3946751
Flashcards by maddygoldie, updated more than 1 year ago
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Created by maddygoldie
over 5 years ago
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Description
| Question | Answer |
| Pharynx | Air passes through |
| Larynx | - Voice organ - Vocal chords vibrate as air passes through |
| Trachea | Carries air to and from lungs |
| Ribs | Form framework for chest |
| Intercostal muscles | - Muscles between ribs - Move rib cage to increase or decrease volume |
| Lungs | - Occupy all chest cavity - Covered in pleural membrane - Pleural fluid between 2 layers holds lungs against inside of chest |
| Diaphragm | - Muscle -> separates chest from abdomen - Flattens or bulges to increase or decrease volume of chest cavity |
| Nasal cavity | - Projections -> increase internal SA - Filters, warms and moistens air - Contains smell receptors - Resonating chamber for speech sounds - Hairs and mucus trap dust |
| Epiglottis | - Flap of tissue -> closes off trachea during swallowing so food/liquid can't enter lungs |
| Bronchi | - Branch from trachea - Divide into secondary and tertiary bronchi |
| Bronchioles | - Fine tubes, walls of smooth muscle - Finest end in groups of air sacs called alveoli |
| Alveoli | - Tiny air sacs - make up most of the lung - Occur in clusters - Very thin walls, well supplied with blood capillaries for gas exchange |
| What are the two things cells need? | - Oxygen for respiration - To remove carbon dioxide and wastes |
| What happens in the lungs and tissues? | - Lungs -> oxygen is taken from air into blood, blood transports oxygen to cells in all tissues - Tissue -> blood picks up CO2 and takes to lungs to pass into air |
| How are lungs suited to gas exchange? | - Alveoli give lungs huge internal SA - Each alveolus is well supplied with blood vessels - continuous blood supply maintains concentration gradient - Alveolus wall is thin - Lungs positioned deep inside chest - Lung volume can be changed by movement of respiratory muscles |
| What is inspiration? | - Process of taking air into lungs - Air inside lungs must be less than atmospheric pressure outside body - To decrease pressure in lungs, the volume of the lungs must increase |
| How is the volume increased in inspiration? | 1. Diaphragm contracts and flattens 2. Intercostal muscles contract, moving ribcage out and up and increasing volume 3. This causes lungs to expand 4. If volume increased, pressure decreased 5. Air flows from high pressure to low pressure. Air will flow from outside to inside lungs. |
| What is expiration? | - Removing air from lungs - To increase pressure inside lungs, volume of lungs must decrease - High pressure in lungs for air to move out |
| How is the volume of the lungs decreased during expiration? | 1. Diaphragm relaxes and bulges 2. Intercostal muscles relax moving ribcage in and down 3. Decreases volume in chest cavity, increasing pressure 4. Air wants to flow out of lungs |
| For gas exchange to occur, what must be present? | - Concentration gradient - Difference in concentration of oxygen and CO2 in alveoli and blood surrounding - Maintained by constant flow of blood through capillaries and movement of air in and out of lungs as we breathe |
| Process of gas exchange (basic) | 1. Blood in capillaries (from body) surrounding alveoli is low in O2, high CO2 2. Air in alveoli (from outside) is high in O2 and low CO2 3. O2 diffuses through membrane and capillaries into blood 4. CO2 diffuses out of blood, into air in alveolus |
| What makes gas exchange easy? | - Wall of alveoli and capillaries are one cell thick - Inside alveolus is lined with film of moisture |
| Emphysema - Cause - What happens? | - Cause - long term exposure to irritating particles in air taken into lungs -> smokers, workers with dust, cities - Particles damage alveoli and reduce SA of lungs, difficult ventilating lungs and requires voluntary effort |
| Lung cancer - Cause - What is it? | - Cause - exposure to asbestos fibres and other pollutants (smokers) - Excessive mucus production, cells begin to divide more rapidly accumulating mucus can't be removed, causes rupture of alveoli, cancerous growths develop |
| Pneumonia - What is it? | - Infection of the lungs -> causes inflammation which causes secretion of fluid and mucus in the alveoli, reducing surface area and creating breathing difficulties - Caused by bacteria, viruses, fungi or other organisms |
| Tuberculosis - What is it? - Cause - Spread - Prevent | - Infection by the bacterium, mycobacterium tuberculosis - Spread by highly contagious droplets of moisture (cough, sneeze, spit) - Good hygiene practices prevents spread |
| Asthma - What is it? | - Allergic response to foreign substances that enter the body - Muscles around bronchiole go into spasm (involuntary contraction, narrow air passages, produce mucus) -> difficulty breathing - Gas exchange impaired, blood doesn't carry usual amount O2 |