1. The study of the tissues of the body
Lab 3 – Histology
The study of the tissues of the body

2. There are four tissue categories:
Epithelial Tissue
Connective Tissue
Nerve Tissue
Muscle Tissue
Histology is the study of tissues.

3. REVIEW

4. Epithelial tissue is composed of closely packed cells
Connective tissue is composed of a few cells surrounded by lots of extracellular matrix (fibers, fluid, minerals, etc.)
Epithelial Tissue
Connective Tissue

5. Questions to ask for identifying tissues
Epithelial tissue
Connective tissue

6. Objective 2: Connective Tissues

7. CONNECTIVE TISSUES – Locations
Most abundant tissue
Found everywhere except for body surfaces
Why not?

8. CONNECTIVE TISSUES – Functions
Bind
Support
Protect
Insulate
Transport

9. Connective tissue has:
Cells
Fibers
Ground substance
Areolar connective tissue The prototype of connective tissues: Other connective tissues contain variations in the amount or type of cells, ground substance &/or fibers as found in areolar connective tissue

10. Connective tissue is relatively cell poor Contains many different
cell types
Fibroblast
Adipocytes
Mast cells
Macrophage

11. Cell types
Fibroblasts (cytes)*- secret /maintain ground substance (connective tissue proper)
Chondroblasts (cytes)*- secret /maintain ground substance (cartilage)
Mast cells – secret histamine, heparin
Macrophages – phagocytes
Adipocytes – fat storage
Blasts secrete ground substance
Cytes maintain ground substance

12. Ground substance Fibers Interstitial fluid Proteoglycans – viscosity
Collagen fibers
Elastic fibers
Reticular fibers

13. Classes of Connective Tissue

14. Mesenchyme embryologic connective tissue
Note star-shaped cells
ground substance
cells
fibers

15. Connective Tissues Proper
Loose Connective Dense Connective
Areolar
Dense Regular
Adipose
Dense Irregular
Reticular

16. Loose Connective Tissue
Reticular
Areolar
Adipose
elastic fibers
collagen
fibers
adipocyte nucleus
adipocytes (vacuoles)
reticular cell
reticular fibers
ground substance
extracellular matrix
Note: Reticular tissue
also contains
mast cells
Note: Reticular fibers
not seen

17. Dense Connective Tissue
Dense Regular
Dense Irregular
Collagen fibers
Collagen fibers
Fibroblast nuclei
Fibroblast nuclei

18. Cartilage

19. Cartilage Hyaline Elastic Fibrocartilage matrix elastic fibers
collagen fibers
Chondrocytes inside Lacunae
Lacunae = “little lakes”

20. Tissue Comparisons
Adipose
Elastic Carilage
Reticular

21. Objective 3: Membranes

22. Serous Membrane Parietal peritoneum Parietal pleura Visceral
pericardium
Visceral
pericardium

23. Mucous Membrane Mucosa of nasal cavity Esophagus lining Trachea
lung bronchi
Mucosa of
digestive tract

24. Membranes are simple organs composed of 2 tissues: Epithelium tissue
Connective tissue
Serous Membrane
simple squamous epithelium
areolar connective tissue
Mucous Membrane
stratified squamous, pseudostratified columnar, or simple columnar epithelium
areolar connective tissue (lamina propria)

25. More in-depth information
E-Reserves
More in-depth information
&
Practice for identifying the tissues