Chapter 11 Part 2

Question 1

Describe opercular gills in teleosts

Answer 1

o structures in Teleost and Sarcopterygians
o Operculum: bony flap, singular opening (near gills, called opercular gills)
o Structure:
▪ Mouth, branchial bar, pharynx, gill filaments, operculum, esophagus

Question 2

Gill ventilation in teleosts

Answer 2

Water travels in through oral valve when fish inhaling, Lowering of buccal/opercular cavity, Increase internal size and sucks water in across gills

Mouth closes, Opercular cavity lowers(lower pressure) and buccal cavity heightens (higher pressure)

Opercular cavity opens , Both cavity increase in height

Cycle begins again

Question 3

Internal gills in amphibians

Answer 3

o Aquatic amphibians: pharyngeal slits often persist with internal gills

Question 4

External gills in amphibians

Answer 4

o Feathery external gills are sometimes present as well, but seen in few species
o Example: axolotl

Question 5

Direct development in amphibians

Answer 5

▪ all development undergoes in egg, no tadpole outside egg; hatches as mini-version of adult
▪ - Modified tail allows breathing/air travel

Question 6

Swim bladder: function and who has it

Answer 6

• Swim bladder outgrowth of gut tube
• Swim bladder found in bony fish, octerpygians, sarcopterygians

o Both types adjust the buoyancy of the fish to varying water depth; the swim bladder is a closed bag of gases called a physoclistous swim bladder ; Gas secretion occurs directly across the walls of the bladder

Question 7

difference between physostomous and physoclistous swim bladders

Answer 7

o Physostomous –> Primitive teleosts: the swim bladder is physostomous, retaining its connection to the digestive tract via the pneumatic duct
Physocilistous –> Advanced teleosts: connection lost;

Question 8

Function of the gas gland

Answer 8

Some swim bladders have special gas glands from which gas from the blood is released into the bladder

In the gas gland, blood vessels form a countercurrent capillary arrangement, the rete mirabile

Incoming arterial and outgoing venous capillaries within this rete lie next to one another in the gas gland

(Muscular sphincter to open and close; Hemoglobin going past gas gland drops off oxygen; Oxygen being regulated through sphincter)

Question 9

FIrst evidence of a swim bladder

Answer 9

Bothriolepsis, placoderm(first jawed vertebrate, gnathostome)

Question 10

Pathway of lung evolution:

Answer 10

Sturgeons: swim bladders originate from the stomach

Primitive teleosts: originate from the esophagus (may be of independent origin)

Polypteriformes: paired lungs open through a common muscular glottis into the right floor of the pharynx
· Left lung is reduced, the right one long
· The epithelial lining of both is smooth

Question 11

Lungs in actinopterygians and sarcopterygians/tetrapods

Answer 11

In Actinopterygians: lungs developed first, became modified as swim bladders, moved to dorsal gas bladder

▪ Ventral lungs evolved in the common ancestor to actinopterygians and sarcopterygians
▪ Swim bladders in actinopterygians may have evolved independently, or they may have been modified from earlier lungs

Question 12

Who do not have ventral paired lungs

Answer 12

Not found in agnathans, chrondrichthyans, most placoderms

Question 13

What are faveoli in lungfish lungs?

Answer 13

o The lung is subdivided internally, forming small compartments, or faveoli
o Faveoli are most numerous in the anterior part of the lung

Question 14

Weberian ossicles

Answer 14

carry vibrations to sound detectors within the sacculus and lagena

Part on ribcage in fish with swim bladder, travels to sacculus(internal ear)

Question 15

Cutaneous respiration

Answer 15

the process where animals exchange gases (oxygen and carbon dioxide) directly through their skin

Question 16

In which vertebrate group is cutaneous respiration most common?

Answer 16

o Amphibians, like frogs and salamanders
o Usually best for organisms in low oxygen environment

Question 17

Name two examples of cutaneous respiration

Answer 17

Freshwater eels: breather through skin, since the places they live are low oxygen environments

Lake Titicaca frog: Freshwater at high altitude will create low air available

Question 18

Describe gas exchange in sea snakes and sea kraits

Answer 18

• Nonpulmonary reptiles
• Cutaneous
• Sea snakes can supplement up to 30% of their oxygen intake via cutaneous respiration across the skin on their sides and back
• Primarily aquatic

Question 19

Describe gas exchange in Chinese soft-shelled turtle

Answer 19

• has buccopharyngeal region
• includes structures like villiform processes and rhythmic pharyngeal movements that facilitate gas exchange and urea excretion through the mouth, especially when the turtle is submerged in water

Question 20

Name two species that breathe through cloaca

Answer 20

• murray river turtle
• fitzroy river turtle

Question 21

Respiration in modern amphibians

Answer 21

• skin major respiratory organ; exclusive in others

Question 22

How does gas exchange occur across egg shells?

Answer 22

Chorioallantoic membrane

Question 23

Chorioallantoic membrane

Answer 23

found in bird and reptile embryos, is essential for gas exchange, nutrient absorption, and waste elimination. It combines the chorion and allantois membranes, allowing efficient transfer of oxygen and carbon dioxide, facilitating nutrient uptake, and managing waste products like uric acid

Breaks through the internal shell membrane (starts breathing by using the internal air cell in the egg)
▪ Pipping: bird trying to crack open egg
▪ Pipping muscle In the back of the neck