1. Epithelial Tissue
Anatomy

2. What are tissues?
Groups of cells that are similar in structure and perform a common function
Histology: the study of tissues

3. Epithelial Tissue Covers body surface Lines a body cavity
Forms boundaries between different environments
Skin: lies between inside/outside of body
Epithelium in bladder: separates bladder and urine

4. Epithelial Forms outer layer of skin
Lines open cavities of cardiovascular, digestive and respiratory systems

5. Characteristics of Epithelium
Cellularity: closed packed cells (little to no extracellular material)
Specialized contacts: continuous sheets

6. Characteristics of Epithelium
Polarity:
apical surface (surface exposed to body exterior/cavity)
basal surface/lamina (opposite the apical, supporting)

8. Characteristics of Epithelium
Supported by connective tissue:
Reticular lamina (contains collagen fibers)
Basement membrane: reticular lamina with the basal lamina, reinforces, resists stretching/tearing/defines boundary

10. Characteristics of Epithelium
Avascular but innervated
Has nerve fibers but does not contain blood vessels
Nourished by substances diffusing into layer from lower layers

11. Characteristics of Epithelium
Regeneration
High regeneration capacity

12. Classification of Epithelia
Simple
Stratified
Squamous
Cubodial
Columnar

15. Simple squamous epitheial
Single layer of flattened cells
Disc shape central nuclei
Allows passage of materials (diffusion/filtration), secretes serosa
Kidney glomeruli, air sacs of lungs, linging of heart, blood vessels, lymphatic vessels

17. Simple cubodial epithelium
Single layer of cube like cells with large central nuclei
Secretion/absorption
Kidney tubules, ducts of glands, ovary surface

19. Simple columnar epithelial
Single layer of tall cells with oval nuclei, cilia, contrain mucus secreting cells (goblet cells)
Absorption, secretion, propel secretion (mucus, enzymes)
Digestive tract, gallbadder, uterus

21. Stratified squamous epithelium
Thick, basal cells are cubodial/columnar, surface cells are flat, surface cells full of keratin (dead)
Protection
Mouth, esophagus, skin, dry membranes

23. http://classes. midlandstech. edu/carterp/Courses/bio210/chap04/chap04