Respiratory System Flashcards
Describe the process of “Inspiration”
- Diaphragm contracts; becomes flat.
- External intercostals contract; rib cage expands.
- Vol of thoracic cavity increases.
- Pressure in lungs decreases.
- Air rushes in.
Describe the process of “Expiration”
- Internal intercostals contract; rib cage moves inwards and downwards.
- Abdominal muscles contract; stomach/liver push diaphragm back so it’s domed again.
- Vol of thoracic cavity decreases.
- Pressure increases.
- Air rushes out.
- What gas diffuses into the alveoli and exits the lungs?
2. What gas diffuses out of the alveoli and enters the blood?
- Carbon Dioxide
2. Oxygen
What are the 7 values for inhalation/exhalation of the lungs?
- Total Lung Capacity - max air that can fill lungs
- Tidal Volume - normal amount of air displaced between inhalation & exhalation
- Vital Capacity - max air that can be exhaled after maximum inhalation
- Residual Volume - amount of air remaining in the lungs after exhalation
- Inspiratory Reserve Volume - how much air can be inhaled after normal inhalation
- Expiratory Reserve Volume - how much air can be exhaled after normal exhalation
- Inspiratory Capacity - amount of air taken in during a deep breath
- How does emphysema affect the alveoli?
2. How does this impact gas exchange?
- Emphysema causes the cells of the alveoli to break down and die when the alveoli shrink to push air out of the lungs.
- Less surface area for diffusion, and air would escape instead of diffusing into the blood directly.
Describe the role of alveoli in the lungs.
The alveoli in the lungs are where oxygen & carbon dioxide are exchanged to and from the bloodstream.
Describe the role of the intercostal muscles and the diaphragm during inspiration and expiration.
- The intercostal muscles act upon the ribs when inhaling to expand up and out, to allow the lungs to expand and fill with air; when exhaling, these muscles contract down and in as air moves out of the lungs.
- The diaphragm expands down and out when inhaling. This creates a vacuum in the lungs to draw air in. During exhalation, the diaphragm contracts up and in to push air out.
Describe the role of each in the trachea and bronchi)
- Ciliated epithelial cells
- Goblet cells
- Smooth muscle
- Cartilage
- Cilia-covered cells which help to move substances or fluids, usually to make them exit the body during a sneeze.
- To secrete mucus in order to protect the mucus membranes where they’re found.
- Involuntarily moving muscles. Helps the lungs regulate airflow.
- Support for the trachea whilst still allowing it to be flexible.
Explain why each of these features in the alveoli are essential)
- One layer of squamous epithelial cells
- Elastin in the walls
- Large surface area
- Moist lining
- Surfactant
- Extensive capillary network
- So that the diffusion pathway remains short, allowing for quicker diffusion of gases in/out of the lungs.
- Important for the elasticity and extensibility of the lungs during inhalation & exhalation.
- A larger surface area means more diffusion happening.
- Oxygen and Carbon Dioxide gases can only diffuse over the lungs surface if dissolved in water, so the surface must be moist.
- Surfactant enables the lungs to expand without as much force as otherwise, thus making it easier to breath.
- To allow for more Oxygen to enter the blood, and more Carbon Dioxide to exit, in conjunction with larger SA.
Describe the structure of pleural membranes.
Membrane which folds back on itself to form a double-layer, which encloses some pleural fluid.
What does a peak flow meter measure?
It measures how well air moves out of the lungs. It tests those with asthma.
Describe how exercise affects:
- Tidal volume
- Breathing rate
- Oxygen consumption
- Respiratory minute ventilation
4.
