Lecture #8 – Introduction to Animal Structure and Function

1. Lecture #8 – Introduction to Animal Structure and Function Images – the two most beautiful cats in the world, currently, as kittens and grownups

2. Key Concepts • What separates animals from other organisms? • Introduction to structure and function relationships – the implications of being multicellular • Hierarchical organization in animals • Tissues • Organ systems • Bioenergetics and metabolic rates

3. What do all organisms have to do to make a living??? ???

4. What do organisms have to do to make a living???

5. What makes an animal an animal? ???

6. What makes an animal an animal?

7. Structure and Function of Animal Systems • Focus on human biology, but will use comparative approach • Comparisons between animals of differing levels of complexity • We will correlate structure with function, at all levels of organization • Important theme in biology • Start with intro to basic principles • Then discussions of various organ systems

8. Critical Thinking • Life has been on this planet for 3½ billion years! • Until about 700 million years ago, all organisms were______________? Table - the geological time scale

9. It’s always fun to study the geological time scale – it reveals the history of life on earth What happened here???

10. Critical Thinking • Life has been on this planet for 3½ billion years! • Until about 700 million years ago, all organisms were

11. Multi-cellularity imposes limitations, too • In most multi-cellular organisms, not every cell is in contact with the external environment • Multi-cellular organisms develop complex morphologies that reflect their environment • Multi-cellular organisms develop complex mechanisms for resource/waste exchange with their environment • We saw these phenomena with plants – animals do the same thing

12. Critical Thinking • Terrestrial plants use a tight epidermis and a waxy cuticle to retain water • What is the analogous structure in terrestrial animals???

13. Critical Thinking • Terrestrial plants use a tight epidermis and a waxy cuticle to retain water • What is the analogous structure in terrestrial animals???

14. Critical Thinking • Most animals (even many aquatic animals) urinate. Why??? • Do plants pee???

15. Critical Thinking • Most animals (even many aquatic animals) urinate. Why??? • Do plants pee???

16. Critical Thinking • Most animals (even many aquatic animals) urinate. Why??? • Do plants pee???

17. Constraints On Size And Shape:The physical environment affects animal evolution – as it does with all organisms • Simple physics • Flight, soil burrowing, swimming for speed… • The physical environment • Dense water or soil, thin air • Often leads to convergent evolution of shape Images - convergent evolution of spindle-shaped swimmers

18. Constraints On Size And Shape:The necessity of exchange with the environment affects animal evolution…. • Resource/waste exchange with the environment • Diffusion at the surface was characteristic of the earliest animals • Limits size • Limits shape to thin, flat, open • Limits complexity • Mostly quite simple animals Diagram - 2 tissue layers in Cnidarians

19. Most animals have much more complex exchange systems • Exchange occurs at internal epithelia • Huge surface area is characteristic • Fun factoids from humans: • Lungs have 100 m2 of surface area (about ½ as big as room) • Small intestine has surface area of a tennis court • 80 km of tubules in a single kidney • 100,000 km of blood vessels = almost 3x circumference of the earth

20. Critical Thinking • How on earth do such large surface areas fit into our bodies???

21. Critical Thinking • How on earth do such large surface areas fit into our bodies??? Micrographs - lung and intestinal tissues Small Intestine Tissue

22. Exchange with environment is not direct for most animals • Body is covered with waterproof surface • Complex organ systems exchange materials • Organ systems are linked together, but not usually directly • Most organ systems are separated by interstitial fluid = a water-based solution that surrounds all cells in the animal body • Transport occurs through the interstitial fluid

23. Indirect exchange between organism and environment, and between organ systems Diagram - organization of organ systems showing indirect exchange through the interstitial fluid; same diagram on #29

24. Critical Thinking • Do nutrients leap from our breakfast cereal to our cells??? • Why do animals need nutrients anyways???

25. Critical Thinking • Do nutrients leap from our breakfast cereal to our cells??? • Why do animals need nutrients anyways???

