1. Do Now
What is the definition of a tissue? Think about what makes up a tissue.
Take a look at your brachial. What kind of tissues do you think make up your brachial?

2. Histology- Study of Tissues
Chapter 5
Pages:

3. How does someone create a Beating heart?!

4. Do Now
Look back at the list you made of the types of tissues that make up the brachial.
What do you think are the functions of those tissues?

5. Objectives
Explain the difference between the different kinds of tissues
To Identify the types of Epithelial Tissues
To list the locations of each type of epithelial tissue

6. Have an issue? Need some tissues?
Tissues: Groups of specialized cells which are similar in structure and perform common functions.
4 Types of Tissues
Epithelial
Form protective coverings
Function in secretion and absorption
Connective
Provide support and protection
Bind structures together
Nervous
Control and coordinate body activities
Muscle
Produce body movements
* Most organs contain all 4 types

7. Epithelial Tissue: Where is it located?
Forms covering of body surfaces
Covers organs
Forms inner lining of body cavities
Lines hollow organs
Major tissue in glands

8. Epithelial Tissue: Functions
Protection from physical/chemical injury, infection, and dehydration
Secretion, excretion, filtration and reabsorption of materials
Ex: mucous glands and sweat glands
Diffusion of certain gases, ions, and nutrients
Sensory reception
Has Sensory Neurons

9. Epithelial Tissue: Special Characteristics
One free surface always exposed to the outside or open internal space: apical surface
Attached to basement membrane on the other side
Cells are tightly packed together
Avascular: NO blood vessels!! Rely on diffusion from underlying connective tissue
Divides rapidly by mitosis to replace damaged cells
Classified according to top layer of cells

10. How to Classify Epithelial Tissue
1. Layers:
Simple: just one layer
Absorption
Secretion
Filtration
Stratified: 2 or more layers
Protection

12. How to Classify Epithelial Tissue Continued
2. Shape:
Squamous: thin and flat
Disc shaped nucleus (scale-like)
Columnar: columns
Oval nucleus
Cuboidal: cubed (square shaped)
Center round nucleus

13. Squamous Epithelium 1. Simple Squamous
Single layer that is delicate (can be easily damaged)
Functions:
Diffusion
Absorption
Filtration
Secretion
Locations:
Alveoli of the lungs
Capillary walls
Lines blood and lymph vessels

14. Squamous Epithelium 2. Stratified Squamous
Multiple layers of cells (helps make tissue thicker)
Functions:
Protection against abrasion
Protection against Pathogens
Protection against chemicals
Two Types:
A. Keratinized:
Layers of dry, dead squamous cells
Cells produce a protein called keratin through a process called keratinization to harden and then die.
Prevents water/substance loss
Helps block chemicals and other organisms from entering
Location:
Epidermis
B. Non-Keratinized:
Cells kept moisten
Locations:
Oral Cavity
Esophagus
Vagina
Anal Canal

15. Cuboidal Epithelium 2. Stratified Cuboidal Simple Cuboidal
About 2-3 layers of cube-shaped cells
Rare
Function:
Secretion
Absorption
Larger ducts of glands
Location:
Mammary glands
Sweat glands
Salivary Glands
Pancreas
Simple Cuboidal
Single layer of cube-shaped cells
Functions:
Secretion
Absorption
Locattion:
Ovaries
Kidney tubules
Ducts of glands (salivary, thyroid, pancreas and liver)

16. Columnar Epithelium 2. Stratified Columnar 1. Simple Columnar
Multiple layers of tall, thin cells resting on layers of cuboidal cells
Rare
Functions:
Secretion
Absorption
Locations:
Small portion of male urethra
Parts of the pharynx
1. Simple Columnar
Single layer of tall, narrow cells
Nuclei are near the basement membrane
Can contain Cilia
Goblet cells are often present
These secrete mucus to protect tissues
Functions:
Absorption
Secretion
Locations:
Uterus
Stomach
Intestines
Most organs of digestive tract

17. Columnar Epithelium 3. Pseudostratified Ciliated Columnar
Appeared stratified but are only a single Layer of cells
Nuclei appear scattered to give this effect
All cells touch basement membrane and have cilia on apical surface
Goblet cells are also present
Functions:
Move material across the surface
Locations:
Nasal cavity
Passageway of respiratory system

18. Transitional Epithelium
Changes in response to tension
Relaxed: Looks like stratified cuboidal
Stretched: Looks like squamous
Function:
Tolerates excessive stretching
Location:
Bladder
Ureters
Urethra