Lecture 7 - 2.0

Question 1

What are the Requirements for Respiration (Gas Exchange) (4):

Answer 1

1. Requires a surface between the environment and respiratory organs
2. Transport of gasses in blood to capillaries
3. Exchange surface between capillaries and tissues
4. Respiratory and circulatory systems work together

Question 2

What Does Diffusion Need to Take Place (3):

Answer 2

1. Largs surface area
2. Thin, moist barrier
3. Effective ventilation (gradient)

Question 3

Fish Gills Basic Structures (4):

Answer 3

1. Gill arches
2. Gill rakers
3. Gill filaments
4. Secondary lamellae

Question 4

What are Gill Arches in a Fish’s Gills:

Answer 4

They are composed of gill rakers (debris filters) on the pharyngeal edge with gill filaments (respiration) on the distal edge

Question 5

What Do Gill Rakers do in Fish Gills:

Answer 5

Debris filters

Question 6

What do Gill Filaments do in Fish Gills:

Answer 6

Respiration

Question 7

What is the Secondary Lamellae in Fish Gills:

Answer 7

Further increase surface area on gill filaments

Question 8

Aspects of Internal Gills (Pouched Gills) (3):

Answer 8

1. No gill covering
2. Present in lamprey
3. Tidal Ventilation

Question 9

What is Tidal Ventilation in Pouched Gills:

Answer 9

Puts water through the gills by muscle compression and relaxation of branchial apparatus

Question 10

Aspects of Internal Gills (Septa Gills) (3):

Answer 10

1. Dual pump ventilation pushes water unidirectionally over the gills
2. Water enters mouth, pumped over gills then out through external gill openings
3. Gill arches separated by interbranchial septa

Question 11

What are Spiracles (2):

Answer 11

1. A top-opening used to ventilate gills while buried in the sand
2. Some use this for air-breathing

Question 12

Aspects of Internal Gills (Opercular Gills) (3):

Answer 12

1. Dual pump ventilation pushes water unidirectionally over the gills
2. Water enters mouth, pumped over gills then out through external gill openings
3. Gill arches protected by bony operculum (which is somewhat of a covering)

Question 13

How Does Dual Pump Gill Ventilation Work:

Answer 13

Buccal and opercular components act like a two-stroke pump with alternating cycles of negative and positive pressure

Question 14

What are Lungs in Fish:

Answer 14

Paired structures ventral to the gut

Question 15

What are Swim Bladders in Fish (3):

Answer 15

1. Single elongated sac dorsal to the gut
2. Used for bouyancy
3. Sometimes also helps with respiration and sound production and reception

Question 16

How does a Physostomous Swim Bladder Get Filled:

Answer 16

By gulping air into the digestive tract (can also be used as respiratory gas bladder)

Question 17

How does a Physoclistous Gas Bladder get Filled:

Answer 17

Filled by gas gland, empties at oval window

Question 18

Fish Circulation: Basic Structure (2 Components)

Answer 18

1. Four-chambered heart in a straight line
2. Single-circuit system

Question 19

Components of the Four-Chambered heart in Fish (2):

Answer 19

• 2 True chambers: artium and ventricle
• 2 accessory chambers: sinus venosus, conus (or bulbus) arteriosus

Question 20

What Doe the Single-Circuit System do in Fish:

Answer 20

Pumps deoxygenated blood through heart in one direction

Question 21

What is the Conus Arteriosus and What Does it Do (In Sharks)?

Answer 21

Is large, muscular and active as pumping organ

Question 22

Variations on Single-Circuit Pump Pattern (Teleosts) (2):

Answer 22

1. Highly elastic bulbous arteriosus in place of conus
2. Keeps consistent flow to arches despite pressure generated by beating heart

Question 23

Variations on Single-Circuit Pump Pattern (Lungfishes) (3):

Answer 23

1. Partially divided atrium and ventricle (septa)
2. Division extends into the conus by spiral fold valve
3. Greatly reduces mixing of oxygenated and deoxygenated blood