1. Epithelial Tissue (pg 2)

2. Tissue = collection of cells that have similar
structure and function together as a unit

3. Tissue = collection of cells that have similar
structure and function together as a unit
Histology = Study of tissues

4. Epithelial Tissues
• Form the covering of all body surfaces,
line body cavities and organs, and form
glands

5. Epithelial Tissues
• Form the covering of all body surfaces,
line body cavities and organs, and form
glands
• Cells are tightly packed

6. Epithelial Tissues
• Form the covering of all body surfaces,
line body cavities and organs, and form
glands
• Cells are tightly packed
• One free surface

7. Epithelial Tissues
• Form the covering of all body surfaces,
line body cavities and organs, and form
glands
• Tightly packed
• One free surface
• Avascular (no blood vessels)

8. Epithelial Tissues
• Form the covering of all body surfaces,
line body cavities and organs, and form
glands
• Tightly packed
• One free surface
• Avascular (no blood vessels)
• Regenerate quickly

9. Shapes
1. Squamous = flat cells, thin nuclei

10. Shapes
1. Squamous = flat cells, thin nuclei
2. Cuboidal = cubelike cells, spherical
central nuclei

11. Shapes
1. Squamous = flat cells, thin nuclei
2. Cuboidal = cubelike cells, spherical
central nuclei
3. Columnar = Tall narrow
cells, nuclei near bottom

12. Number of Layers
1. Simple = 1 layer

13. Number of Layers
1. Simple = 1 layer
2. Stratified = Multiple layers of cells.
Named according to the type of cells at
the free surface of the tissue

14. Number of Layers
1. Simple = 1 layer
2. Stratified = Multiple layers of cells.
Named according to the type of cells at
the free surface of the tissue
3. Pseudostratified = appears to be multiple
layers, but is really only 1 layer

16. Glandular Epithelium
• Exocrine glands = secrete products onto a
surface via a duct

17. Glandular Epithelium
• Exocrine glands = secrete products onto a
surface via a duct
• Can be unicellular (goblet cells) or
multicellular

18. Exocrine Glands
Classified according to STRUCTURE
1. Simple: duct has no branches
2. Compound: duct has branches

19. Exocrine Glands
Classified according to STRUCTURE
1. Simple: duct has no branches
2. Compound: duct has branches
3. Tubular: gland has the same diameter as the
duct
4. Acinar (Alveolar): gland is saclike

21. Exocrine Glands
Classified according to SECRETIONS
1. Merocrine: fluid released by exocytosis
Example: salivary and pancreatic glands

22. Exocrine Glands
• Classified according to SECRETIONS
1. Merocrine: fluid released by exocytosis
Example: salivary and pancreatic glands
2. Apocrine: small portion of cell is pinched off
Example: Mammary glands

23. Exocrine Glands
• Classified according to SECRETIONS
1. Merocrine: fluid released by exocytosis
Example: salivary and pancreatic glands
2. Apocrine: small portion of cell is pinched off
Example: Mammary glands
3. Holocrine: Cells fill with product and rupture
Example: Sebaceous (oil) glands