1. Chapter 3 Tissues

2. Body Tissues Cells are specialized for particular functions Tissues
Groups of cells with similar structure and function
Four primary types
Epithelium - covering
Connective tissue - support
Nervous tissue - control
Muscle tissue - movement

3. Overview Of Tissues & Functions
1. EPITHELIAL
2. CONNECTIVE
3. MUSCULAR
4. NERVOUS

4. Overview Of Tissues & Functions
1. Epithelial Tissues Functions
Covers exposed surfaces
Lines internal passages
Forms glands
Provide physical protection
Control permeability
Provide sensation
Produce specialized secretions (glandular epithelium)

5. Overview Of Tissues & Functions
2. Connective Tissues Functions
. * Fills internal spaces
Supports other tissues
Transports materials
Stores energy

6. Overview Of Tissues & Functions
3. Muscular Tissues Functions .
Specialized for contraction
Skeletal muscle, heart muscle, and walls of hollow organs

7. Overview Of Tissues & Functions
4. Neural Tissues Functions .
Carries electrical signals from 1 part of the body to another

8. The Epithelial Tissue Epithelia: layers of cells covering internal or external surfaces

9. Epithelial Tissues Found in different areas Functions: Protection
Absorption
Filtration
Secretion
Found in different areas
Body coverings
Body linings
Glandular tissue

10. Epithelium Characteristics
Cells fit closely together
Avascular (have no blood supply)
Regenerate easily if well nourished

11. Classification of Epithelium
Number of cell layers
Simple – one layer
Stratified – more than one layer
Figure 3.17a

12. Classification of Epithelium
Shape of cells
Squamous – flattened, like fish scales
Cuboidal – cube-shaped
Columnar – column-like
Figure 3.17b

13. Classes of Epithelia

14. Simple Epithelium Single layer of cells
Usually forms membranes or lines tracts
Simple Squamous
Simple cuboidal
Simple columnar
Figure 3.18a

15. Glandular Epithelium
Gland – one or more cells that secretes a particular product
Fun Fact: Secretion: typically contains protein molecules in an aqueous fluid

16. Glandular Epithelium Two major gland types
Endocrine gland ex: thyroid gland, pituitary gland
Ductless
Secretions are hormones into interstitial fluid
Exocrine gland ex: enzymes entering digestive tract, perspiration on the skin, tears in the eyes, & milk from mammary glands
Empty secretions through ducts to the epithelial surface
Include sweat and oil glands

17. Structural classes of exocrine glands
You don’t have to know, but it’s fun to be smart! Structure of Multicellular Exocrine Glands
Structural classes of exocrine glands
Figure 4–7 (1 of 2)

18. You don’t have to know, but it’s fun to be smart
You don’t have to know, but it’s fun to be smart! Structure of Multicellular Exocrine Glands
Figure 4–7 (2 of 2)

19. The Connective Tissue

20. Connective Tissue Found everywhere in the body
Includes the most abundant and widely distributed tissues

21. Connective Tissue Functions
Binds body tissues together
Provides protection
Have no contact with environment
Connect epithelium to the rest of the body
Transport materials (blood)
Supports the body
Provide structure (bone)
Store energy (fat)

22. Connective Tissue Characteristics
Variations in blood supply
Some tissue types are well vascularized
Some have poor blood supply or are avascular

23. Extracellular Matrix
- The extracellular components of connective tissues (fibers and ground substance)
majority of cell volume
determines specialized function
Non-living material that surrounds living cells

24. Extracellular Matrix 2. Fibers Produced by the cells Three types
Two main elements
1. Ground substance – mostly water along with adhesion proteins and polysaccharide molecules
2. Fibers
Produced by the cells
Three types
Collagen fibers
Elastic fibers
Reticular fibers

25. *Fibroblasts The most abundant cell type:
-secrete proteins and hyaluronan (cellular cement)

26. Classification of Connective Tissues
Connective tissue proper:
connect and protect
Fluid connective tissues:
transport
Supportive connective tissues:
structural strength

27. Fibers in Connective Tissue Proper
Collagen fibers:
most common fibers in CTP
long, straight, and unbranched
strong and flexible
resists force in 1 direction
e.g., tendons and ligaments

28. Fibers in Connective Tissue Proper
Reticular fibers:
network of interwoven fibers
strong and flexible
resists force in many directions
stabilizes functional cells and structures
e.g., sheaths around organs

29. Fibers in Connective Tissue Proper
Elastic fibers:
contain elastin
branched and wavy
return to original length after stretching
e.g., elastic ligaments of vertebrae

30. Connective Tissue Types (1 of 4)
Bone (osseous tissue)
For weight support
Composed of:
Bone cells in cavities
Hard matrix of calcium salts
Large numbers of collagen fibers
Function: Used to protect and support the body
Figure 3.19a

