1. They hold us all together
Connective Tissues
They hold us all together

2. Connective Tissue Hold things together Provide support and protection
Serve as frameworks
Fill spaces
Produce blood cells and prevent infection
Help repair tissue damage
Further apart than epithelial cells
Have much matrix (intercellular fluid) between them
Have good blood supply
Can be rigid or flexible
Can usually reproduce

3. TYPES OF CONNECTIVE TISSUE
1. True Connective Tissue a. Loose Connective Tissue
b. Dense Connective Tissue
2. Supportive Connective Tissue a. Cartilage
b. Bone
3. Liquid Connective Tissue
a. Blood

4. True Connective Tissue Cells
Fibroblasts: Secrete both fibers and ground substance of the matrix (wandering)
Macrophages: Phagocytes that develop from Monocytes (wandering or fixed)
Plasma Cells: Antibody secreting cells that develop from B Lymphocytes (wandering)
Mast Cells: Produce histamine that help dilate small blood vessels in reaction to injury (wandering)
Adipocytes: Fat cells that store triglycerides, support, protect and insulate (fixed)

5. Fibroblasts

6. Mast Cells

7. Macrophage

9. Connective Tissue Fibers (Matrix Fibers)
Collagen Fibers: Large fibers made of the protein collagen and are typically the most abundant fibers. Promote tissue flexibility.
Elastic Fibers: Intermediate fibers made of the protein elastin. Branching fibers that allow for stretch and recoil
Reticular Fibers: Small delicate, branched fibers that have same chemical composition of collagen. Forms structural framework for organs such as spleen and lymph nodes.

10. True or Proper Connective Tissue
Loose Connective Tissue:
a. Areolar tissue Widely distributed under epithelia
b. Adipose tissue
Hypodermis, within abdomen, breasts
c. Reticular connective tissue
Lymphoid organs such as lymph nodes

11. Loose Fibrous Connective Tissue
Forms thin, delicate membranes throughout body
Mostly fibroblasts, separated by matrix loaded with collagenous, elastic fibers
Glues skin down, fills space between muscle
It’s beneath most epithelium, highly vascularized

12. LOOSE Connective Tissue:
1. Areolar CT
consists of all 3 types of fibers, several types of cells, and semi-fluid ground substance
found in subcutaneous layer and mucous membranes, and around blood vessels, nerves and organs
function = strength, support and elasticity

13. LOOSE Connective Tissue:
2. Adipose tissue
FAT
Cells store fat droplets in their cytoplasm, enlarge
Beneath skin, in spaces between muscle, behind eyeballs, in certain abdominal membranes, on the heart, around joints
Stores energy, insulates, cushions organs, joints

14. Adipose Tissue

17. Collagenous Fibers Thick threads made from the protein collagen
Fibers in long, parallel bundles
Flexible, though not overly elastic
Have great tensile strength
Tissue containing a lot of this: dense connective tissue (or white fibers)
Present in tendons

18. ELASTIC MEMBRANES COLLAGENOUS FIBERS Aorta
                                                                                                                                             
Rat, Helly's fluid, Mallory's stain (A), Mallory-azan stain (B), 162 x.

19. Elastic Fibers Made from protein Elastin.
Fibers are branched, form complex networks
Stretchy
Called yellow fibers
In vocal cords

20. Elastic Fibers

21. Reticular Fibers Very thin collagenous fibers
Highly branched, form delicate supporting networks
Found in a variety of tissues
Ex - the liver, the kidney, the spleen, and lymph nodes

22. Reticular Fibers

23. Loose Fibrous Connective Tissue

24. True or Proper Connective Tissue
Dense Connective Tissue:
a. Dense regular connective tissue
Tendons and ligaments Function = provide strong attachment between various structures
b. Dense irregular connective tissue
Dermis of skin, submucosa of digestive tract

