1. Chapter 3 Body Tissues
He he he he he…

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

3. Epithelial Tissues Locations Functions Characteristics Body coverings
Body linings
Glandular tissue
Functions
Protection
Absorption
Filtration
Secretion
Characteristics
Cells close together
Cells have free apical surface
Bottom surface is basement membrane
Avascular – no blood supply
Regenerate easily

4. Classification of Epithelium
1. Based on # of cell layers
Simple – one layer
Stratified – more than one layer
2. Shape of cells
Squamous – flattened
Cuboidal – cube-shaped
Columnar – column-like

5. Simple Epithelium 1. Simple squamous Single layer of flat cells
Usually forms membranes
Lines body cavities
Lines lungs and capillaries

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

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

8. 4. 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

9. Stratified Epithelium
1. Stratified squamous
Cells at the free edge are flattened
Found as a protective covering where friction is common
Locations
Skin
Mouth
Esophagus

10. Rare in human body 2. Stratified cuboidal 3. Stratified columnar
Two layers of cuboidal cells
3. Stratified columnar
Surface cells are columnar, cells underneath vary in size and shape
Both are:
Found mainly in ducts of large glands

11. Glands Gland – one or more cells that secretes a particular product
2 types
1. Endocrine gland
Ductless
Secretes hormones
2. Exocrine gland
Empty through ducts to surface
Include sweat and oil glands

12. 4. Transitional epithelium
Shape of cells depends upon the amount of stretching
Lines organs of the urinary system

13. Connective Tissue Most abundant and widely distributed
Some have good blood supply (vascularized)
Some don’t (avascular)
All have extracellular matrix – nonliving material surrounding cells
Functions
Binds tissues together
Supports
Protects

14. Extracellular Matrix Two parts
Ground substance – mostly water along with adhesion proteins and polysaccharide molecules
Fibers
Produced by the cells
3 types
Collagen fibers
Elastic fibers
Reticular fibers

15. Connective Tissue Types
1. Bone (osseous tissue)
Bone cells in lacunae (cavities)
Hard matrix of calcium salts
A lot of collagen fibers
Protect & supports body

16. Connective Tissue Types
2. Hyaline cartilage
Most common cartilage
Lots of collagen fibers
Rubbery matrix
Fetal skeleton & ribs

17. Connective Tissue Types
3. Elastic cartilage
Provides elasticity
found in external ear,
epiglottis, & trachea

18. Connective Tissue Types
4. Fibrocartilage
Highly compressible
forms cushion-like discs between vertebrae

19. Connective Tissue Types
5. Dense
Main matrix element is collagen fibers
Cells are fibroblasts
Tendon –
muscle to bone
Ligaments –
bone to bone

20. Connective Tissue Types
6. Areolar
Most widely distributed
Soft, pliable tissue
Contains all fiber types
Can soak up excess fluid
Think “airy”

21. Connective Tissue Types
7. Adipose
Similar to areolar with fat globules
Many cells contain large lipid deposits
Functions
Insulates body
Protects organs
Fuel storage

22. Connective Tissue Types
8. Reticular
Delicate network of fibers
Forms network of lymphoid organs
Lymph nodes
Spleen
Bone marrow

23. Connective Tissue Types
9. Blood
cells & fluid matrix
Fibers visible during clotting
Transports materials

24. Muscle Tissue Function = produce movement 3 types Skeletal muscle
move muscles of skeleton
Cardiac muscle
only found in heart
Smooth muscle
found in organs & vessels

25. Muscle Type
Type of Control?
Striations?
How many nuclei?
Skeletal
Voluntary
Yes
Many per cell
Cardiac
Involuntary
Yes & intercalated disks
1 per cell
Smooth No

26. Nervous Tissue Neurons and nerve support cells
Function = send impulses to other areas of the body
Irritability – able to respond to stimuli
Conductivity – conducts messages