Epithelial and Connective Tissues: Key Characteristics and Functions

1. 9/30 and 10/1 • Practice quiz – ID epithelial tissues • Notes – connective tissues • Continue histology virtual lab

9. Connective Tissue • Binds, supports, protects, insulates, and transports

10. Characteristics 1. Varying degrees of vascularity (fat vs. cartilage) 2. Non-living component (matrix) and cells (secrete the matrix)

11. Matrix • Ground substance – fluid, proteins • Fibers • Collagen – tough and strong • Elastic - stretchy • Reticular – network of thin fibers

12. Matrix-making Cells • Fibroblasts • Chondroblasts • Osteoblasts • Hemocytoblasts • “blast” = builder cell

13. Other cell types… • “Clast” cells are “destroying” cells. • “Cytes” are mature cells

14. Let’s Get Organized… • Fibrous CT – loose, dense, reticular, adipose • Cartilage – hyaline, fibro, elastic • Bone • Blood

15. Loose (Areolar) CT • Most abundant CT • Under skin • Around organs • Surrounds capillaries • Gel-like matrix, collagen and elastin fibers • Lots of fibroblasts, macrophages

16. Loose (Areolar) CT Continued • Several Functions • Protection/cushion/support • Binding • Retains body fluids • Fights infection

17. Dense CT • 2 kinds – regular and irregular • Lots of fibers, few cells • Regular – fibers parallel • Tendons, ligaments • Irregular – fibers not parallel • Mat of strong tissue • Dermis

18. Dense Irregular CT

19. Reticular CT • 3-D network of fibers • Framework of spleen, lymph nodes, bone marrow • Phagocytes • Defense, filtering

20. Adipose Tissue • Like LACT, more fat cells fewer other cells • Storage for excess food • Insulation • Protection, cushioning

21. Cartilage • Tough but flexible • Avascular • Looses mitotic ability w/age • Matrix – tough, gristle like • Chondrocytes in lacunae

22. Hyaline (“glassy”) Cartilage • Supports and cushions • Few fibers • Most abundant • Ends of bones, rings of respiratory tubes

23. Fibrocartilage • Similar to hyaline but more fibrous • Absorbs shock • Strongest and most durable • Between vertebrae, meniscus of knee

24. Elastic Cartilage • More elastic fibers • Flexibility/structure • Ear, larynx

42. Blood • No ground substance or fibers • Plasma and blood cells • Erythrocytes • Leukocytes • Thrombocytes • Transportation

43. Bone Tissue • Supports, protects, stores, produces • Osteocytes in lacunae • Matrix has fibers and mineral salts

44. What is Nervous Tissue? • Communication and regulation • Neurons and neuroglia (supporting cells)

45. 3 Types of Muscle Tissue • Skeletal – attached to bones • Smooth – walls of organs, blood vessels, etc. • Cardiac - heart

46. Skeletal Muscle • Voluntary • Striated • Multinucleate • Long, narrow cells

47. Cardiac Muscle • Only in the heart • Involuntary • Striated • Long, branching cells • Intercalated discs • Multinucleate

48. Smooth Muscle • Function – propulsion • No striations • 1 nuclei • Tightly packed into a sheet • Involuntary

49. Practice Quiz