| Where does gas exchange occur in gills ? | The surface of gills |
| Blood flow in the gills | De ox blood flows into each gill filament via afferent arteriole that branches into small capillaries across the lamellae .Oxygen from water diffuses into the capillary along a conc gradient.
Oxygenated blood flows out of the gill filaments via the efferent arteriole. |
| Concurrent mechanism | a current flowing in the opposite direction of the other current
so no equillibrium is reached so they is always a conc gradient |
| Structural adaptations in fish | -small branching capillaries = large surface area
-lamellae are made of single layer ephithelial cells= short difusion pathway
-maintain conc gradient = concurrent mech
- |
| What does a stomata do | Gases diffuse in and out
water enters into guard cells by osmoisis making them turgid to open |
| Structural adaptions of the stomata | -numerous mesophyll cells lining the intercellular air spaces= large surface area
- leaves are thin so short diffusion pathway
-respiration and photosynthesis maintain conc gradient |
| What are spiracles? | Pores running on the side of the body
open and close like valves |
| Insect gas exchange | Spiracles open letting air in
system tubes carry the air to repsiring tubes
large tubes called the trachea branch into small tubes called tracheoles
to the cells |
