Topic 5c - Gas exchange Flashcards
Invertebrates & amphibians use which kind of gas exchange organ?
body surface
Insects use which gas exchange organ for respiration?
tracheae -> directly into cell DO NOT ENTER CAPILLARIES first like other systems
Some invertebrates and salamanders use … for gas exchange?
external gills
Fish use gills for gas exchange. This is called …?
one-way flow
Mammals/terrestrial vertebrates use lungs for gas exchange. This is called …?
two-way airflow
What is a spiracle?
structure on insects that joins to tracheae -> tracheoles -> body cells for gas exchange
Why is countercurrent flow more efficient than co-current flow?
Because it allows for a larger gas exchange surface
What are the 2 means of gas exchange in amphibians?
skin (must be moist)
gills (immatures)/lungs (adults)
Breathing…
inhalation - active contraction of muscles
exhalation - primarily passive
What controls breathing?
- impulses from resp. centre
What is breathing primarily regulated by?
CO2 levels in the blood (high CO2 levels stimulate breathing)
What is the backup control?
control via O2 receptors
Where are the breathing control centres? How does the breathing reflex work in response to changing [CO2] & [O2]?
Nerve impulses from heart relay changes in [CO2] & [O2] -> breathing control centres (pons & medulla oblongata) -> nerve impulses trigger contraction of muscles (incl. diaphragm)
