Define comparative anatomy. Classifiy the phylum chordata. Discuss the limb development of tetrapods. Describe the features of tetrapods. Explain the structure and function of the limb of tetrapods. Discuss homology and analogy in relation to the limb of tetrapods. Presented by Dr. Farhana Taher Sumya Guided by Dr. Zinnat Ara Yesmin

1. Comparative Anatomy
of the Limb
Presented by Dr. Farhana Taher Sumya
Guided by Dr. Zinnat Ara Yesmin

2. Objectives
 Define comparative anatomy
 Classifiy the phylum chordata
 Discuss the limb development of tetrapods
 Describe the features of tetrapods

3. Objectives (contd...)
 Explain the structure and function of the limb of
tetrapods
 Discuss homology and analogy in relation to the
limb of tetrapods

4. Comparative Anatomy

5. Kingdom: Animalia
Phylum:chordata
Group:
Craniata
Subphylum:
Gnasthostomata
Superclass:
Tetrapoda
Class:
Mammalia
Class:
Aves
Class:
Reptilia
Class:
Amphibia
Superclass: Pisces
Subphylum:
Agnatha
Group:
Acrania
Classification of phylum chordata

6. Features of Tetrapods
 Paired appendages are limb which are
pentadactyl
 Sternum present
 Lung present
 Number of skull bone is reduced

7. Features of Tetrapods (contd…)
Amphibia (e.g: Frog, toad)
 Pentadactyl limbs and no nails on claws
 3 chambered heart and lung present
Reptilia (e.g: turtle, lizard, snake)
 Pentadactyl limbs with claws except snake and
lizards
 3 chambered heart and lung present

8. Aves(Bird)
 Limbs with claws
 Lung present and no urinary bladder
Mammalia (e.g: cat,dog,monkey,human)
 Pentadactyl limbs with claws,nails ,hoof at the end of
digit
 4 chambered heart and lung present
Features of Tetrapods(contd)

9. Limb development of tetrapods
 Limb bud
 Apical ectodermal ridge
 Apoptosis

10. Limb bud

11. Apical ectodermal ridge

12. Apoptosis

13. Structure and function of the
forelimb of tetrapods
Amphibia Reptilia

14. Structure and function of the forelimb of tetrapods (contd….)
Aves Mammalia

15. Structure and function of forelimb of tetrapods (contd….)

16. Comparison of primates hand

17. Structure and function of the
hindlimb of tetrapods
Amphibia Reptilia

18. Structure and function of the hindlimb of tetrapods (Contd.)
Aves Mammalia

19. Structure and function of the hindlimb of tetrapods (Contd.)

20. Homology

21. Homology (contd.)

22. Analogy

23. Analogy (contd.)

24. Homology Analogy
Similar in anatomy dissimilar in
anatomy
Doing dissimilar
function
Doing similar
function

25. Homology & Analogy

27. Homology (contd)
 We have probably noticed that our arms are shorter than our legs.
However, this is not the case in all species. Many species of monkeys, in
particular, have longer arms than legs, or some, like dogs and cats, have
four limbs all of similar length. This is because the specific function of
those limbs differs from humans. Monkeys do a lot more climbing than
walking, while dogs and cats use all four limbs to walk and run.
 However, despite small differences in function, they still have one
upper arm bone, followed by two lower arm bones, wrist bones and
finger bones - just like humans. Although, sometimes the length or
number of the bones and the shape of the muscles used to move their
arms and legs may vary slightly. But, despite slight variations, the order
in which they are put together and the general function of motion are
similar to those in humans and other mammals.

28. Homology
The structure which are similar in their morphology, anatomy,
genetics and embryology but dissimilar in their function is called
homologous structure. The relationship between the
homologous structure is called homology.