1. Lab Exercise #8
Connective Tissue

2. Characteristics of Connective Tissues
Specialized cells
Solid extracellular protein fibers
Fluid extracellular ground substance
These latter two extracellular features are called Matrix

3. The Matrix
The extracellular components of connective tissues (fibers and ground substance):
majority of volume
determines specialized function
e.g. connective tissue proper  syrupy liquid
cartilage  gel-like matrix
blood  fluid matrix
bone  crystalline solid

4. Classification of connective tissues

5. Lab #8. Connective Tissue
Today’s Lab
Lab #8. Connective Tissue

6. Connective Tissue Connective tissue proper Fluid connective tissue
Supportive connecting tissue

7. Connective tissues Bone Connective tissue proper
Loose connective tissue
Areolar
Adipose
Reticular
Dense connective tissue
Dense regular
Dense irregular
Elastic tissue
Fluid CT
Blood
Supporting CTs
Cartilage
Hyaline cartilage
Elastic cartilage
Fibrocartilage
Bone

8. Areolar tissue
A loose CTP

9. Areolar

10. Areolar: what to look for
Fibroblasts
Collagen fibers
Elastic fibers
Mast cells and macrophages
Found? Throughout body, under dermis, divides skin from underlying tissues

11. Fibroblasts
Resting fibroblasts typically have so little cytoplasm that the cells appear, by light microscopy, as "naked" nuclei

12. Fibroblast

13. Adipose tissue
Another lose CTP (note nucleus)

14. Adipose: what to look for
Lots of cytoplasm
Slim nuclei pushed off the side
Found? You know where

15. Reticular tissue
The third type of loose CTP

16. Reticular tissue

17. Reticular: what to look for
Reticular fibers (network)
Found? Internal framework in many sort organs (liver, spleen) supporting the parenchyma

18. Dense CTP Dense regular – strength in one direction
Dense irregular – strength in all directions
Elastic tissue - pliable

19. Dense regular

20. Dense regular: what to look for
Thick parallel bundles of collagen
Small fibroblasts in between bundles
Found? Tendons, ligaments, deep fascia.

21. Dense irregular

22. More dense irregular

23. Dense irregular: what to look for
Mesh of collagen fibers (irregular looking)
Interspersed fibroblasts
Found? Dermis of skin, periosteum, perichondrium

24. Elastic tissue

25. Elastic tissue: what to look for
Elastic fibers (instead of collagen fibers) in large bundles
Fibroblasts
Found? Between vertebrae, in blood vessel walls (underneath endothelium)

26. Fluid CT
Blood

27. Blood: what to look for RBCs
White blood cells (darker): monocytes, lymphocytes, granulocytes
Platelets

28. Supportive CT Cartilage – gelatinous, padding Hyaline cartilage
Elastic cartilage
Fibrocartilage

29. Hyaline cartilage
Glasslike because fibers not visible

30. More hyaline
There are collagenous and elastic fibers lying in the cartilage matrix but they are invisible because their “refractive index” is the same as that of the matrix (like cornea)

31. More hyaline

32. Hyaline cartilage

33. Hyaline
Hyaline cartilage (lavender matrix), with perichondrium (pink) outside it. The latter is a dense regular collagenous CT. Cartilage cells = chondrocytes, and they are lying in the lacunae.

34. Hyaline cart.: what to look for
Perichondrium
Chondroblasts (make the matrix fibers and ground)
Chondrocytes and lacunae
Where? Most joints, nasal septum

35. Elastic cartilage

36. Elastic cart: what to look for
Many elastic fibers in matrix
Perichondrium
Chondroblasts
Chondrocytes in lacunae

37. Fibrocartilage

38. Fibrocartilage: what to look for
Irregular, wispy collagen fibers
Chondrocytes
Found? Intervertabral discs of spine, pads in knee joint

39. Supportive CT: Bone

40. Detail of lacuna, showing radiating canaliculi
Detail of lacuna, showing radiating canaliculi. Tissue fluid from the capillaries and connective tissue of the Haversian canal can seep through these spaces and channels, bringing nutrients to the stellate osteocytes residing there.

41. Bone: what to look for Osteon (whole circular structure)
Concentric lamellae (of matrix)
Central canal (at center of lamellae)
Osteoblasts
Osteocytes in lacunae
Canaliculi
Found? Bones!

42. Exercises Look at all slides
Draw an example of each tissue (11) on paper provided
6 CTP (3 loose, 3 dense)
1 Fluid CT (blood)
4 Supportive CT (3 cartilage, 1 bone)
Due next Tuesday (6/3)

43. Turn in next Tuesday
Drawings of 11 tissues
Lab Report 8 (A,B,E)