1. DR / Noha Elsayed 2015--2016 Body Tissues

2. Course outline

3. Learning outcome By the end of this lesson the student will be able to: 1.Describe the general characteristics and functions of epithelial tissue. 2. Name the major types of epithelial tissue, and relate each one to a particular organ. 3.Describe the general characteristics and functions of connective tissue. 4.Name the major types of connective tissue, and relate each one to a particular organ.

4. 5.Describe the general characteristics and functions of muscular tissue. 6.Name the major types of muscular tissue, and relate each one to a particular organ. 7.Describe the general characteristics and functions of nervous tissue. Learning outcome cont’d

5. Cells are specialized for particular functions. Tissues  Groups of cells with similar structure and function Four primary types  Epithelium  Connective tissue  Nervous tissue  Muscle Body Tissues

6. Epithelial Tissues  Found in different areas :-  Body coverings  Body linings  Glandular tissue  Functions :-  Protection  Absorption  Filtration  Secretion

7. Cells fit closely together Tissue layer always has one free surface The lower surface is bound by a basement membrane Avascular (have no blood supply)

8. Number of cell layers  Simple – one layer  Stratified – more than one layer

9. Shape of cells :- Squamous – flattened Cuboidal – cube-shaped Columnar – column-like

10. Simple squamous  Single layer of flat cells  Usually forms membranes  Lines body cavities  Lines lungs and capillaries

11. Simple cuboidal  Single layer of cube-like cells  Common in glands and their ducts  Forms walls of kidney tubules  Covers the ovaries

12. Simple columnar  Single layer of tall cells  Often includes goblet cells, which produce mucus  Lines digestive tract

13. Pseudostratified  Single layer, but some cells are shorter than others  Often looks like a double cell layer  Sometimes ciliated, such as in the respiratory tract  May function in absorption or secretion

14. Found everywhere in the body Includes the most abundant and widely distributed tissues Functions :-  Binds body tissues together  Supports the body  Provides protection

15. Connective Tissue Characteristics Variations in blood supply :- Some tissue types are well vascularized Some have poor blood supply or are avascular Extracellular matrix :- Non-living material that surrounds living cells

16. Two main elements :- Ground substance – mostly water along with adhesion proteins and polysaccharide molecules Fibers :- Produced by the cells Three types  Collagen fibers  Elastic fibers  Reticular fibers

17. Bone (osseous tissue) Composed of:  Bone cells in lacunae (cavities)  Hard matrix of calcium salts  Large numbers of collagen fibers  Used to protect and support the body

18. Hyaline cartilage :- Most common cartilage Composed of:  Abundant collagen fibers  Rubbery matrix  Entire fetal skeleton is hyaline cartilage Fluid connective tissues:- (blood, lymph)

19. Specialized for the conduction of electrical impulses. Two basic types of cells: – Neurons: basic structure of neural tissue – Neuroglial cells: divide and support nervous tissue components

20. Function is to produce movement Three types :-  Skeletal muscle  Cardiac muscle  Smooth muscle

21. Skeletal muscle  Can be controlled voluntarily  Cells are striated  Cells have more than one nucleus

22. Cardiac muscle :-  Found only in the heart  Function is to pump blood (involuntary)  Cells attached to other cardiac muscle cells at intercalated disks  Cells are striated  One nucleus per cell

23. Smooth muscle  Involuntary muscle.  Surrounds hollow organs.  No visible striations.  One nucleus per cell.

24. Neurons and nerve support cells Function is to send impulses to other areas of the body :-  Irritability  Conductivity

25. Regeneration Replacement of destroyed tissue by the same kind of cells Fibrosis Repair by dense fibrous connective tissue (scar tissue)

26. 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 Cardiac muscle Nervous tissue within the brain and spinal cord

30.  Body tissues are categorized into four types: epithelial, connective, muscular, and nervous.  Epithelial is classified according to cell shape and number of layers. The cell shape can be squamous, cuboidal, or columnar.  Simple tissues have one layer of cells, and stratified tissues have several layers.

31. Connective Tissue  In connective tissue, cells are separated by a matrix (organic ground substance plus fibers).  A. Fibrous connective tissue can be loose connective tissue, in which fibroblasts are separated by a jellylike ground substance, or dense connective tissue, which contains bundles of collagenous fibers.  B.Adipose tissue is a type of loose connective tissue in which the fibroblasts enlarge and store fat.

32. Muscular Tissue :-  Muscular tissue contains actin and myosin protein filaments. These form a striated pattern in skeletal and cardiac muscle, but not in smooth muscle. Cardiac and smooth muscle are under involuntary control.  Skeletal muscle is generally under voluntary control.

33. Nervous Tissue :-  Nervous tissue contains conducting cells called neurons. Neurons have processes called axons and dendrites.  In the brain and spinal cord, axons are organized into tracts. Outside the brain and spinal cord, axons (fibers) are found in nerves.