6.4.3
Lung Disease
Overview of Lung Disease
Overview of Lung Disease
Lung disease affects the ability of the lungs to exchange gases over their surface. This can be direct tissue damage or a reduced ability to ventilate.


Diseases
Diseases
- Lung diseases can cause issues with gas exchange and ventilation. Diseases include:
- Asthma.
- Pulmonary fibrosis.
- Tuberculosis.
- Emphysema.


Causes
Causes
- Gas exchange problems are caused when the exchange system is damaged.
- The causes of these problems can include:
- Decreased surface area.
- Increased diffusion distance.
- Decreased concentration gradient.


Symptoms
Symptoms
- Symptoms of gas exchange or ventilation issues include:
- Coughing mucus or blood.
- Faster, shallower breathing.
- Blood oxygen saturation readings below 90%.
- Fatigue.
Effects of Lung Disease
Effects of Lung Disease
Different lung diseases have different effects on gas exchange and/or ventilation in the respiratory system. These effects include:


Emphysema
Emphysema
- Emphysema is caused by smoking or air pollution.
- Dirt and bacteria become trapped in the alveoli which damages the alveoli walls.
- The alveoli provide a large surface area for gas exchange.
- Damage to the walls decreases the surface area and rate of gas exchange declines.


Asthma
Asthma
- Asthma increases the production of mucus by the epithelial cells.
- The increased mucus increases the length of the diffusion distance.
- The greater diffusion distance decreases the rate of gas exchange.
- An asthma attack also causes the smooth muscle in the bronchioles to contract. This makes it difficult to breathe.


Tuberculosis
Tuberculosis
- Tuberculosis bacteria can infect the lungs, damaging the lung tissue.
- The cells of the immune system can also damage the lungs.
- The damaged lungs lead to a decreased tidal volume.
1Cell Biology
1.1Introduction to Cells
1.2Ultrastructure of Cells
1.3Membrane Structure
1.4Membrane Transport
1.5The Origin of Cells
2Molecular Biology
2.1Water
2.2Carbohydrates & Lipids
2.3Proteins
2.4Enzymes
2.5Structure of DNA & RNA
2.6DNA Replication, Transcription & Translation
2.7Cell Respiration
2.8Photosynthesis
3Genetics
3.1Genes
3.2Chromosomes
3.3Meiosis
3.4Inheritance
3.5Genetic Modification & Biotechnology
4Ecology
4.1Species, Communities & Ecosytems
4.3Carbon Cycle
5Evolution & Biodiversity
5.1Evidence for Evolution
5.2Natural Selection
5.3Classification of Biodiversity
6Human Physiology
6.1Digestion & Absorption
6.2The Blood System
6.3Defence Against Infectious Disease
6.5Neurons & Synapses
7AHL: Nucleic Acids
7.1DNA Structure & Replication
7.2Transcription & Gene Expression
8AHL: Metabolism, Cell Respiration & Photosynthesis
8.1Metabolism
8.2Cell Respiration
9AHL: Plant Biology
9.1Transport in the Xylem of Plants
9.2Transport in the Phloem of Plants
9.3Growth in Plants
10AHL: Genetics & Evolution
10.1Meiosis
10.2Inheritance
10.2.1Linked Genes
10.2.2Sex-Linked Genes
10.2.3Non-Nuclear Inheritance
10.2.4Chi-Squared Test
10.2.5End of Topic Quiz - Inheritance
10.2.6IB Multiple Choice - Non-Mendelian Genetics
10.2.7Introduction to Non-Mendelian Inheritance
10.2.8Extended Response - Inheritance
10.2.9Grade 4-5 (Scientific Practices) - Inheritance
11AHL: Animal Physiology
11.1Antibody Production & Vaccination
11.3The Kidney & Osmoregulation
Jump to other topics
1Cell Biology
1.1Introduction to Cells
1.2Ultrastructure of Cells
1.3Membrane Structure
1.4Membrane Transport
1.5The Origin of Cells
2Molecular Biology
2.1Water
2.2Carbohydrates & Lipids
2.3Proteins
2.4Enzymes
2.5Structure of DNA & RNA
2.6DNA Replication, Transcription & Translation
2.7Cell Respiration
2.8Photosynthesis
3Genetics
3.1Genes
3.2Chromosomes
3.3Meiosis
3.4Inheritance
3.5Genetic Modification & Biotechnology
4Ecology
4.1Species, Communities & Ecosytems
4.3Carbon Cycle
5Evolution & Biodiversity
5.1Evidence for Evolution
5.2Natural Selection
5.3Classification of Biodiversity
6Human Physiology
6.1Digestion & Absorption
6.2The Blood System
6.3Defence Against Infectious Disease
6.5Neurons & Synapses
7AHL: Nucleic Acids
7.1DNA Structure & Replication
7.2Transcription & Gene Expression
8AHL: Metabolism, Cell Respiration & Photosynthesis
8.1Metabolism
8.2Cell Respiration
9AHL: Plant Biology
9.1Transport in the Xylem of Plants
9.2Transport in the Phloem of Plants
9.3Growth in Plants
10AHL: Genetics & Evolution
10.1Meiosis
10.2Inheritance
10.2.1Linked Genes
10.2.2Sex-Linked Genes
10.2.3Non-Nuclear Inheritance
10.2.4Chi-Squared Test
10.2.5End of Topic Quiz - Inheritance
10.2.6IB Multiple Choice - Non-Mendelian Genetics
10.2.7Introduction to Non-Mendelian Inheritance
10.2.8Extended Response - Inheritance
10.2.9Grade 4-5 (Scientific Practices) - Inheritance
11AHL: Animal Physiology
11.1Antibody Production & Vaccination
11.3The Kidney & Osmoregulation
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