3.1 Exchange surfaces and breathing Flashcards
A big animal has a …….. SA:V
small
A small animal has a ……… SA:V
big
What 3 factors affect the need for an exchange system?
size
SA:V
level of activity
What are features of a good exchange surface?
large SA:V
a thin barrier
a good blood supply
What are the 4 main parts to the mammalian gaseous exchange system?
Trachea, bronchi, bronchioles, and alveoli
How does the mammalian gaseous exchange system have a large SA:V?
millions of alveoli
How is the diffusion distance shortened in the mammalian gaseous exchange system?
Squamous epithelial cells are thin and flat
What fibers do alveoli have?
Elastic fibres
What do the trachea, bronchi and bronchioles have in common?
goblet cells
How are the trachea and bronchi similar in structure?
cartilage (C shaped in trachea)
What structure do bronchioles have?
smooth muscle and elastic fibres
Why is it useful for smooth muscle to contract or relax?
If there is a harmful substance, it can contract
What should you check before using a spirometer?
subject does not have asthma
fresh soda lime
no leaks
mouthpiece sterilised
water chamber not overfilled
What is the vital capacity?
The volume of air that can be moved by the lungs in one breath (av. 2.5-5.0 dm^3)
What is the residual volume?
The volume left in the lungs after forced expiration approx. 1.5 dm^3
What is the tidal volume?
The volume moved in and out with each breath (usually at rest) e.g 0.5 dm^3
How are fish gas exchange surfaces specialised?
The gills have lots of lamellae to increase surface area
Countercurrent flow
What is the process of ventilation in a fish?
Lower the buccal cavity to increase volume and water rushes in
Mouth closes and buccal cavity raised to push water over the gills and out
What is the pore called on the body of an insect?
Spiracle
What is the fluid called at the end of tracheoles?
tracheal fluid
What happens to the tracheal fluid when the insect is active?
The fluid moves out of the tracheole to increase the surface area of gas diffusion into cells
What are the main features of insect ventilation?
an air sac that can contract to push air around the body
wing movement can force air around the body
abdomen movement can force air around the body
