A&P - Chapter 36 (Part 1) Flashcards
External respiration (2)
- Pulmonary ventilation
2. Pulmonary gas exchange
Pulmonary ventilation
Air moving in and out of the lungs
- breathing
Pulmonary gas exchange
Exchange of O2 and CO2 between the air in the lungs and the blood
Internal respiration
Exchange of gases between the blood and the cells of the body/systemic tissue
Cellular respiration
The use of oxygen by cells in the process of metabolism
Where does cellular respiration occur?
In the mitochondria
What are the 2 phases of breathing?
- Inspiration
2. Expiration
Inspiration
Movement of air into lungs
Expiration
Movement of air out of lungs
What happens to the lungs during breathing? (2)
- Changes in size and shape of thorax
- caused by respiratory muscles - Cause changes in air pressure within the thoracic cavity and the lungs
What causes air to move in and out of the lungs?
Air pressure differences
What happens to the lungs during inspiration? (2)
- Pressure within the alveoli of the lungs is lower than atmospheric pressure
- Chest cavity enlarges, lungs expand, air rushes in
What happens to the lungs during expiration?
Pressure in the alveoli of the lungs is higher than atmospheric pressure
What are the respiration muscles? (3)
- Diaphragm
- Internal intercostals
- External intercostals
What are the inspiratory muscles?
- Diaphragm
2. External intercostals
What happens to the diaphragm during inspiration? (3)
- Contracts
- Flattens
- Increases height of the chest cavity
What happens to the external intercostals during inspiration? (2)
- Contraction lifts the ribs
2. Increase depth and width of chest cavity
What does the increased size of the chest cavity do?
Reduces pressure within it and the lungs, and air enters the lungs
What happens during normal/quiet expiration (passive process)?
Inspiratory muscles relax so the chest cavity returns to its resting size and shape
What aids in expiration?
Elastic recoil of lung tissues
What muscles are used in forceful expiration?
- Internal intercostals
2. Abdominal muscles
What does reduction in the size of the chest cavity do?
Increase its pressure and air leaves the lungs
What do internal intercostals do during expiration?
Contraction depresses the rib cage
- decreases ‘depth’ of chest cavity
What does abdominal muscle contraction do? (2)
- Abdominal organs push up against diaphragm
2. Decrease the ‘height’ of chest cavity
Tidal volume
Amount of air exhaled after normal inspiration
Expiratory reserve volume
Amount of air that can be forcibly exhaled after a normal expiration
- e.g. after expiring the tidal volume
Internal reserve volume
Amount of air that can be forcibly inhaled after a normal inspiration
Residual volume
Air left in lungs after the most forceful expiration
Vital capacity
Largest amount of air that can be breathed out in one respiration/pulmonary ventilation
What is the formula for vital capacity?
Inspiratory reserve volume + tidal volume + expiratory reserve volume
What is pulmonary volumes and capacities measured with?
A spirometer