1. Connective Tissue
The most abundant and widely distributed type of tissue in the whole body.
General characteristics:
With the exception of 3 types, connective tissues have a great blood supply.
Reproduce quickly
Classified as being “connective” because at least 50% of the tissue is non-living.

2. Connective Tissue continued….
Function:
Designed to bind tissues together
Helps protect the body
Store energy in the form of fat
Transport materials throughout the body (blood, lymph)
2 main components of connective tissue:
Matrix
Cells

3. Matrix of Connective Tissue
A base material that contains protein fibers and is found between the cells of connective tissue.
Functions to support the cells of the connective tissue
Non-living
The structure of the matrix determines the characteristics of the connective tissue
Fibers are proteins found in the matrix that strengthen and support connective tissue.

4. Fibers in Connective Tissue
The properties of a connective tissue can change if the types/amounts of fibers in the matrix change.
Types of fibers:
Collagen- Very strong and slightly flexible and add strength to connective tissue
Elastic- Strong and very flexible fibers
Reticular- Strong and highly branching fibers that help form the framework of a connective tissue

5. “Ideal” Connective Tissue

6. Cells of Connective Tissue
Not all of the possible types are found in all connective tissues
Fibroblasts:
Make the fibers found in the matrix
Found in most connective tissues
Phagocytes:
Macrophages and neutrophils- Phagocytic cells that “eat and eliminate” foreign materials.

7. Cells of Connective Tissue continued…
Plasma cells:
Found in most connective tissues
Produce antibodies
Antibodies- Molecules that help protect us from foreign particles
Mast cells:
Found in all connective tissues
Release histamine
Histamine- Causes swelling because it signals for blood vessels to become more “leaky” and signals for blood to rush to an area

9. Skin
The next few slides will illustrate the process of inflammation. The skin forms a barrier to keep microorganisms out of the body.
Blood

10. Tissue Damaged
The inflammation process can begin if the skin or other tissues are damaged. *A pin penetrating into the skin can start an inflammation. *Bacteria may enter the body with the pin.

11. Histamine Released
Injured cells will release histamine. *Histamine will diffuse away from the injured cells.

12. Capillary More Permeable
Plasma Leaks Out
Histamine will cause capillaries to become more permeable. *This will allow plasma to leak out of the blood.

13. Capillary More Permeable
Antibodies Leak Out
Antibodies will also leave the blood capillary*.

14. Capillary More Permeable
WBCs Leave
White blood cells will leave the blood by diapadesis*.

15. Wall of Fibrin Forms
The plasma in the injured area will clot to form a wall of fibrin*.

16. Pus Forms
Pus forms within the fibrin wall. The pus is composed of serum, white blood cells and bacteria. The pus will drain and scar tissue will form. At this point the injury to the body has been controlled and homeostasis will be restored. Without the inflammation process the injury could spread. For example, bacteria could spread throughout the body and cause death.

18. Cells of Connective Tissue continued…
Adipocytes:
Found in some connective tissues
Contain fat

19. Types of Connective Tissue
There are 6 types of mature connective tissue. They include: loose connective tissue, dense connective tissue, cartilage, bone tissue, blood tissue and lymph.

20. Loose Connective Tissue
Loosely arranged fibers in the matrix.
Areolar- Loose arrangements of collagen, elastic and reticular fibers present in the matrix
Location: In and around every body structure so is often called the “packing material” of the body.
Function: Binds structures together, provides strength (collagen), and provides flexibility (elastic)
Adipose- Lipids (fats) present in the matrix
Location: Below the skin and surrounding organs
Function: Stores fat, insulates against heat loss, and protects organs

23. Loose Connective Tissue
Reticular- Loose arrangements of reticular fibers and reticulocytes in the matrix
Reticulocytes are a type of fibroblast that specifically secrete lots of reticular fibers.
Function: Form the framework for larger organs (like the framework of a house)

25. Dense Connective Tissue
Large amounts of thick, dense fibers and fewer cells than loose connective tissue
Dense regular- Parallel bundles of collagen fibers present in the matrix
Connects muscle to bone (tendon) or bone to bone (ligament)
Can resist lots of force along the length of the fibers
A force against the fibers can tear them (torque)
Poor blood supply so it takes a long time to heal

27. Dense Connective Tissue
Dense irregular- Random arrangements of collagen fibers present in the matrix.
Good blood supply
Makes up the dermis (middle layer) of the skin
Resists pulling forces in multiple directions

29. Dense Connective Tissue
Elastic: Freely branching elastic fibers present in the matrix.
Good blood supply
Makes up the wall of an artery
Allows a hollow structure to expand and recoil freely
This keeps blood moving along in arteries

31. Cartilage
Consists of a dense network of collagen and elastic fibers in a semi-solid matrix
Poor blood supply
Chondrin- Gel-like protein found making up the matrix of cartilage tissue
Types of cartilage
Hyaline
Cartilage cells (chondrocytes) suspended in a chondrin matrix.
Acts as a shock absorber
Covers the ends of bones at a joint

33. Types of cartilage continued…
Fibrocartilage
Large bundles of collagen fibers and few chondrocytes suspended in a chondrin matrix
Found in the knee meniscus and the disks between vertebrae
Acts as a shock absorber
Elastic cartilage
Elastic fibers and few chondrocytes suspended in a chondrin matrix
Found in the outer ear

36. Bone Characterized by a matrix composed of inorganic minerals.
Minerals are embedded in rings
Support and protect
Histology of bone will be explained later in the Bone unit

38. Blood Liquid connective tissue
Transports materials throughout the body
2 basic components:
Plasma-
55% of total blood
mostly water
supports the formed elements
Formed elements (cells)-
Erythrocytes- red blood cells- transport oxygen- outnumber white cells 700:1
Leukocytes- white blood cells- fight infection
Thrombocytes- platelets- cell fragments- help form blood clots

39. Lymph Liquid connective tissue
Located in lymphatic vessels- separate from blood vessels
No red blood cells nor platelets
Fights infection

41. Fluid Connective Tissue