1. Chapter 6 Classification of Tissues

2. Tissues and tissue types • Tissues are: • Group of cells similar in structure an function • Tissues are organized into organs • Histology = study of tissues • The four tissue types are: • Epithelial • Connective • Muscular • Nervous

3. Functions of epithelium • Physical protection • Secretion • Sensory perception • Absorption • Filtration • Excretion

4. Epithelial tissue • Includes glands and epithelium • Glands are secretory • Avascular • Polarity • Regeneration • Cellularity • Supported by connective tissue • Attached to a basement membrane

5. Basement Membrane • Amorphous substance. • Divided in 2 layers: • Lamina lucida (basal) • Secreted by the epithelium • Lamina densa (reticular) • Secreted by the connective tissue

7. Specializations of epithelium • Ciliated • Microvilli • Stereocilia • Flagella

8. Classification of epithelia • Number of cell layers • Simple • Stratified • Shape of apical surface cells • Squamous • Cuboidal • Columnar

12. Cuboidal Epithelia

14. Cuboidal Epithelia Figure 4.4b

15. Transitional Epithelium Figure 4.4c

17. Columnar Epithelia Figure 4.5a

19. Columnar Epithelia Figure 4.5b

21. Columnar Epithelia Figure 4.5c

22. Glandular epithelia • Epithelium that secrete substances • Exocrine glands • Secrete through ducts onto the surface of the gland • Endocrine glands • Release hormones into surrounding fluid. Ductless glands.

24. Part 2

25. Connective Tissues

26. Connective tissue functions and classification: • Protects • Supports • Bind tissues together • Classification: • Embryonic • Mesenchime • Loose connective tissue, mucous • Adult

27. A Classification of Adult Connective Tissues

28. Connective tissues characteristics • No free surface • Vascular • Scanty in tendons • Except cartilage • Supports the body • Maintain body form

29. Components of the connective tissue 1)Extracellular matrix • Ground substance • Amorphous • Binds cells to fibers • Colorless • Homogeneous • Liquid, semisolid, gel-like, or hard

30. Matrix • Fibers • Collagen (white) • Most abundant • Brings flexibility and strength to the tissue • Thicker one • Elastic(yellow) • Brings elasticity to the tissues • Can stretch and recoil

31. Fibers • Reticular • Thinnest one • Found in smooth muscle and framework of the organs • Brings flexibility to organs that need changes in volume

34. Components of the connective tissue 2) Cells • Fibroblast • most abundant • Synthesis of fibers and ground substance • Macrophage • Phagocytic capacity

35. Components of the connective tissue • Adipocytes • Closely packed • Signet ring cell • Nucleus eccentric and flat • Mesenchymal cells • Mast cells • Releases histamin • Responsible for allergic reactions • Lymphocytes, etc

36. The Cells and Fibers of Connective Tissue Proper

37. Connective tissue proper • Classified as loose or dense • Loose • Areolar tissue • Adipose tissue • Reticular tissue • Rich blood supply

38. Connective tissue proper • Dense • Dense regular • Dense irregular • Elastic • Poor blood supply

39. Connective Tissue in Embryos

44. Dense Connective Tissues Figure 4.12a

45. Dense Connective Tissues Figure 4.12b

46. Dense Connective Tissues Figure 4.12c

50. Bone, or osseous tissue • Has osteocytes and osteoblasts • Lacuna • Little ground substance • Dense mineralized matrix • Richly Vascularized