Exchange Surface Flashcards
State the formula for the surface area of a sphere
4πr²
What’s the formula for the Volume of a sphere
V = ⁴⁄₃πr³
3 reasons diffusions to slow for multicellular organisms
- large diffusion distance
- low surface area:volume ratio
- high metabolic rate
name 3 special features found in exchange surfaces
- large surface area
- thin
- good blood supply and/or ventilation
what are cillia
Hair like structures on the surface of epithelial cells lining airways. Beat mucus moving dust away fro alveoli
Name 2 methods of gas movement in insects
1) diffusion, conc gradient (main method)
2) mass transport
whats counter-current exchange
system in which blood flows in 1 direction + water flows in opposite direction across the gills of a fish
Each Alveolus is made from a single layer of thin flat cells called?
Alveolar epithelium
Where are elastic fibers found
- Walls of trachea
- Bronchi
- Bronchioles
- Alveoli
Where is smooth muscle found
- Walls of trachea
- Bronchi
- Bronchioles
Where is cartillage found
- Walls of trachea
- Bronchi
Elastic fibres help
Help breathing:
- breathe in fibres stretch
- breathe out fibres recoil pushing air out.
Smooth muscles help
Allows their diameter to be controlled:
during exercise smooth muscle relaxes, making tubes wider, less resistance to airflow.
Cartilage helps
strong but flexible:
support trachea and bronchi, stops collapsing
During inspiration:
- external intercostal muscle + diaphragm muscles=
- ribcage moves=
- diaphragm=
- volume of thorax=
- lung pressure=
- causes air to flow=
- contract
- upwards and outwards
- flatten
- increases
- decreases
- into lungs
