Anatomy + Function of Fish Gill

Question 1

Why is the gill the most efficient gas exchange organ in vertebrates?

Answer 1

• low O2 available
• costly to breathe
• has to be

Question 2

What is the buccal cavity?

Answer 2

• mouth

Question 3

How does water move through the fish?

Answer 3

• mouth/buccal cavity –> gills –> opercular cavity –> operculum –> opening exit

Question 4

What does water pass from BC to OP?

Answer 4

• pairs of filaments

Question 5

What is the lamella?

Answer 5

• respiratory surface
• water flows through

Question 6

The SA of lamella is ___. This is because:

Answer 6

• large because there are a lot of them

Question 7

The distance of travel in lamella is ____. This is because:

Answer 7

• small because there are thin epithelium and endothelium

Question 8

Epithelium is on the ____ of the lamella and endothelium is on the ___.

Answer 8

• outside vs inside

Question 9

What are Pavement cells?

Answer 9

• flat cells

Question 10

What are pillar cells?

Answer 10

• endothelial-like cells
• thin flanges

Question 11

What is the function of pillar cells? (4)

Answer 11

• line blood space
• maintain integrity
• contractile (decrease blood flow when contracted)
  –> regulate blood flow

Question 12

How is non-respiratory blood supplied to the gills?

Answer 12

• via venolymphatic vessels and basal blood vessels

Question 13

What do venolymphatic vessels do?

Answer 13

• supply nutrients
• take away waste

Question 14

Where is non-respiratory blood?

Answer 14

• within filament

Question 15

What do basal blood vessels do?

Answer 15

• shunt/bypass blood from gas exchange (far from water)

Question 16

Where does lamellar blood flow control go?

Answer 16

• to lamella

Question 17

What is O2 sensed by during lamellar blood flow control?

Answer 17

• chemoreceptors on the 1st arch

Question 18

What is the 1st arch?

Answer 18

• neuroepithelial cells
• gas sensing

Question 19

What % is lamellar profusion normoxia? why?

Answer 19

• 58%
• not full capacity when O2 levels normal

Question 20

What % is lamellar profusion at hypoxia?

Answer 20

• 70%

Question 21

in regards to lamellar microcirculation, what do cholinergic receive?

Answer 21

• acetylcholine

Question 22

in regards to lamellar microcirculation, what NS are cholinergic receptors part of?

Answer 22

• parasympathetic (res/digest)

Question 23

What is vasoconstriction? What receptors do this?

Answer 23

• blood vessel constriction (blood flow)
• (-) 43% flow
• cholinogetic

Question 24

in regards to lamellar microcirculation, what do adrenergic receptors recieve?

Answer 24

• epinephrine (adrenaline)

Question 25

What NS do adrenergic receptors stimulate?

Answer 25

- sympathetic (fight/flight)

Question 26

What is vasodilation? what receptors cause this?

Answer 26

- vessel dilation - increase blood flow (+70%) - adrenergic

Question 27

What does endothelin do?

Answer 27

- contracts lamellar pillar cells (decreases blood flow)

Question 28

what factor is endothelin?

Answer 28

- autocrine/paracrine