1. Histology
Connective Tissue

2. I. Connective Tissue A. General Characteristics
1. Composed of widely scattered cells that lie within a large amount of nonliving intercellular material. (Living cells surrounded by a matrix)

3. Major Cell Types Fibroblasts
Produce fibers by secreting protein into the matrix of the connective tissue
Macrophages
Comes from WBC and carries out phagocytosis. Important for defense against infection
Mast cells- located near blood vessels. They release the following:
Heparin- prevents blood clotting
Histamine- promotes some of the reactions with inflammation and allergies, such as asthma and hay fever.

4. Macrophage • Elastic fiber • Reticular fiber Fibroblast Mast cell
Figure 4.7 Areolar connective tissue: A prototype (model) connective tissue.
Cell types
Extracellular
matrix
Ground substance
Macrophage
Fibers
• Collagen fiber
• Elastic fiber
• Reticular fiber
Fibroblast
Lymphocyte
Fat cell
Capillary
Mast cell
Neutrophil

5. General Characteristics (cont.)
2. It functions mainly to support other body structures. It is the glue that keeps other tissues and organs in place

6. Different Tissue Types

7. Connective Tissue- Characteristics
3. Cells of connective tissue are of two types:
a. one produces and maintains intracellular material
b. the other protects the body from infection

8. Connective Tissue- Characteristics
4. The intracellular material that is produced is composed of a mixture of:
a. ground substance—these two things are known as ground tissue:
1. sugar-protein molecules
2. interstitial fluid
b. several types of protein fibers

9. Connective Tissue- Characteristics
5. Types of protein fibers
a. Collagenous fibers
1. Most abundant type of protein fiber in the intercellular material
2. They are thick wavelike strands of a protein called collagen, which is flexible but has great tensile strength (resists stretching).
3. Collagen is the most abundant protein in the body.

10. Connective Tissue- Characteristics
5. Types of protein fibers (cont.)
a. Collagenous fibers
4. Collagen is used extensively in the body for tissue repair.
a. main component of scar tissue that forms over a wound during healing
b. scar tissue does not stretch very much but it binds the skin together very well.
5. Where do you find them?
a. Tendons
b. In organs that must remain stationary in the body cavity.

11. Importance of Collagen and Elastin for our skin
As we age, it is believed that collagen begins to deteriorate and causes the skin to become thinner and eventually sag.
Elastin is similar to collagen but is a more stretchable protein that maintains the skin's elasticity.
The two proteins together permit the skin to stretch, then regain its original shape. With age, the skin's elastin breaks down and causes wrinkles.

12. What do you think?
Products claim to include collagen which will retexturize your
Skin making it more resilient and younger looking. Does this
Make sense?

13. SCAM!!!!!
Collegen molecules are way too large to penetrate the skin. Therefore dry skin may look moisturized, but won’t last. All you’re really getting is

14. Name the tissue, location AND function correctly!!!
Name That Tissue!!!
Name the tissue, location AND function correctly!!!

15. Tissue 1

16. Tissue 2

17. Tissue 3

18. Ehlers-Danlos Syndrome

19. Types of protein fibers (cont.)
b. Elastic fibers
1. Second type of protein fiber in the intracellular material, and are composed of the protein elastin
2. Elastin
a. It is not as strong as collagen and forms thinner fibers.
b. It has important properties of:
1. Elasticity
2. Extensibility
c. Locations- skin, lungs, blood vessels

20. Types of protein fibers (cont.)
c. Reticular fibers
1. They are composed of the protein called reticulin.
2. Reticulin
a. Resists physical stress despite its thin, branching shape.
b. In most connective tissues, reticular fibers are not abundant.

21. Connective Tissue- Characteristics
6. An important characteristic of connective tissue (except in cartilages) is the presence of blood vessels that pass through the intracellular material, it is a vascular tissue.
a. The ample blood supply provides the tissue with important capabilities for:
1. Growth
2. Repair

22. Connective Tissue/ Vascular Tissue
b. Connective tissue is the first tissue to be formed when an organ of the body is damaged.
c. Scar tissue
a. connective tissue that is rich in:
1. Collagen
2. Without elastic fibers

23. B. Connective Tissue Types
1. There are several types of connective tissues in the body.
2. They are distinguished on the basis of:
a. the density of proteins in their intracellular material
b. the nature of the cells that produce the intracellular material

24. Connective Tissue Types
3. They can be classified from the most rigid to the softest:
a. Bone
b. Cartilage
c. Dense connective tissue
d. Loose connective tissue
e. blood

25. Connective Tissue Types
Bone Connective Tissue
1. Osseous Tissue – another name for bone
Intracellular material is filled with mineral salts and collagenous fibers, providing it with a hard and durable structure that exceeds that of all other tissues. This dense material is called the matrix.
a. Two types of mineral salts
Calcium phosphate
Calcium carbonate
. Protection & Support

27. c. Two types of bone tissue:
1. Compact bone
a. Densely packed with mineral salts and collagen
b. In the outer layer of compact bone there is no ostenic canals, and lamella form a solid matrix

29. c. Two types of bone tissue:
2. Spongy Bone
a. Is not densely packed as that of compact bone
b. Contains spaces that are filled with blood-forming tissue, called red marrow
c. Spongy bone tissue forms the interior of bones

31. Flow Chart of Compact bone
Osteons
Osteocytes
Lacuna
Surrounded by hard matrix

32. Flow Chart (cont.)
1. Lamellae- Thin orderly layers that form concentric circles that encircle osteonic canals.
2. Haversian(Osteonic) Canals- Bone canals where blood vessels go through the bone
3. Osteocytes- bone cells that maintain the matrix. Found embedded within chambers. These are fed by blood vessels that penetrate the hard matrix. They obtain nourishment by diffusion.

