1. Chapter 4.1 (Human Anatomy)
Epithelial Tissue
Chapter 4.1 (Human Anatomy)

2. Histology is the branch of anatomy that studies the structure of animal tissue on a microscopic level.

3. What is a tissue?
A group of cells that all perform the same specific function
Example: cardiac, muscle, or nerves

4. 4 Types of Tissues
1) Epithelial Tissue – covers body surfaces and organs, lines body cavities
2) Connective Tissue – binds and supports body parts

5. 3) Muscular Tissue – contracts producing movement
4) Nervous Tissue – responds to stimuli and transmits nerve impulses

6. Epithelial Tissue Tightly packed cells
Readily divides (mitosis) producing new cells to replace old or damaged cells
Lacks blood vessels
Exists on the skin and on the surface of organs, blood vessels, and body cavities

7. Function:
- Externally – protects body from drying out, injury, and bacterial invasion
- Internally – protects, sweeps up impurities, secretes mucus, absorbs

8. Covers surfaces and lines cavities
Has a free surface
Other surface attached to underlying tissue by the basement membrane
Free Surface
Nucleus
Basement membrane
Cytoplasm
Free Surface
Nucleus
Basement membrane

9. Simple Epithelial Tissue – composed of a single layer of cells
Stratified Epithelial Tissue – composed of 2 or more layers of cell

10. Types of Epithelial Tissues
1] Squamous Epithelium: simple and stratified
2] Cuboidal Epithelium
3] Columnar Epithelium
4] Pseudostratified Epithelium
5] Transitional Epithelium

13. Squamous Epithelium 2 types of squamous epithelium:
* Simple Squamous Epithelium
* Stratified Squamous Epithelium

14. SIMPLE SQUAMOUS EPITHELIUM:
– Single layer of flattened cells
– Function: secretion, absorption, and filtration
– Location: lines the lungs, blood vessels and heart

15. Simple Squamous Epithelium
Cytoplasm
Nucleus
Simple Squamous Epithelium

16. STRATIFIED SQUAMOUS EPITHELIUM
– Many layers of flattened cells
– Function: protection
– Location: outer layer of skin, lining the various orifices of the body

17. Stratified Squamous Epitlelium

18. Cuboidal Epithelium Location Function Glands secretion Kidney tubules
Simple Cuboidal Epithelium:
- single layer of cube-shaped cells attached to a basement membrane
Stratified Cubiodal Epithelum: two or more layers of cube-shaped cells
Location
Function
Glands
secretion
Kidney tubules
Secretion & absorption

19. Simple Cuboidal Epithelium
Basement membrane
Nucleus
Free Surface
Simple Cuboidal Epithelium

20. Simple Columnar Epithelium
Composed of cells that are longer than wider
Nucleus found in the lower half of the cell
Location
Function
Digestive organ
Absorption
Uterine tubes
Propel egg to uterus

21. Free Surface
Nucleus
Basement membrane

22. Pseudostratified Epithelium
Cells appear to be layered due to irregularly placed nuclei but each cell touches the basement membrane
May contain cilia – aids in movement of particles
Function: protection, secretion, movement of mucus and sex cells
Location: respiratory tract, reproductive tract

23. Pseudostratified Epithelium
Cilia
Nucleus
Basement membrane
Pseudostratified Epithelium

24. Transitional Epithelium
Tissue that changes in response to tension
Found in organs that need to stretch
Location: urinary bladder, ureters, urethra

25. Transitional Epithelium
Basement membrane
Nucleus
Free Surface
Transitional Epithelium