26. Critical Thinking • Do nutrients leap from our breakfast cereal to our cells??? • Why do animals need nutrients anyways???

27. Exchange with environment is not direct for complex animals • Body is covered with waterproof surface • Complex organ systems exchange materials • Organ systems are linked together, but not usually directly • Organ systems are separated by interstitial fluid = a water-based solution that surrounds all cells in the animal body • Transport occurs through the interstitial fluid

28. Indirect exchange between organ systems occurs via the interstitial fluid one big exception: the Malphigian excretory tubules in insects are directly connected to the digestive tract

29. All complex organisms have a hierarchical organization Diagram - cells - organism in a zebra • Cells • Tissues • Organs • Organ systems • Organism Form Reflects Function!!!

30. Critical Thinking • Think of your heart, or this zebra’s – how are structure and function related???

31. Critical Thinking • Think of your heart, or this zebra’s – how are structure and function related???

32. Form and function are correlated from cells  whole organism • We learned about cells in 111…. • Cells • Tissues • Organs • Organ systems • Organism

33. Four major tissue types –read more in text Diagram – tissue types

34. Epithelial Tissues • Sheets of cells that cover the body surfaces and line many of the internal organs • Base of epithelial tissue is attached to a basement membrane • The free (exposed) surface has cells that are either cuboidal, columnar or squamous (tile shaped) • Shape reflects function! • Some epithelia waterproof, some leak, some secrete, some slough off….

35. Epithelial tissues Diagram – sub-types of epithelial tissues Which do you think are waterproof??? Which leaky??? Which secrete??? Which slough off???

36. Connective Tissues • Cells held in a fibrous or fluid extra-cellular matrix • Matrix generally secreted by the cells • Many types and sub-types of connective tissue • Loose – bind and shape • Adipose – store fat • Fibrous – strong connections • Cartilage – cushions • Bone – support system • Blood – connects tissues to resources

37. Critical Thinking • What makes the “bones” of plants???

38. Critical Thinking • What makes the “bones” of plants???

39. Critical Thinking • How about the blood???

40. Critical Thinking • What makes the “blood” of plants???

41. Muscle Tissue • Composed of cells that can contract • Skeletal = enable movement, attached to bones by tendons • Voluntary = under conscious nervous system control • Cardiac = forms the heart • Involuntary • Smooth or visceral = surround the digestive tract, other organs • Involuntary

42. Nervous Tissue • Transmits messages from one part of body to another • Nerve cells have a central cell body + appendages that carry messages toward or away from the cell (dendrites/axons) • Appendages may be a meter long in humans!

43. Critical Thinking • Do all animal tissue types have directly analogous tissue types in plants??? • Epithelial??? • Connective??? • Muscle??? • Nervous???

44. Critical Thinking • Do all animal tissue types have directly analogous tissue types in plants??? • Epithelial – • Connective – • Muscle – • Nervous –

45. Organs • Composed of two or more types of tissues organized into a functional unit • Tissues are often in layers, or they may be integrated throughout the organ • Stomach has layers of epithelial, connective, muscle, connective • Skin has layers of epithelial, connective, muscle • All tissues have blood vessels and nerve tissues integrated

46. Most animals have body cavities • These are fluid filled spaces that cushion and suspend organs • Sometimes they also give the body shape • In vertebrates, many organs are held in place in the body cavity by layers of connective tissues (mesenteries) and sheets of muscle (diaphragm) Diagram – body cavities

47. Organ Systems: groups of related organs that maintain various body functions • Complex organ systems are present in all higher animals • All organ systems are interdependent • Functions are coordinated (ex: digestive + vascular) • All systems work together to maintain homeostasis (~constant internal conditions, more on this later)

48. Organ Systems:most complex animals have 11 major organ systems – image search for a table like this one Table – all the organ systems found in a complex animal

49. Diagrams – closeups of the major organ systems; similar diagrams on next 4 slides Digestive Circulatory

50. Respiratory Immune