This video covers the epithelial tissue

1. Tissues: Epithelial Tissue
GIDEON ROBERT UNIVERSITY
ANATOMY AND PHYSIOLOGY
NSWANA CHING’AMBU

2. Body Tissues
• Know
• 4 types of tissues
• Characteristics & functions of epithelial tissue
• Types & location of simple epithelium
• Types & location of stratified epithelium
• Glandular epithelium

3. Body Tissues
• Cells are specialized for particular functions
• Tissues
•Groups of cells with similar structure and
function
•Four primary types
A. Epithelial tissue
B. Connective tissue
C. Nervous tissue
D. Muscle tissue

4. Epithelial Tissues
• Found in different areas
• Body coverings
• Body linings
• Glandular tissue
• Functions
• Protection
• Absorption
• Filtration
• Secretion

5. Epithelium Characteristics
• Cells fit closely together
• Tissue layer always has one free
surface
• The lower surface is bound by a
basement membrane
• Avascular (have no blood
supply)
• Regenerate easily if well
nourished

6. Classification of Epithelium
1. Number of cell layers
i. Simple – one layer
ii. Stratified – more than
one layer

7. Classification of Epithelium
2. Shape of cells
i. Squamous – flattened
ii. Cuboidal – cube-shaped
iii. Columnar – column-like

8. Classification of Epithelium

9. Simple Epithelium
1. Simple squamous
epithelium
•Single layer of flat cells
•Allow materials to pass through
by diffusion & filtration, and
secretes and lubricate substances
• Lines air sacs and blood vessels
• Lines body cavities

10. Simple Epithelium
2. Simple cuboidal epithelium
• Single layer of cube-like cells
• Secrete and absorbs
• Common in glands and their ducts
• Forms walls
of kidney tubules
• Covers the ovaries

11. Simple Epithelium
3. Simple columnar epithelium
•Single layer of tall cells
•Absorbs, also secrete mucous
and enzymes
•Lines digestive tract

12. Simple Epithelium
4. Pseudostratified
columnar epithelium
• Single layer, but some cells
are shorter than others
• Often looks like a double cell
layer
• Sometimes ciliated, such as in
the respiratory tract
• May function in absorption or
secretion

13. Stratified Epithelium
1. Stratified squamous epithelium
• Cells at the free edge are flattened
• Found as a protective covering
where friction is common
• Locations
• Skin
• Mouth
• Esophagus
• Vagina

14. Stratified Epithelium
2. Stratified cuboidal epithelium
• Two layers of cuboidal cells
• Sweat, salivary & mammary glands
• Protective tissue
3. Stratified columnar epithelium
• Surface cells are columnar, cells underneath
vary in size and shape
• Male urethra & ducts of some glands
• Secretes & protects

15. Stratified Epithelium
4. Transitional epithelium
•Shape of cells depends upon
the amount of stretching
•Lines organs of the urinary
system, mostly urinary bladder
•Allow urinary organs to expand
and stretch

16. Glandular Epithelium
• Gland – one or more cells that
secretes a particular product
• Two major gland types
1. Endocrine gland
2. Exocrine gland

17. Glandular Epithelium
1. Endocrine gland
• Endocrine glands are ductless
• Secretions of endocrine glands are hormones

18. Glandular Epithelium
2. Exocrine gland
• Empty through ducts to the epithelial surface
• Include sweat and oil glands