25. Dense Fibrous Connective Tissue
Closely packed, thick, collagenous fibers and a fine network of elastic fibers
Few cells, mostly fibroblasts
Strong, dense, good tensile strength
Common in ligaments and tendons
In the white of the eyeball, deeper skin layers
Poor vascularization; slow healing

27. Supportive Connective Tissue:
CARTILAGE:
Jelly-like matrix (chondroitin sulfate) containing collagen and elastic fibers and chondrocytes surrounded by a membrane called the perichondrium.
Unlike other CT, cartilage has NO blood vessels or nerves except in the perichondrium.
The strength of cartilage is due to collagen fibers and the resilience is due to the presence of chondroitin sulfate.

28. Cartilage Types distinguished by type of intracellular matrix
Hyaline Cartilage
Elastic Cartilage
Fibrocartilage

29. Cartilage Is partly rigid, partly flexible
It provides support, frameworks, attachments, serves as template for developing bones
Much intercellular material composed of collagenous fibers embedded in a gel-like ground substance
Chondrocytes (cartilage cells) are in small lacunae (small chambers), surrounded by matrix
Perichondrium (fibrous connective tissue) encloses cartilagenous structure. It contains blood vessels

30. Hyaline Cartilage: Most common Has fine collagenous fibers in matrix
Looks like white plastic
Found on ends of bones in joints, soft part of nose, rings in respiratory passages
Important in bone formation
Found in embryonic skeleton, at the ends of long bones, in the nose and in respiratory structures.

31. Hyaline Cartilage

32. Elastic Cartilage Has dense network of elastic fibers
More flexible than hyaline
Provides framework for ears(external) and parts of larynx
function = gives support, maintains shape, allows flexibility

33. Elastic Cartilage

34. Fibrocartilage Tough Contains many collagenous fibers
Shock absorber for structures subjected to pressure
Found in intervertebral disks, knees, pelvic girdle
Function = support and fusion, and absorbs shocks.

35. Fibrocartilage

36. Bone Most rigid of connective tissues Mineral salts between cells
Matrix contains collagen
Supports, protects body structures
Houses marrow (where blood cells form)
Stores calcium, phosphate
Matrix is deposited in layers called lamellae around osteonic canals
Osteocytes in lacunae
An osteon is osteocytes and matrix wrapped around an osteonic canal
Osteons contain blood vessels
Canaliculi are small tubes through which osteocyte cytoplasm extends

37. Bone

38. Blood Transport Matrix=plasma Red blood cells White blood cells
Platelets
Blood cells float in plasma, formed in bone marrow

39. Blood

40. Connective Tissue Summary

41. BODY MEMBRANES 1
Epithelial Membranes = epithelial layer of cells plus the underlying connective tissue.
Three Types: Mucous membranes
2. Serous membranes
3. Cutaneous membranes

42. Mucous membranes
Mucous membrane = mucosa; it lines cavities that open to the exterior, such as the GI tract.
The epithelial layer of the mucous membrane acts as a barrier to disease organisms.
The connective tissue layer of the mucous membrane is called the lamina propria.
Found as the lining of the mouth, vagina, and nasal passage.

43. Serous membranes
Serous membrane = serosa, membrane lines a body cavity that does NOT open to the exterior and it covers the organs that lie within the cavity. a. pleura = lungs b. pericardium = heart c. peritoneum = abdomen
The serous membrane has two portions: 1. parietal portion = lining outside the cavity visceral portion = covers the organ. .

44. Serous membranes 2
Serous membranes epithelial layer secretes a lubricating SEROUS FLUID, that reduces friction between organs and the walls of the cavities in which they are located.
The serous fluid is named by location:
Pleural fluid is found between the parietal and visceral pleura of the lungs.
Pericardial fluid is found between the parietal and visceral pericardium of the heart.
Peritoneal fluid is found between the parietal and visceral peritoneum of the abdomen.

45. BODY MEMBRANES

46. BODY MEMBRANES

47. BODY MEMBRANES