Ventilation Part 2

Question 1

Does the diaphragm contract or relax in inhalation and what effect does this have on the ribcage?

Answer 1

-contracts (moves down)
-moves in the superior direction

Question 2

Does the diaphragm contract or relax in exhalation and what effect does this have on the ribcage?

Answer 2

-relaxes (moves up)
-moves in the inferior direction

Question 3

What is the bony plate that protects the gills of the fish called?

Answer 3

Operculum

Question 4

What do the gills consist of?

Answer 4

-gill filaments
-gill arches
-lamellae

Question 5

What are the two cavities involved in fish ventilation?

Answer 5

-buccal cavity
-opercular cavity

Question 6

-What type of current helps for an efficient gas exchange in fish?
-explain how it is effecient

Answer 6

-counter current, a description that involves two fluids(blood and water) flowing in the opposite directions
-the two fluids flowing in opposite directions allows for a difference in concentration gradient of oxygen to be present across the entire area of the gills therefore oxygen and diffuse through the entire area

Question 7

Why is countercurrent better than co-current?

Answer 7

-whilst co-current has a steeper concentrations gradient, it reaches equilibrium half way through the area
-counter current has a less steep concentration gradient that is maintained through the whole area of the gills so oxygen can diffuse through the whole area

Question 8

Describe how fish ventilates

Answer 8

-the fish lowers it’s jaw, increasing the volume of the buccal cavity and letting water in
- the fish brings it’s jaw up, decreasing volume of the buccal cavity bringing water into the opercular cavity
-the operculum moves outward increasing volume and decreasing pressure of the opercular cavity
-allowing water to flow through the gills