - secondary tumours
• what are some symptoms of COPD


  -Shortness of breath

  -chronic cough

  - chest tightness

  - wheezing

  - difficulty breathing when exercising
• How does it effect goblet cells in the ciliated epithelium

  become enlarges- produce more mucus
• How does this affect cilia in the trachea

  destroys them- prevents them sweeping away mucus from lungs
• why is the execs of mucus bad


  - contains bacteria, dust and other microorganisms

  - can block narrow bronchioles, causing coughing, scar tissue, infection
• Why is the attraction of phagocytes to the infection bad?


  Phagocytes release elastase, an enzyme that damages the elasticity of the alveolar walls.
• What happens when there is not enough elastin in the alveolar walls?

  Alveoli may break down or burst, creating large air spaces in the alveoli, leading to patients becoming weary and breathless.
• what are chemicals in cigarettes


  tar, nicotine, carbon monoxide
• why is tar bad

  Because it contains carcinogens that cause cancer of the mouth and lungs
• why is nicotine bad


  Narrows blood vessels, increasing blood pressure

  Increases heart rate

  This causes blood clots to form in arteries leading to heart attack or stroke
• why is carbon monoxide bad

  Carbon monoxide combines with heamaglobin in red blood cells, meaning they can't carry oxygen around the body
• how does tar effect air passages


  - destroys cilia - causing build up of mucus and potentially leading to bronchitis as the lining of the bronchi become irritated
• how does tar effect alveoli


  - contributes to the breakdown of alveolar epithelial cells - results in thick scar tissue and loss of elastin

  - this creates insufficient SA:Vol ratio allowing less gas exchange

  - reduces efficiency of gas exchange- causes emphysema where lung tissue cannot recoil to expel stale air - results in less fresh air coming in and less oxygen being carried in blood (exercise difficulty)

  - can also build up and form a sticky layer on top of the alveolar cells which can increase the diffusion distance for gas exchange and trap pathogens