1. Chapter 4 Tissues

2. Chapter 4… 4 Types of Tissues You will be able to:
Epithelium - covering
Connective tissue - support
Nervous tissue - control
Muscle tissue - movement
You will be able to:
State the function of each types of tissue.
Describe the locations of different types of tissue.
List the components of each type of tissue.

3. Today’s Lesson… We will learn about TISSUES.. Introduction to Tissues
Epithelial Tissues
Function
Location
Components and Structure

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

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

6. 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)

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

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

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

10. *KEY CONCEPT*
Tissues are collections of cells and cell products that perform specific, limited functions

11. Now…
We are moving on to the first Type of Tissue in the body (one of four)

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

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

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

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

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

17. Classes of Epithelia

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

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

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

21. 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)

22. 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)

23. Now… The Connective Tissue
We are moving on to the second type of Tissue in the body (2 of 4)
The Connective Tissue

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

25. 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)

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

27. 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

28. 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

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

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

31. 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

32. 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

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

34. Connective Tissue Types (1 of 4)
Bone (osseous tissue) osteocytes
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

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

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

37. 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

38. Now…
We are moving on to the third type of Tissue in the body
The Muscle Tissue

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

40. 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

41. 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

42. Muscle Tissue Types (3 of 3)
3. Smooth muscle
Surrounds hollow organs
Function: Changes shape to facilitate bodily organ functions
Involuntary muscle
Attached to other smooth muscle cells
No visible striations
One nucleus per cell
Figure 3.20c

43. Do Now What are the three types of muscular tissues?
Which muscle tissues can be controlled voluntarily?
Which are involuntary? Why would you want them to be involuntary?

44. 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

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

46. Tissues Do Now How can tissues become damaged?
How do you think they repair themselves?
Do you think they are all repaired in the same manner?

47. Tissue Repair Wound healing is divided into 4 overlapping states:
Maintaining Homeostasis
Inflammatory Response
Proliferative Phase
Remodeling

48. Maintenance of Homeostasis
Clotting in any damaged regions of the circulatory system
Clears the wound site of debris and prevents infection
Signs: swelling, redness, heat, pain
Inflammatory Response

49. Proliferative Phase Remodeling Stage
New tissue and an extracellular matrix to support tissue repair are laid down
Proliferative Activity of Tissues: Some tissues are continuously dividing, stable until disturbed, or non dividing (regardless of injury)
The rapidly laid down tissue is altered to more closely mimic surrounding, mature tissues
Remodeling Stage

50. If the wound process is interrupted…
Leads to formation of chronic wounds
Or to the development of fibrosis (scar tissue)

51. Determination of method of Tissue Repair
Type of tissue damaged
Severity of the injury

52. Regeneration or Fibrosis?
Regeneration – replaces dead or damaged cells with the SAME type of cell, restoring NORMAL function

53. Regeneration or Fibrosis?
Fibrosis/Scarring – replaces damaged tissue with SCAR tissue (dense fibrous connective tissue), which holds the tissue together, but does NOT restore normal function
Extracellular Matrix components are essential for wound healing
Fibroblasts, macrophages, etc.

54. 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

55. Development of Tissues
After birth, some tissues have cells that have left the cell cycle and are “non-dividing tissues”
Neurons
Skeletal muscle cells
You are born with every muscle fiber you will ever have!
Cardiac muscle cells

56. 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

57. 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

58. #1 Let’s Review Real Quick:
Tissues
Organized into 4 specialized cells:
Epithelial tissue
Connective tissue
Muscular tissue
Nervous tissue

59. #2 Review Division of epithelial tissues into epithelia and glands:
epithelia as avascular barriers for protection
glands as secretory structures

60. #3 Review Classification of epithelial cells:
by number of cell layers (simple or stratified)
by shape of cells (squamous, columnar or cuboidal)

61. #4 Review The functions of connective tissues: structure transport
protection
support
connections
energy storage

62. #5 Review The structure of connective tissues: matrix ground substance
protein fibers

63. #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)

64. #7-8 Review
The 3 types of muscle tissues (skeletal, cardiac, and smooth)
The classification of muscle tissues by striation, nucleation, and voluntary control

65. #9-10 Review
Tissue injuries and repair systems (homeostasis, inflammation, proliferation, remodeling)
The relationship between aging & tissue structure