Anatomy & Physiology Lecture Notes - Ch. 4 tissues - epithelium

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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/O
2
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