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

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

3. Chapter 4

4.  Tissue: group of cells that are similar in
structure and function
 Histology: study of tissues
Types of Tissues:
1. Epithelium (covering)
2. Connective (support)
3. Muscle (movement)
4. 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:
1. Covering and lining epithelium
2. Glandular epithelium
 Function:
 Protection
 Absorption
 Filtration
 Secretion

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

9. Special Properties
3. Supported by connective tissue
 Rests on basement membrane
3. No blood supply (avascular)
 Rely on diffusion and underlying connective
tissue for food/O2
3. 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