3.1 Exchange Surfaces and Breathing Flashcards
Exchange surface
A specialised area that is adapted to make it easier for molecules to cross from one side of the surface to the other
Tissues
A group of similar specialised cells working together to perform a common function
Gaseous exchange
The movement of gases by diffusion between an organism and its environment across a barrier eg. Alveoli
Expiration - 6 steps
1) diaphragm relaxes, expands moves ⬆️
2) external ICM relax, ribs move in
3) internal ICM contract - push air out
4) decreases vol. inside thorax + lungs
5) induces pressure inside lungs to above atmospheric pressure
6) air moves out of lungs down pressure grad
Inspiration - 5 steps
1) diaphragm contracts flattens moves ⬇️
2) ext. ICM contract, ribs ⬆️+out
3) increases vol. inside thorax + lungs
4) reduces pressure below atmospheric pressure
5) air moves down pressure grad.
Tissues found in bronchioles
Ciliates epithelium
Goblet cells (large bronchi only)
Smooth muscle
Elastic fibres
Tissues in bronchi
Cartilage Ciliates epithelium Goblet cells Smooth muscle Elastic fibres
Tissues in trachea
C shaped cartilage Ciliates epithelium Goblet cells Smooth muscle Elastic fibres
Tissues in alveoli
Elastic fibres Squamous epithelium (cells of wall)
Role of blood vessels
Supply lung tissue with oxygen for aerobic respiration
Role of elastic fibres
Do not contract / relax
Stretch when smooth muscle contracts
Recoil when smooth muscle relax to help airway return to its original shape
Role of smooth muscle
Constrict airways when it contracts
Reduces flow of air to reduce harmful substances that enter
Role of goblet cells
Secrete mucus
Traps bacteria and dust
Removed from lungs to reduce infection risk
Role of ciliates epithelium
Waft to and fro
push mucus up to the top of the trachea
removed from lungs
Role of c shaped cartilage
Keep airways open
Prevent collapse due to low pressure during inspiration
Allow neck flexibility
Swallowing with oesophagus
Tidal volume
Volume of air moved in and out of the lungs with each breath at rest
Expiration reserve volume
Volume of air that can be breathed out above the normal tidal volume
Vital capacity
Largest volume of air that can be moved in and out of the lungs in one breath
Residual volume
Volume of air that always remains in the lungs even after biggest possible exhalation
Inspiratory reserve volume
Volume of air that can be breathed in above normal tidal volume
How many gills do fish have
5 pairs
Operculum
Bony plate that covers the gills
Gill filaments
2 Gill filaments (aka primary lamellae) makes up one Gill
Secondary lamellae
Filaments are folded into secondary lamellae (aka Gill plates)
