1. Comparative Anatomy Respiratory System
Note Set 10
Chapter 11

2. Respiratory System Gas exchange system Fish- internal gills or lungs
Oxygen and carbon dioxide
Fish- internal gills or lungs
Some amphibians- permanent external gills (perennibranchiate)
Others possess lungs

3. Accessory respiration organs
Amphibian skin
Figure 12.1: Adaptations for cutaneous respiration (hairy frog).

4. Fish Respiratory System
Gills associated with walls of pharyngeal arches
Internal gills
Operculum- flap of skin covering gills
Spiracle- reduced 1st pharyngeal
arch opening
Nonfunctional
Not in higher fish
Figure 12.2: Gills of shark and teleost.

5. Swim Bladder & Lungs Every vertebrate has lung diverticulum
Pneumatic sac
Which came first?
Physoclistous
Esophagus not connected to swim
bladder
Physostomous
Trachea to lungs or pneumatic sac
Figure 12.3: Swim bladders and urodele lungs.

6. Primitive Fish Have Primitive Lung
Lung diverticulum came first
Then pneumatic duct in teleosts
Swim bladder was possibly a secondary modification of lung
Figure 12.4: Evolution of lungs and swim bladders.

7. Swim Bladder Red glands (gas glands)- network of small arteries
Provide oxygen to swim bladder
Figure 12.5: Swim bladder (red) of fish.
Figure 12.6: Rete mirabile in fish, red indicates high oxygen concentration.

8. Swim Bladder (cont.) Weberian ossicles
Swim bladder may act as sound chamber
Figure 12.7: Weberian apparatus for transmitting swim bladder vibrations to ear.
Figure 12.8: Weberian ossicles.

9. Tetrapod Lungs
Diaphragmatic muscles pull the liver posteriorly via an attachment to the posthepatic septum in crocodilians
Most turtles also use diaphragmatic muscles to alter volume of cavity within the shell.

10. Avian Lungs Birds- modified lungs and ducts
Air sacs associated with lungs
Increase respiratory capacity for flight
Figure 12.9: Lower respiratory
tract of bird.

11. Trachea Passageway to lungs Larynx- voice box at head
Laryngeal cartilages
Sound produced- vocal sac
Snake hissing- expulsion of air from lungs
Figure 12.10: Human trachea and larynx (see book figure 13.13b).

12. Trachea Birds- Syrinx instead of larynx Mammals- man has larynx
Lower end of trachea
Not homologous to larynx
Incapable of producing sound
Mammals- man has larynx
Different cartilages
Epiglottis over glottis to larynx
Diaphragm
Figure 12.11: Asymmetrical bronchotracheal syrinx of duck (book figure 13.16).

13. Accessory Respiratory Organs
Yolk sac
In embryo
Skin
Many fish and amphibians
Ex: African Clawed frog (Xenopus)- chin barbels
Rectum & Cloaca
Highly vascularized in some fish
Ex: Aquatic turtles

14. Literature Cited
Figure 12.1 & 12.4: Kardong, K. Vertebrates: Comparative Anatomy, Function, Evolution. McGraw Hill, 2002.
Figure 12.2, 12.3, 12.7, 12.9 & 12.11: Kent, George C. and Robert K. Carr. Comparative Anatomy of the Vertebrates. 9th ed. McGraw-Hill, 2001.
Figure 12.5:
Figure 12.6:
Figure 12.8:
Figure 12.10: