Topic 3- Lung disease Flashcards
Give 2 examples of diseases which affect gas exchange
-lung cancer
-COPD
If mutations occur in oncogenes or tumour-suppressor genes of the bronchial epithelial cells, tumours develop. What does this cause?
uncontrolled mitosis which develops into a mass of cells in the lumen of the airways
Why does the tumour become larger?
no method of programmed cell death and survives because it develops its own blood supply (vascularisation)
How does the tumor interfere with normal working of the lungs
such as by squeezing against blood vessels or cancer cells entering into the lymphatic system, where they may develop another tumour
What are the symptoms of lung cancer
coughing up blood, a persistent cough, coughing an increased amount of mucus, back or shoulder pain, wheezing and breathing difficulties and sudden weight loss
What are the symptoms of COPD?
shortness of breath, a chronic or persistent cough, chest tightness, wheezing and difficulty breathing when exercising or during any physical activity
What does COPD stand for
Chronic obstructive pulmonary disease
How does COPD occur?
-When goblet cells in the ciliated epithelium become enlarged they produce more mucus
-This destroys the cilia in the trachea and prevents them from sweeping mucus away from the lungs
-The mucus contains bacteria, dust and other microorganisms and can then block narrow bronchioles, causing coughing, scar tissue and infection
-The infection attracts phagocytes to the lungs and the phagocytes release elastase, an enzyme that damages the elasticity of the alveolar walls
-Without enough elastin, the alveoli break down and may burst. This creates large air spaces in the alveoli, making patients wheezy and breathless. Once the disease progresses, people often need a constant supply of oxygen to stay alive
Why is smoking a risk factor?
Chemicals in cigarettes include:
-Tar – a carcinogen (a substance that causes cancer)
-Nicotine – an addictive substance which narrows blood vessels
-Carbon monoxide – reduces the oxygen-carrying capacity of the blood
What effect does tar have?
-a buildup of mucus
-break down of the walls of the alveoli
- increase the diffusion distance for gas exchange
How should you evaluate data based on lung disease?
-Sample size- larger sample= more reliable
-Individuals in the sample- cannot make generalisations
-Levels of exposure-higher levels = higher risk
-Control group-identify if the control group matches the other groups closely enough
-Statistical significance-try to determine if the differences between groups are sufficiently large and whether any statistical tests have been carried out to test the significance of the results
-The influence of other factors/variables- other factors are out of the researchers control such as Genetics,Secondary exposure to smoking,Other factors that have not been controlled that has an effect on lung health (e.g. exercise)
Correlation does not equal
causation
