Zusammenfassung der Ressource
Human Gas Exchange
- Gas Exchange System
- INSIDE BODY BECAUSE...
- Air not dense
enough to support
or protect delicate
structures
- Would quickly dry out
if outside the body
- Gas exchange
occurs at the Alveoli,
which is well adapted
for exchange:
- Large surface area to
volume ratio
- Thin walls
- Constant concentration
gradient due to moving
mediums
- Breathing
- INSPIRATION
- Breathing in
- Active process
- 1. External intercostal muscles
contract and internal intercostal
muscles relax. Ribcage moves up and out
- 2. Diaphragm contracts and flattens
- 3. Volume in thorax increased and pressure reduced
- 4. Air rushes in
- EXPIRATION
- Breathing out
- Largely passive
process
- More muscle
contraction
when forcefully
breathing e.g.
during
exercise
- 1. Internal intercostal muscles
contract and external intercostal
muscles relax. This moves the
ribcage down
- 2. The diaphragm relaxes, curving up
- 3. The volume of the thorax is reduced and
the pressure increased
- 4. Air rushes out
- PULMONARY
VENTILATION