1. Friday October 16, 2015
AIM: How is Connective tissue categorized? Do Now: Homework: Read chapter 4, Really… Read it! Work on Homework packet I a gave out yesterday.

2. Anatomy and Physiology Chapter 4 Tissue: The Living Fabric
2: Connective Tissue

3. Connective tissue proper Cartilage Bone Blood
Found throughout the body
Most abundant and widely distributed in primary tissues
Connective tissue proper
Cartilage
Bone
Blood

4. Connective Tissue
Figure 4.6

5. Functions of Connective Tissue
Binding and support
Protection
Insulation
Transportation
Examples – bone & cartilage support and protect body organs (skeleton); fat protects organs and provides reserve energy fuel

6. Characteristics of Connective Tissue
Connective tissues have:
Mesenchyme (embryonic tissue) as their common tissue of origin
Potential to develop into bone, cartilage, blood
Varying degrees of vascularity (avascular, poorly vascularized, rich supply of blood)
Nonliving extracellular matrix, consisting of ground substance and fibersweight bearing, tension)
Most have nerve supply

7. Connective Tissue: Embryonic
Mesenchyme – embryonic connective tissue
Gel-like ground substance with fibers and star-shaped mesenchymal cells
Gives rise to all other connective tissues
Found in the embryo

8. Structural Elements of Connective Tissue
Ground substance – unstructured material that fills the space between cells
Fibers – collagen, elastic, or reticular
Cells – fibroblasts, chondroblasts, osteoblasts, and hematopoietic stem cells

9. Interstitial (tissue) fluid (extracellular matrix)
1. Ground Substance
Interstitial (tissue) fluid (extracellular matrix)
Adhesion proteins – fibronectin and laminin
CT ‘glue’ – cells attach themselves to matrix
Proteoglycans – glycosaminoglycans (GAGs)
Trap water, forms fluid or gel
Functions as a molecular sieve through which nutrients diffuse between blood capillaries and cells
Dissolved substances must pass through from capillaries to cells

10. Ground Substance: Proteoglycan Structure
Figure 4.7

11. 2. Fibers Collagen – tough; provides high tensile strength
Made of fibrils – stronger than steel
White fibers
Elastic – long, thin fibers that allow for stretch
Elastin, allow recoil
Skin, lungs, blood vessel walls
Yellow fibers
Reticular – branched collagenous fibers that form delicate networks

12. 2. Fibers
Reticular – branched collagenous fibers that form delicate networks
Short and very thin or fine collagenous fibers (continuous with collagen fibers)
Branch extensively, forming tight network called reticulum.
Surround small blood vessels and support soft tissue of organs
Form internal framework of glands
Join connective tissues to other types of tissues (basement membrane of epithelial tissues and around capillaries.
Reticular fibers are inelastic and made of collagen called reticulin.

13. 3. Cells
Undifferentiated, actively mitotic – secrete ground substance and fibers (blasts = forming)
Fibroblasts – connective tissue proper
Chondroblasts – cartilage
Osteoblasts – bone
Hematopoietic stem cells – blood
Others: White blood cells, plasma cells, macrophages, and mast cells, fat cells

14. Areolar Connective Tissue: Model
Figure 4.8

15. AIM: How is connective tissue categorized
AIM: How is connective tissue categorized? Do Now: Homework: Read chapter 4. Should be half way done at least. Work on Homework packet – due Tomorrow.

16. Two subclasses of Connective Tissue Proper
Loose Connective Tissue -
Areolar
Adipose
Reticular
Dense Connective Tissue
Dense Regular
Dense Irregular
Elastic

17. Connective Tissue Proper: Loose
Areolar connective tissue
Gel-like matrix with all three connective tissue fibers (collagen, elastic, reticular)
Cells - Fibroblasts, macrophages, mast cells, and some white blood cells
Widely distributed throughout the body

18. Locations & Structural features of Areolar CT – type of loose CT
Epithelia of body (forms lamina propria of mucous membranes; packages organs, surrounds capillaries.
Structural feature:
loose arrangement of fibers.
Rest of matrix occupied by ground substance (appears as empty space under microscope)
Edema – when body region is inflamed, areolar soaks up excess fluid like sponge, becomes puffy

19. Connective Tissue Proper: Loose
Figure 4.9a

20. Connective Tissue Proper: Loose
Adipose connective tissue
Matrix similar to areolar connective tissue with closely packed adipocytes (fat cells)
Chicken wire appearance
Reserve food (fuel) stores, insulates against heat loss, and supports and protects
Found under skin, around kidneys, within abdomen, and in breasts
Local fat deposits serve nutrient needs of highly active organs

21. Connective Tissue Proper: Loose
Figure 4.9b

22. Connective Tissue Proper: Loose
Reticular connective tissue
Loose ground substance with reticular fibers
Reticular cells lie in a fiber network
Forms a soft internal skeleton, or stroma, that supports other cell types (WBC, mast, macrophages)
Found in lymph nodes, bone marrow, and the spleen

23. Connective Tissue Proper: Loose
Figure 4.9c

24. Connective Tissue Proper: Dense Regular
Parallel collagen fibers with a few elastic fibers
Parallel to direction of pull (tendons, ligaments)
Major cell type is fibroblasts b/n fiber bundles
Attaches muscles to bone or to other muscles, and bone to bone
Found in tendons, ligaments, and aponeuroses, fascia

25. Connective Tissue Proper: Dense Regular
Figure 4.9d

26. Connective Tissue Proper: Dense Irregular
Irregularly arranged thick collagen fibers with some elastic fibers
Major cell type is fibroblasts
Withstands tension in many directions providing structural strength
Found in the dermis, submucosa of the digestive tract, and fibrous organ capsules

27. Connective Tissue Proper: Dense Irregular
Figure 4.9e

28. Connective Tissue: Hyaline Cartilage
Most abundant type
Amorphous, firm matrix with imperceptible network of collagen fibers
Chondrocytes lie in lacunae (cavities)
Function: Supports, reinforces, cushions, and resists compression
LOC: Forms the costal cartilage
Found in embryonic skeleton, the end of long bones, nose, trachea, and larynx

29. Connective Tissue: Hyaline Cartilage
Figure 4.9f

30. Connective Tissue: Elastic Cartilage
Similar to hyaline cartilage but with more elastic fibers
Maintains shape and structure while allowing flexibility
Supports external ear (pinna) and the epiglottis

31. Connective Tissue: Elastic Cartilage
Figure 4.9g

32. Connective Tissue: Fibrocartilage
Matrix similar to hyaline cartilage but less firm with thick collagen fibers
Provides tensile strength and absorbs compression shock
Found in intervertebral discs, the pubic symphysis, and in discs of the knee joint

33. Connective Tissue: Fibrocartilage Cartilage
Figure 4.9h

34. Connective Tissue: Bone (Osseous Tissue)
Hard, calcified matrix with collagen fibers found in bone
Osteocytes are found in lacunae and are well vascularized
Fxn: Supports, protects, and provides levers for muscular action
Stores calcium, minerals, and fat
Marrow inside bones is the site of hematopoiesis

35. Connective Tissue: Bone (Osseous Tissue)
Figure 4.9i

36. Connective Tissue: Blood
Red and white cells in a fluid matrix (plasma)
Contained within blood vessels
Functions in the transport of respiratory gases, nutrients, and wastes

37. Connective Tissue: Blood
Figure 4.9j