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The respiratory system - Coggle Diagram
The respiratory system
Breathing
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Inhalation/inspiration
- Diaphragm muscle contracts to flattened position
- External intercostal muscles relax, internal intercostal muscles contract
- Ribs and sternum move upwards and outwards
- Thoracic cavity expands and volume increases
- Atmospheric pressure is higher than pressure within lungs
- Air is forced into lungs
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Smoking
Tobacco smoke
Tar
- Contains carcinogenic chemicals which induce uncontrolled division of epithelium
- Blockage in air sacs and reduction in gas exchange efficiency
- Paralyses cilia lining in air passage
- Dust particles trapped in mucus lining in airways cannot be removed
- Pathogens remain in close contact with cells
- Increased risk of infections
Nicotine
- Addictive
- Causes release of hormone adrenaline
- Increases heartbeat and blood pressure
- Makes blood clot easily
- Increased risk of blood clots in blood vessels
Carbon monoxide
- Combines with haemoglobin to form carboxyhaemoglobin
- Reduces oxygen transport efficiency of red blood cells
- Increases rate of fatty deposits on inner arterial wall
- Lumen narrower, increases risk of atherosclerosis
- Damages lining of blood vessels
- Increase risk of blood clotting in arteries (thrombosis)
Diseases associated
Chronic bronchitis
- Epithelium lining the airways , bronchi becomes inflamed
- Excessive mucus secreted by epithelium
- Cilia become paralysed hence mucus and dust particles cannot be removed
- Airways become blocked - breathing difficulties
- Increased risk of lung infections, emphysema
Emphysema
- Long term persistent and violent coughing causes breaking of partition walls between air sacs
- Surfaces area for gaseous exchange decreases
- Lungs become inflated with air and loses elasticity
Lung cancer
- Carcinogens in cigarette smoke cause mutations in lung cells
- May result in uncontrolled division of cells in lungs producing outgrowths or lumps of tissues called tumors
- Smoking also increases cancers of the mouth, pancreas, kidneys and urinary bladder
Respiration
Types
Aerobic respiration
Definition
Complete breakdown of food substances in the presence of oxygen with the release of large amount of energy
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Anaerobic respiration
Definition
The incomplete breakdown of food substances in the absence of oxygen with the release of small amount of energy
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When exercising
- Large amount of energy released for muscular contractions
- Panting to remove carbon dioxide and take in more oxygen
- Heart beats faster and harder so that more oxygen can be brought faster to muscles
- Anaerobic respiration produces lactic acid, causing burning sensation in active muscle cells, muscular pain
After exercising
- Breathing rate continues to be high to repay oxygen debt (oxygen required to convert all lactic acid accumulated back into glucose)
- Lactic acid is transported to the liver, oxidised to release small amount of energy
- Energy is used to convert remaining lactic acid into glucose
Parts
Nose and nostrils
Nasal hairs
Trap dust, foreign particles e.g. bacteria
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Sensory cells in mucous membrane detects harmful chemicals
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Trachea, bronchi, bronchioles
Epithelial cells
Cilia
Sweeps dust particles and bacteria up the bronchi and trachea into pharynx before they are swallowed into oesophagus
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Lungs
Lubricating fluid between pleura allows membrane to glide over each other easily when lungs expand and contract
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