1. Tissue Level of Organization
Tissues are groups of similar cells and extracellular material that carry out a common function.

2. 4 Types of Tissues epithelial tissue connective tissue muscle tissue
nervous tissue

3. Junctions There are five types of cell junctions: tight junctions
adherens junctions
Desmosomes
hemidesmosomes
gap junctions

4. Epithelial Tissue Lines every body surface and all body cavities.
Forms both the external and internal lining of many organs.
Composed of one or more layers of closely packed cells
Cells sit on basal surface (basement membrane)
Apical (upper) free surface
No blood vessels

6. Classification of Epithelium
Classified by arrangement of cells into layers
simple = one cell layer thick
stratified = many cell layers thick
pseudostratified = single layer of cells where all cells don’t reach apical surface
nuclei at found at different levels so it looks multilayered

8. Classification of Epithelium
Classified by shape of surface cells
squamous =flat
cuboidal = cube-shaped
columnar = tall column
transitional = shape varies with tissue stretching

9. Examples of Simple Squamous
Surface view of lining of peritoneal cavity
Section of intestinal showing serosa

10. Stratified Squamous Epithelium

11. Functions of Epithelial Tissue
Protection
Regulation of materials into and out of the organ or tissue
Produce secretions
Endocrine glands
Exocrine glands

12. Functions of Epithelial Tissue
Nerve endings detect changes in the external environment at their surface.
Continuously supply information to the nervous system concerning touch, pressure, temperature, and pain.

13. Endocrine Glands
Lack ducts and secrete their products directly into the interstitial fluid and bloodstream.
Hormones act as chemical messengers to influence cell activities elsewhere in the body.

14. Exocrine Glands
Duct secretes materials onto the surface of the skin or onto an epithelial surface lining an internal passageway.

15. Connective Tissue
Most diverse and microscopically variable of the tissues.
Designed to support, protect, and bind body structures together.
Rich blood supply – except cartilage

17. Basic Components of CT All CT share three basic components: cells
protein fibers
ground substance

18. Components of CT: Protein Fibers
Most contains protein fibers throughout the tissue.
Strengthen and support connective tissue.
Type and abundance of these fibers varies depending on function.

19. Components of CT: Protein Fibers
Three basic types of protein fibers:
collagen fibers are strong and stretch-resistant
elastic fibers are flexible and resilient
reticular fibers form an interwoven framework

21. Components of CT: Ground Substance
Cells and the protein fibers reside within a material called ground substance.
Nonliving material produced by the connective tissue cells.
Primarily consists of molecules composed of protein and carbohydrate and variable amounts of water.
May be viscous (blood), semisolid (cartilage), or solid (bone).

22. Functions of Connective Tissue
Physical protection
Support and structural framework
Binding of structures
Storage
Transport

23. 2 Broad Categories of CT Loose connective tissue
Dense connective tissue

27. Cartilage Network of fibers in rubbery ground substance
Avascular – slow to heal, no nerves
Resilient and can endure more stress than loose or dense connective tissue
Types of cartilage
hyaline cartilage
fibrocartilage
elastic cartilage

28. Supporting Connective Tissue
Cartilage
Hyaline
Fibrocartilage
Elastic
Bone
Compact
spongy

29. Fluid Connective Tissue
Blood
Lymph

30. Muscle Tissue skeletal muscle Striated, voluntary cardiac muscle
Striated, involuntary
smooth muscle
Not striated, involuntary .

31. Nervous Tissue
Neurons or nerve cells
Neuroglia or glial cells