1. Warm-Up What is a tissue? The study of tissues is called ______.
What are the 4 main types of tissues? (See the intro to Chapter 4 in textbook)

2. Warm-Up 1. 2. 3. 4. What type of epithelial cell is shown below?
Simple Columnar Epithelium
Pseudostratified Columnar Epithelium 3. 4.
Simple Cuboidal Epithelium
Stratified Squamous Epithelium

3. Tissue: The Living Fabric
Chapter 4
Tissue: The Living Fabric

4. Tissue: group of cells that are similar in structure and function
Histology: study of tissues
Types of Tissues:
Epithelium (covering)
Connective (support)
Muscle (movement)
Nervous (control)

5. Preparing tissues for microscopy
Specimen is fixed (preserved)
Cut into thin sections (slices)
Stained with colored dyes

6. Part I: Epithelial Tissue

7. Epithelial Tissue “epithe” = laid on, covering Structure:
Covering and lining epithelium
Glandular epithelium
Function:
Protection
Absorption
Filtration
Secretion

8. Special Properties Polarity
Apical surface = exposed free surface or edge (some with microvilli, cilia)
Basal surface = lower, attached surface
Specialized contacts
Fits close together to form continuous sheets

9. Special Properties Supported by connective tissue
Rests on basement membrane
No blood supply (avascular)
Rely on diffusion and underlying connective tissue for food/O2
Regeneration – Replace lost cells

10. Classification Two names = (# cell layers) + (shape of cells)
Cell Layers: simple or stratified
Shapes: squamous, cuboidal, or columnar

14. Simple Epithelium
Absorption, secretion, filtration
Very thin

15. Simple Epithelium

16. Simple Epithelium Simple squamous Filtration, rapid diffusion
Capillary walls, air sacs in lungs, kidney filtration
Serous membranes: slick layer lining ventral body cavity and its organs

17. Simple Epithelium Simple cuboidal Secretion & absorption
Lines ducts of glands (salivary), kidney tubules, ovary surface

18. Simple Epithelium Simple columnar Absorption and secretion
Lines digestive tract
Microvilli, cilia
Mucous membranes: lubricating mucus

19. Simple Epithelium Pseudostratified columnar
Rests on basement membrane – false impression (pseudo) of being multi-layered
Secretes or absorbs
Respiratory tract – cilia propels mucus from lungs

20. Stratified Epithelium
2+ layers, more durable
Main function = protect

21. Stratified Epithelium
Stratified squamous
Withstand abuse, friction
Esophagus, mouth, outer portion of skin

22. Stratified Epithelium
Stratified cuboidal
Usually 2 layers
Mainly in ducts of large glands (sweat, mammary, salivary)
Sweat Gland
Esophageal Gland

23. Stratified Epithelium
Stratified columnar
Thick, waterproof layer
Pharynx, male urethra, lining ducts

24. Transitional Epithelium
Able to change shape (cuboidal  squamous)
Lining of hollow urinary organs (bladder, ureter, urethra)
Stretches when filled with urine

25. Glandular Epithelium Gland: make and secrete a particular product
2 Types:
Endocrine gland: produce hormones secreted into tissue fluid or bloodstream
Exocrine gland: secrete products into ducts  onto body surfaces or body cavities
Eg. mucous, sweat, oil, saliva, bile

26. Exocrine Glands Unicellular Multicellular Mucus cells or goblet cells
Duct structure