Understanding Epithelial and Connective Tissues in Human Body

1. Tissues Chapter 4

2. Tissues • groups of cells with common role • 4 basic types: • Epithelial • Connective • Muscular • Nervous

3. Epithelial Tissue • Cells close together – continuous sheets • Cover surfaces & line cavities- always a free surface =Apical surface • Basement membrane of connective tissue • No blood vessels- avascular • Have a nerve supply • High capacity for cell division.

4. Categories- Table 4.1 • Simple epithelium = • 1 layer of cells • Stratified Epithelium= • more than 1 layer of cells • Cell Shapes = • squamous, cuboidal, columnar, transitional (change shape)

5. Simple Epithelium • Squamous= single layer of flat cells. • Important for filtration (kidneys) or diffusion (lungs & capillaries) • Called endothelium when lining heart, blood and lymphatic vessels • Called mesothelium when in serous membranes

6. Simple Squamous Epitheliumsingle layer of flat cells

7. Simple Squamous Epitheliumsingle layer of flat cells

8. Simple Squamous Epitheliumsingle layer of flat cells

9. Simple Cuboidal Epitheliumcube shaped cells, rounded nuclei

10. Simple Cuboidal Epitheliumcube shaped cells, rounded nuclei

11. Simple Columnar EpitheliumMay be ciliated or non-ciliated

12. Simple Columnar EpitheliumMay be ciliated or non-ciliated

13. Simple Columnar EpitheliumMay be ciliated or non-ciliated

14. Simple Columnar EpitheliumMay be ciliated or non-ciliated

15. Pseudostratified Columnar appears stratified: nuclei at various levels

16. Pseudostratified Columnar appears stratified: nuclei at various levels

17. Stratified Squamous Epithelium • Apical layer cells are flat • Deep layers vary from cuboidal to columnar • Cells in the basal layer divide and move upward toward apical surface • Found in areas of surface wear & tear

18. Table 4.1f figure 1

19. Table 4.1f figure 2

20. Stratified Cuboidal Epitheliumrare

21. Stratified Cuboidal Epitheliumrare

22. Stratified Columnar Epitheliumrare

23. Stratified Columnar Epitheliumrare

24. Transitional Epitheliumvariable in appearance—cells can stretch

25. Transitional Epitheliumvariable in appearance—cells can stretch

26. Glandular Epithelium-Endocrine

27. Glandular Epithelium-Endocrine

28. Glandular Epithelium-Endocrine

29. Glandular Epithelium-Endocrine

30. Connective Tissue • Most abundant tissue type • small cells far apart • large amount of extracellular material (matrix) • Often good blood supply • Found between other tissues • Classified using matrix characteristics

31. Connective Tissue Cellsvary with tissue type • Fibroblasts- present in several tissues • secrete fibers & ground substance • Macrophages- from monocytes • Engulf bacteria & cell debris by phagocytosis • Plasma cells- develop from B lymphocytes • Make antibodies

32. Connective Tissue Cells • Mast cells- near blood cells • part of reaction to injury- histamine • Adipocytes= fat cells or adipose cells • Store triglycerides (fat)

33. Extracellular Matrix • Fluid, gel or solid plus protein fibers • Ground substance-between cells and fibers • Fibers- 3 types • Collagen fibers: very strong & flexible • Elastic fibers: smaller stretch and return to original length • Reticular fibers: provide support & strength • found in basement membranes & organ support

34. Figure 4.2

35. Loose Connective Tissue • Areolar • Adipose • Reticular

36. Table 4.2a figure 1

37. Table 4.2a figure 2

38. Table 4.2b figure 1

39. Table 4.2b figure 2

40. Table 4.2c figure 1

41. Table 4.2c figure 2

42. Classification • Dense Connective tissue • Dense regular • Dense irregular • Elastic

43. Table 4.2d figure 1

44. Table 4.2d figure 2

45. Table 4.2e figure 1

46. Table 4.2e figure 2

47. Table 4.2f figure 1

48. Table 4.2f figure 2

49. Cartilage • Dense network of collagen & elastic fibers embedded in chondroitin sulfate • stronger than dense fibrous • Cells = chondrocytes • Occur singly or in groups • Found in spaces called lacunae • Surrounded by perichondrium • No blood vessels or nerves

50. Classification - Cartilage • 3 types • Hyaline- fibers not easily visible • Fibrocartilage- fibers visible • Strongest type. E.g. in vertebral discs • Elastic- chondrocytes in threadlike network e.g. ear cartilage