1. Tissue Repair

2. Tissue Repair
Wound healing
Two ways:
Regeneration: replace destroyed tissue by same kind of cells

3. Tissue Repair
Wound healing
Two ways:
Regeneration: replace destroyed tissue by same kind of cells
Fibrosis: form scar tissue (dense fibrous connective tissue)
Depends on:
Type of tissue damaged
Severity of injury

4. Steps to Tissue Repair:

5. 1. Inflammatory Reaction
capillaries dilate bringing more WBC’s and clotting factors
clot forms and prevents loss of blood
surface dries forming a scab

6. 2. Granulation tissue forms
Delicate pink tissue with new capillaries
Connective tissue produces collagen fibers
Epithelial cells multiply over granulation tissue

7. 3. Surface epithelium regenerates
Surface epithelium thickens
Fibrous tissue matures – forms scar tissue

8. Regenerative Capacity of Different Tissues
Extremely Well
Moderate
Weak
Virtually None
(mostly scar tissue)
Skin epidermis
Mucous membranes
Fibrous connective
Blood
Bones
Smooth muscle
Tendons, ligaments
Skeletal muscle
Cartilage
Cardiac muscle
Nervous tissue

9. Tissue Origin

10. 3 Primary Germ Layers ectoderm mesoderm endoderm
Tissues originate from the 3 primary germ layers:
ectoderm
mesoderm
endoderm

11. 1. Ectoderm -
Nervous
Epidermis

12. 2. Mesoderm -
Muscle
Connective tissue
Bone

13. 3. Endoderm -
mucosa (GI tract)
glands
mucosa (GI tract)
glands

14. How Tissue Changes
Occurs with age

15. Tissue Changes epithelium thins collagen (a protein) decreases
easily penetrated
collagen (a protein) decreases
tissue repair becomes less efficient
bone, muscle, nerve degeneration
Causes:
due in part to a decrease in circulatory
efficiency
poor diet, also

16. The End