The multicellular organism

1. The multicellular organism Dr. Ajith Sominanda(MBBS, MPhil, PhD) Department of Anatomy Faculty of Medicine-Peradeniya

2. Objectives for SBM-1/2 b. The multicellular organism 1. understand the levels of organization of the multicellular organism from cells, tissues, organs and systems and their integration in to human being 2. understand the terms “totipotent” and “pluripotent” 3. understand that the functional unit of the multicellular organism is the tissue 4. state the basic systems of the body and their functions

3. Where to find the objectives http://www.med.pdn.ac.lk http://www.pdn.ac.lk http://www.pdn.ac.lk/uop/main/faculty_centers.html http://www.med.pdn.ac.lk/curriculum/coursemap.html http://www.med.pdn.ac.lk/groups/1/y1s1/foundation.html http://www.med.pdn.ac.lk/groups/1/y1s1/foundation.html

4. Living versus Non-living things@ First School Years Living Things Non-Living Things

5. Living versus Non-living things

6. An attempt to describe a living thing A something capable of • Growing • Using energy for its activities • Formation of its copies / offspring appears to be a living thing Scientific term for living thing is ORGANISM

7. Copies

8. Living versus Non-living things

9. Life at molecular level Inorganic molecules organic moleculesbiomolecules

10. Are Prion protein and virus organisms ? Prion = ‘Protein’ + ‘infectious’ Infectious proteins

11. The scientific definition An organized thing or a system capable of self Growth Synthesis and degradation of materials by utilizing or releasing energy-Metabolism Keep a balance of the activities and conditions - Homeostasis Response to the environmental stimuli Reproduction

12. What is a cell • The cell is considered as the basic structural unitof the living things (organism)

13. Unicellular Versus Multicellular organisms • Organisms • Multicellular organism • Unicellular organism

14. Process of Unicellular to multi cellular organization The long process -The evolution • The short process – • The Embryogenesis, growth & Development

16. Ability (Potential) of a cell to change (differentiate) into different cell types during embryogenesis Totipotent - cells having total (full) potential to differentiate into another cell Pluripotent- cells having some potential to develop into another cells Unipotent cells - cells having no potential to develop into another cell Germinal cell layers

17. Organization of cells to form specific functions group of cells that is aggregated to perform a specific function/s are called TISSUES Tissue is the functional unit of multi cellular organism

18. Four basic types of tissues • Epithelial Tissue • Connective tissue • Muscle Tissue • Nerve or Nervous tissue

19. Epithelial tissues

20. Connective tissue

21. Muscle tissue

22. Nervous tissue

23. Functions of tissues

24. Levels of organization of multicellular organism Level 1 Cell Level 2 Tissue Level 3 Organ Level 4 System Level 5 Organism; the human

25. Organs of the human body

26. Tissues form the organs

27. Tissues form the organs

28. What are the tissues that compose this organ A B C D

29. Tissues and organs form the systems

30. List the functions of the systems in our body • Circulatory system • Respiratory system • Alimentatory (Digestive) system • Nervous system • Endocrine system • Excretory system • Reproductive system • Lymphatic system

31. Summary

32. New Terms • Cell • Embryo • Totipotent ,pluripotent • Tissue • Organ • System • Epithelium, Epithelia • Muscle • Nerve • Glia • Bone • Cartilage • Fibroblast • Chondroblast • Osteoblast • Osteoclast • Evolution • Circulation • Respiration • Digestion • Excretion • Reproduction • Lymph, Lymphatic • Haematopoietic tissue

33. References • Molecular Cell Biology by Harvey Lodish • Basic Histology by Carlos Junqueira • WWW.

34. Thank you