Journal 1/29/14

1. Journal 1/29/14 Tell me everything you know about brains. Objective Tonight’s Homework To learn how gills and wings specifically function Get vocab definitions for the Special Designs page

2. Special Designs Wings are amazingly complicated things. It took men hundreds of years to figure out flight and they were trying intentionally. Bird wings are both better designed and more efficient than anything we can create. We’ll start by looking at the different feather types. There are 4 main varieties. Quill Contour Filoplume Down

3. Special Designs Quill Feathers These are the large feathers we normally think of when looking at a bird. They’re usually shaped specifically to aid in flight. They’re both strong and light. If a bird loses one, it will lose the exact same one from the other wingas well. This keepsthe birdbalancedfor flight.

4. Special Designs Contour Feathers These are the feathers that cover the majority of the bird’s body. If you look closely at a contour feather, you’ll see hundreds of interlocking barbs, like Velcro. This keeps the feather rigid and strong, but still light. Birds use natural oils to keep the feathers strong.

5. Special Designs Filoplume Feathers These feathers are more rare. Many birds don’t have them. They usually grow in the same places as contour feathers. It’s thought that they help in giving the bird feedback on how it needs to adjust its wings to fly.

6. Special Designs Down Feathers Down feathers don’t have interlocking barbs. Instead, they move freely. Most birds have down. These feathers lie under contour feathers and create a layer that keeps the bird insulated and warm.

7. Special Designs Gills are also designed in an amazingly specific way. Water has 26 times less oxygen in it than air. This means fish have to have a very efficient way of getting that oxygen or they’ll die. In most fish, the gill sits behind the head. Fish get water to the gills by 2 ways: 1) Swimming through the water with their mouth open and the flap leading to the gills open. 2) Gulping water into the mouth, then pushing it into the area with gills.

8. Special Designs The picture below shows how this works. The gill arch contains major blood vessels for the fish. Gill filaments split off from this, providing a ton of surface area. As water flows over a filament lots of tiny blood vessels pull in the oxygen in the water. This then goes out to the rest of the fish’s body.

9. Special Designs If a fish is taken out of water, all these thin filaments stick together and collapse. This is why a fish can’t breathe when out of the water. To keep the gills clean, most fish have something called a “gill raker” right in front of the gill. This is a bony comb-like structure that catches debris and junk and keeps it away from the sensitive gills.

10. Circulatory Systems Special Designs Vocab: <define each> Quill Contour Filoplume Down Gill arch Gill filament Gill raker Wings and gills have been specially designed to give some animals some very efficient ways of surviving. DIAGRAM Special

11. Exit Question #9 What do down feathers do? a) Help a bird with flight b) Cover the bird’s body c) Help the bird adjust to changing flight conditions d) Keep the bird warm e) All of the above f) None of the above