31. Connective Tissue Types (2 of 4)
CARTILAGE
gel-type ground substance
for shock absorption and protection
Elastic cartilage
Example: supports the external ear
Support soft tissues and body weight
Provides elasticity

32. Connective Tissue Type (3 of 4)
Dense connective tissue
Main matrix element is collagen fibers
Cells are fibroblasts
Examples
Tendon – attach muscle to bone
Ligaments – attach bone to bone
Figure 3.19d

33. Connective Tissue Types (4 of 4)
Blood
Blood cells surrounded by fluid matrix
Fibers are visible during clotting
Functions as the transport vehicle for materials
Figure 3.19h

34. Bones: Bone Cells: Osteocytes Bone Surface: Periosteum:
- arranged around central canals within matrix
- small channels through matrix (canaliculi) access blood supply
Bone Surface: Periosteum:
- covers bone surfaces

35. The Muscle Tissue

36. Muscle Tissue Function is to produce movement Three types
Skeletal muscle (1)
Cardiac muscle (2)
Smooth muscle (3)

37. Muscle Tissue Types (1 of 3)
1. Skeletal muscle:
Large body muscles responsible for movement
Can be controlled voluntarily
Cells attach to connective tissue
Cells are striated
Cells have more than one nucleus
Figure 3.20a

38. Muscle Tissue Types (2 of 3)
2. Cardiac muscle:
Found only in the heart
Function is to pump blood (involuntary)
Cells are striated
One nucleus per cell
Figure 3.20b

39. Muscle Tissue Types (3 of 3)
3. Smooth muscle
Involuntary muscle
Surrounds hollow organs
Attached to other smooth muscle cells
No visible striations
One nucleus per cell
Figure 3.20c

40. Nervous Tissue Neurons and nerve support cells
Function is to send impulses to other areas of the body
rapidly senses internal or external environment
Irritability- ability to respond to stimuli
Conductivity – able to conduct impulses
Figure 3.21

41. Nervous Tissue
Neural tissue is concentrated in the central nervous system:
brain
spinal cord
Figure 3.21

42. Tissues Injury and Repair
Cells restore homeostasis with 2 processes:
1. Inflammation (1): the tissue’s first response to injury
Signs: Swelling, redness, heat, pain,
Triggered by: Inflammation or Infection
Chemicals released
White blood cells clean up

43. Tissues Injury and Repair
When the injury or infection is cleaned up or healing (regeneration (2)) begins
Fibroblasts move into necrotic area:
lay down collagen fibers
to bind the area together (scar tissue)
New cells migrate to area

44. Tissue Repair Determination of method Regeneration Fibrosis
Type of tissue damaged
Severity of the injury
Regeneration
Replacement of destroyed tissue by the same kind of cells
Fibrosis
Repair by dense fibrous connective tissue (scar tissue)

45. Regeneration of Tissues
Tissues that regenerate easily
Epithelial tissue
Fibrous connective tissue and bone
Tissues that regenerate poorly
Skeletal muscle
Tissues that are replaced largely with scar tissue (*Do not regenerate)
Cardiac muscle cells
Nervous tissue (neurons) within the brain & spinal cord

46. Developmental Aspects of Tissue
With old age there is a decrease in mass and viabililty in most tissues
Speed and efficiency of tissue repair decreases with age, due to:
slower rate of energy consumption (metabolism)
hormonal alterations
reduced physical activity

47. Developmental Aspects of Tissue
Chemical and structural tissue changes:
thinning epithelia and connective tissues
increased bruising and bone brittleness
joint pain and broken bones
cardiovascular disease
mental deterioration

48. #1 Let’s Review Real Quick:
Tissues
Organized into 4 specialized cells:
Epithelial tissue
Connective tissue
Muscular tissue
Nervous tissue

49. #2 Review Division of epithelial tissues into epithelia and glands:
epithelia as avascular barriers for protection
glands as secretory structures

50. #3 Review Classification of epithelial cells:
by number of cell layers (simple or stratified)
by shape of cells (squamous, columnar or cuboidal)

51. #4 Review The functions of connective tissues: structure transport
protection
support
connections
energy storage

52. #5 Review The structure of connective tissues: matrix ground substance
protein fibers

53. #6 Review The classification of connective tissues:
connective tissue proper (cell types, fiber types, and embryonic connective tissues)
fluid connective tissues (blood and lymph, fluid transport systems)
supporting connective tissues (cartilage and bone)

54. #7-8 Review
The 3 types of muscle tissues (skeletal, cardiac, and smooth)
The classification of muscle tissues by striation, nucleation, and voluntary control

55. #9-10 Review
Tissue injuries and repair systems (inflammation and regeneration)
The relationship between aging & tissue structure