1. COMPARING VERTEBRATE BODY SYSTEMS
Skeletal Systems
Digestive Systems
Circulatory Systems
Respiratory Systems
Nervous Systems

2. COMPARING BODY SYSTEMS
The job any machine can do depends upon its parts and their arrangement.
A saw is able to cut wood because it has teeth.
A sewing machine can pierce cloth because it has a needle.
Every kind of animal and every kind of plant also has its own peculiar structure. How and where it can live depends upon its structure.

3. In comparative anatomy the structures of various animals are studied and compared.
The drawings (next slide) show the digestive systems of the earthworm, the fish, and the frog. The colored lines trace the animals' digestive tracts.
As can be seen, the systems are alike in many ways. Each animal has a mouth, a pharynx, an esophagus, an intestine, and an anus.
There are also differences. For example, the frog and the fish have livers whereas the earthworm has a gizzard.
The differences enable each animal to digest the food found where it lives.

4. The drawings show other organs that equip each animal for its way of life. The fish, which lives in water, has gills through which it breathes. It has no lungs. The frog, which lives on land as well as in water, is equipped with lungs for air breathing. The earthworm has neither lungs nor gills. It breathes through its skin.

5. YOUR TASK: Understand the basic function of each body system.
Sketch the system in each vertebrate class if possible.
Find the common elements of the system that are in all classes.
Find the elements that are unique to a particular class.
How do the body features help this creature survive in his ecological niche?

6. Skeletal Systems
Vertebrates have a more or less rigid group of structures composed of cartilage or bone or of a combination of these two connective tissues.
In vertebrates, the skeleton formed in the embryo is initially cartilaginous; bone and calcium are deposited as the organism matures. In humans, the process of bone hardening, or ossification, is completed at about the age of 25. The last bone to ossify is the breastbone.
The total number of bones in any animal varies with its age; many bones fuse together during the ossification process. The average number of bones in a young human is 200, exclusive of the 6 ossicles found in the ears.

7. SKELETAL SYSTEMS: FISH
Why does a fish have more vertebrae than other vertebrate animals?
Why is the skull shaped this way?

8. SKELETAL SYSTEM:FROG Why does a frog have no ribs?
Why are the toes and fingers (phalanges) so long?
Why is the trunk so short and the legs so long?

9. SKELETAL SYSTEMS: TURTLE
What is different about a turtle’s vertebrae?
Why is it like that?
Why are the legs so short?
Why are there fewer vertebrae in his neck than in a bird or human?

10. SKELETAL SYSTEMS: BIRD
Why are a bird’s bones hollow?
What is the function of the “keel”? (Think about white meat on a turkey or chicken!)
Why are there so many vertebrae in a bird’s neck?
What ability does that give a bird?
Why is that vital?

11. SKELETAL SYSTEMS: HUMAN
Humans have an opposable thumb. Why does that matter?
Why is there a curve to a human spine?
What does the pelvis do in a human?

12. VERTEBRATE DIGESTIVE SYSTEMS
What happens to food after it is eaten? The all creatures use various kinds of food for energy and growth.
To be used, however, food must be changed into a form that can be carried through the bloodstream.
The body's process of extracting useful nutrients from food is called digestion.

13. VERTEBRATE DIGESTIVE SYSTEMS: FISH
What is the function of the liver, stomach and intestine?

14. VERTEBRATE DIGESTIVE SYSTEMS: FROG
Why does a frog have a
urinary bladder but a fish
doesn’t?
What is the difference
between the large intestine
and the small intestine?
Why would a frog have both large
and small intestines but not a frog?

15. VERTEBRATE DIGESTIVE SYSTEM: TURTLE

16. VERTEBRATE DIGESTIVE SYSTEMS: BIRD
Why is it helpful to a bird to not have a heavy jaw and teeth?
Why does a bird have a gizzard?
What does the crop do?

17. VERTEBRATE DIGESTIVE SYSTEMS: HUMAN

18. VERTEBRATE CIRCULATORY SYSTEMS

19. VERTEBRATE CIRCULATORY SYSTEMS: FISH

20. VERTEBRATE CIRCULATORY SYSTEMS: FROG

21. VERTEBRATE CIRCULATORY SYSTEMS: TURTLE

22. VERTEBRATE CIRCULATORY SYSTEMS: BIRD

23. VERTEBRATE CIRCULATORY SYSTEMS: HUMAN

24. VERTEBRATE RESPIRATORY SYSTEMS

25. VERTEBRATE RESPIRATORY SYSTEMS: FISH

26. VERTEBRATE RESPIRATORY SYSTEMS : FROG

27. VERTEBRATE RESPIRATORY SYSTEMS: TURTLE

28. VERTEBRATE RESPIRATORY SYSTEMS: BIRD

29. VERTEBRATE RESPIRATORY SYSTEMS: HUMAN

30. VERTEBRATE NERVOUS SYSTEMS

31. VERTEBRATE NERVOUS SYSTEMS:FISH

32. VERTEBRATE NERVOUS SYSTEMS:FROG

33. VERTEBRATE NERVOUS SYSTEMS:TURTLE

34. VERTEBRATE NERVOUS SYSTEMS:BIRD

35. VERTEBRATE NERVOUS SYSTEMS:HUMAN