Fishes Flashcards
(58 cards)
FLASHBACK: what tare the characteristics unique to chorodates
- notochord
- post-anal tail
- dorsal hollow nerve cord
where are pharyngeal slits located?
on lateral surface of the head
pharyngeal slits seam to be an _______ trait in deuterostomes
ancestral
In vertebrates, pharyngeal tissue is supported by what?
arches
What is the function of the pharyngeal slit?
filter feeding - water goes in and out through these slits
How do vertebrates breathe?
- water comes in though the mouth and passes through the slits
- O2 and CO2 can be exchanged across a respiratory surface = gills
where are the gills located?
between the slits
how are the gills supported?
by the arches
Gill slits =
pharyngeal slits
gill arches =
bars between the slits
where are the gill filaments located?
on the gill arches
how many pairs of gill arches do bony fish have?
four
operculum is a
gill cover
the structure of the gill filament is
a thin, vascularized, high surface area
where does gas exchange occur?
in the capillary beds in the gill filaments
Water and blood in which directions?
opposing
the water comes from the ____ across the filament between the _____
mouth ; lamella
when is efficiency of gas exchange low?
when the inside medium (in this case the blood) flows in the same direction as the outside medium (in this case the water)
Why does blood flow in the opposite direction to water flow?
so that concentration gradients are maintained along the length of the exchange area
the circulatory system of fish is
closed
describe the circulatory system
arteries (away from the heart ) –> arterioles –> capillaries
–> venules (towards the heart) –> veins
how many circuits do fish have?
one.
what circuits do we have?
pulmonary circuit and systemic circuit
pulmonary circuit
heart –> lungs –> heart
