1. The Tissue Level of Organization Lecture Outline
Chapter 4
The Tissue Level of Organization
Lecture Outline

2. INTRODUCTION
A tissue is a group of similar cells that usually have a similar embryological origin and are specialized for a particular function.
Histology: The study of tissues
Pathologists: physicians who specialize in laboratory studies of cells and tissues, aid other physicians in making diagnoses; and they perform autopsies.
Principles of Human Anatomy and Physiology, 11e

3. TYPES OF TISSUES AND THEIR ORIGINS
1. Epithelial Tissue
2. Connective Tissue
3. Muscle Tissue
4. Nervous Tissue

4. Epithelial Tissue 1. Epithelial Tissue
covers body surfaces, lines hollow organs, body cavities, and ducts; and forms glands.
Principles of Human Anatomy and Physiology, 11e

5. Connective Tissue 2. Connective Tissue
protects and supports the body and its organs, binds organs together, stores energy reserves as fat, and provides immunity. (Fat, Blood, Tendons)
Principles of Human Anatomy and Physiology, 11e

6. Muscle Tissue 3. Muscle Tissue
is responsible for movement and generation of force.
Examples: Skeletal, Cardiac, Smooth (stomach, intestine)
Principles of Human Anatomy and Physiology, 11e

7. TYPES OF TISSUES AND THEIR ORIGINS
4. Nervous Tissue
initiates and transmits action potentials (nerve impulses) that help coordinate body activities.
Principles of Human Anatomy and Physiology, 11e

8. CELL JUNCTIONS
Cell junctions are points of contact where 2 tissues meet.
Depending on their structure, cell junctions may serve one of three functions.
Tight cell junctions form
fluid-tight seals between cells.
2. Desosome cell junctions anchor
cells together or to
extracellular material.
3. Gap Junctions act as channels,
which allow ions and molecules
to pass from cell to cell within
a tissue.

9. TISSUE REPAIR: RESTORE HOMEOSTASIS
Tissue repair is the process that replaces worn out, damaged, or dead cells.
Different tissues can be repaired in different ways:
Epithelial cells are replaced by the division of stem cells.
Connective tissue: Bone is easily replaced and repaired, cartilage is not (think torn ACL)!
Muscle cells have a poor capacity for renewal.
Nervous tissue has the poorest capacity for renewal. (think spinal cord injuries)
Principles of Human Anatomy and Physiology, 11e

10. Tissue Repair: Restoring Homeostasis
Fibrosis is the process of scar formation.
Scars are made up of collagen and other proteins. Scar tissue on important organs causes them to function incorrectly.
Principles of Human Anatomy and Physiology, 11e

11. Cystic Fibrosis
Cystic Fibrosis: a disease passed down through families that causes thick, sticky mucus to build up in the lungs, digestive tract, and other areas of the body. It is one of the most common chronic lung diseases in children and young adults. It is a life-threatening disorder.
Principles of Human Anatomy and Physiology, 11e

12. Adhesions
Adhesions are formed when scar tissue from two tissues gets stuck to each other. This is painful and must be corrected by surgery.
Principles of Human Anatomy and Physiology, 11e

13. Tissue Engineering
New tissues grown in the laboratory (skin & cartilage)
Research in progress
insulin-producing cells (pancreas)
dopamine-producing cells (brain)
bone, tendon, heart valves, intestines & bone marrow

14. Conditions Affecting Tissue Repair
Nutrition
adequate protein for structural components
vitamin C for production of collagen & new blood vessels
Proper Blood Circulation
delivers O2 & nutrients & removes fluids & bacteria
With Aging
collagen fibers change in quality
elastin fibers fragment and abnormally bond to calcium
cell division and protein synthesis are slowed
Principles of Human Anatomy and Physiology, 11e

15. Sjogren’s Syndrome
Autoimmune disorder producing exocrine gland inflammation
Dryness of mouth and eyes, less saliva produced
20% of older adults show some signs
Females are affected 9 times more than men
Cannot be cured, but symptoms can be managed by using eye drops and chewing gum
Principles of Human Anatomy and Physiology, 11e

16. Systemic Lupus Erythematosus (SLE)
Commonly known as Lupus
Cause is unknown
Tissue throughout the body is damaged
Females 9:1 (1 in 2000 individuals)
Nonwhite women during childbearing years are most affected
Painful joints, ulcers, loss of hair, fever
Life-threatening if inflammation occurs in major organs --- liver, kidney, heart, brain, etc.
No cure, but some drugs can reduce symptoms
Principles of Human Anatomy and Physiology, 11e