33. Flow chart (cont.)
4. Lacunae- Chambers or cavities where osteocytes are found
5. Canaliculi- tiny channels where nutrients diffuse across the barrier formed by the lamellae

34. Connective Tissue Types
5. Cartilage Connective Tissue
a. Cartilage is less hard and more flexible than bone.
b. It is found only in a few places in the body
c. It contains a very dense and firm intracellular material that is composed of many protein fibers within a thickened, gel-like ground substance, known as a matrix

35. Cartilage Connective Tissue
1. Chondrocytes – cartilage cells, maintains the matrix
2. Lacunae – small spaces or chambers where chrondrocytes are found.
3. Perichondrium – a vascular dense connective tissue surrounding the cartilage.

36. Cartilage Connective Tissue
d. Types of Cartilage connective tissue
1. Hyaline cartilage
a. Most abundant cartilage
b. Abundance of collagen fibers hidden by a rubbery matrix appears bluish white, almost opaque- Hyaline means glass
c. The chondrocytes of Hyaline cartilage, which are embedded within an lacunae, are sparsely distributed throughout the extensive matrix

37. Hyaline cartilage d. Location 1. Upper part of the respiratory tract
2. Ends of bones where it forms moveable joints
3. At the end of the ribs
4. Skeleton of the fetus
5. Precedes bone formation in most bones of a growing child

38. Hylaine Connective Tissue

39. Types of Cartilage Connective Tissue
2. Elastic cartilage
a. Yellowish cartilage characterized by the presence of elastic fibers that dominate the matrix
b. A firm but flexible tissue
c. This type of cartilage is found where a structure with elasticity is desired.
1. Ears
2. End of the nose
3. The small lid over the opening of the larynx in the throat called the epiglottis

40. Elastic Cartilage Tissue

41. Types of Cartilage Connective Tissue
3. Fibrocartilage
a. Consists of a solid but flexible matrix characterized by the predominance of thick collagenous fibers.
b. Location
1. Knee – shock absorber
2. Intervertebral disks – padded joints

42. Fibrocartilage Connective Tissue

43. e. Dense connective tissue (dense fibrous tissue)
1. Two types of dense connective tissue
a. Dense irregular connective tissue
1. Fibers are not in parallel arrangement, but rather branch extensively to form a dense matting of protein.
2. Minimal amount of ground tissue
3. Fibroblasts are distributed randomly throughout the tissue.
4. Location
a. Deep layer of the skin called the dermis.
b. forms an external wrapping around bones and cartilage.

44. 1. Two types of dense connective tissue (cont.)
b. Dense regular connective tissue
1. Contains tissue densely packed fibers that extend parallel to each other.
2. Fibroblasts are distributed in a linear fashion beside groups of fibers
3. Very little ground tissue
4. Location
a. Resists the forces of physical stress
b. Tendons and ligaments

45. Dense Fibrous Connective Tissue

46. Loose Connective Tissue
f. Loose connective tissue(Areolar tissue)
1. They are softer and have more cells and fewer fibers than any other connective tissue type. (Areolar means small open space)
2. Has all three fibers, which are in a loose, disorganized network surrounded by a fluid ground substance. This provides a semi fluid material that has the consistency of a soft gel.

47. Loose Connective Tissue (cont.)
3. Small number of cells
a. Fibroblasts
b. Macrophages – phagocytic white blood cells
4. Function
1. Cushions and protects the body organs it wraps
2. Universal packing tissue
3. Connective tissue glue because it helps to hold the internal organs together and in their proper position
4. When a body region is inflamed, the areolar tissue in the area soaks up the excess fluid like a sponge and the area swells and becomes puffy, a condition called edema.

48. Loose connective tissue (cont.)
4. Location
a. found between the skin and muscle layers of the body
b. surfaces of most organs
c. filling in spaces between organs and other body parts

49. Loose Connective Tissue

50. Loose Connective Tissue (cont.)
g. Adipose Connective Tissue (Fat)
1. Large spherical cells containing a deposit of fat.
2. Commonly called fat.
3. Function
a. Stores energy as fat, forms an insulating padding between organs, and acts as a shock-absorbing cushion.
b. The fat stored within adipose cells is in the form of molecules called triglycerides.

51. Adipose Connective Tissue
4. Location
a. Padding around the kidneys
b. Cushions the eyeballs in the sockets
c. Hips
d. Breasts

52. Adipose Connective Tissue

53. Connective Tissue h. Blood Forming Tissue and Blood
1. In a liquid state, the cells are suspended in a liquid extracellular matrix
2. Two types of liquid connective tissue:
Blood
Lymph
3. The tissue contains basically three types of components:
a. stem cells that produce blood cell
b. newly formed blood cells that are in the process of maturing
c. a small amount of protein

54. Blood-forming Tissue and Blood
a. A type of connective tissue
b. The living cells are formed elements and surrounded by a fluid matrix known as plasma
c. The fibers of the matrix are dissolved protein molecules that become visible during clotting.

55. Blood (cont.) d. Function
1. transportation vehicle for the cardiovascular system
a. Respiratory gases
b. Nutrients
c. Wastes
d. Many other substances

56. Blood-forming tissue and Blood
d. There are two types of blood-forming tissue.
1. occurs inside cavities within spongy bone and is called red marrow
a. red blood cells
b. white blood cells
c. platelets

57. Two Types of Blood forming Tissue (cont.)
2. Lymphoid tissue
a. Location
1. Lymph nodes
2. Tonsils of the throat
3. Spleen 4. Thymus of children

58. Lymphoid Tissue (cont.)
b. Function
1. It is the maturation site of two types of white blood cells
a. lymphocytes
b. monocytes

59. Blood Connective Tissue