gas exhnage in fish

Why do fish have a high metabolic demand

Beduase they are active

What is the gas exchange surface in fish?

gills

Are cartilaginous fish more active or less active than bony fish

Less active

Why do cartilaginous fish need to keep swimming

To maintain ventilation because water must physically pass over gills

What type of flow is in cartilaginous fish

Parallel flow

What type of flow is in bony fish

Counter current flow

What opens to gill slits in cartilaginious fish

Gri

What is an operculum

A flap like structure that covers and protects the gill cavity

What is a gill arch

Bony structure that serves as support and attachment points for gill filaments

What is a gill raker

Projections on the side of the gill arch that help to filter food particles out of the water

What are lamellae

Microscopic projections on the filament surface that further increase its area and are the site of gas exchange

What is the buccal cavity

The interior mouth compartment of the fish

What are gill filaments?

Fleshy projections that occur in pairs along the gill length creating a large surface area for gas exchange

What are the adaptations of the gills

-large sa
-short diffusion pathway
-capillaries in each lamellae
-steep concentration gradient maintained by good blood supply and ventilation

What is the first step for ventilation in fish

-fish opens it mouth
-lowers the buccal cavity floor
-volume increases
-pressure decreases
-water flows into the buccal cavity down a pressure gradient
-operculum is closed

What is the second step for ventilation in fish

-mouth closes
-buccal cavity floor is raised
-decreases the volume of the buccal cavity
-increaces the pressure
-forces water over the gills in the opercular cavity

What is the third step in ventilation in fish

• increaces water in the opercular cavity
  -increaces pressure
  -forces the operculum open
  -water is forced out over the gills
  -operculum valve closes again

What is the characteristic of the conc gradient in counter current

Conc gradient is maintained along the entire length of the lamellla

What is the characteristic of the conc gradient in parallel flow

Equilibrium reaches part way along the length of the lamellae

Where does diffusion occur in counter current

Occurs along the whole length of the lamellae

Where does diffusion occur in parallel flow

Partway along the lamellae

What is the max saturation of blood oxygen in counter current

80

What is the max saturation of blood oxygen in parallel flow

50