Zusammenfassung der Ressource
Gas Exchange
- Size & Surface Area
- Smaller animals
- High surface area
- Low volume
- Multicellular organisms
- Need exchange organs
- Diffusion too slow
- Affects heat exchange
- Depends on SA
- Small means it
is harder to
loose heat
- Compact shape
means less SA
- Gas Exchange
- Fish
- Counter-current
- Water & blood flow in
different directions
- Maximises gas
exchange
- Concentration of oxygen in water
always higher than blood
- Filaments
- Increase SA
- Lamellae at right
angle to filaments
- Insects
- Tracheae
- Spiricles
- Pores on surface
- Oxygen travels down concentration gradient
- Humans
- Lungs
- Trachea
- C-shaped cartilidge
- Supports and
stops
collapsing
- Bronchi
- Bronchioles
- Alveoli
- Thin exchange surface
- Short diffusion pathway
- Speeds up rate
- Large SA
- Large number of alveoli
- Surrounded by capillaries
- Maintains concentration gradient
- Inhalation
- Internal relax
- External contract
- Diaphragm contracts
- Flattens
- Exhalation
- External relax
- Internal contract
- Diaphragm relax
- Effects of lung disease
- TB
- Reduces tidal volume
- Gas exchange surface damaged
- Can cause fibrosis
- Fibrosis
- Formation of scar tissue
- Less recoil
- Reduced FEV
- Asthma
- Inflamed airways
- Large amounts of mucus
- FEV reduced
- Emphysema
- Inflammation
- Break down of elastin
- Less recoil