1. bellwork

2. Chapter 4: Tissues
4.1: Epithelial Tissue

3. Tissues Tissues are made up of cells
Cells connect with one another via different junctions to form tissues
Tight Junctions: cells join together VERY tightly
Example: cells in the intestine
Gap junctions: spaces or “gaps” between cells that allow the flow of molecules
Example: calcium between cells
Adhesion junctions: act like “staples” to hold the cells together in the tissue
Example: skin cells

5. Tissues There are 4 primary Tissue Types
Epithelium: covers the body surfaces, lines body cavities, and forms glands
Connective: protects and supports the body
Muscular: generates physical force needed for body movements
Nervous: detects changes inside and outside the body, coordinates body activities

6. Epithelial tissue Divided into 2 types Functions
Covering & Lining Epithelium:
Covers the surface outside of the body and lines internal organs
Glandular Epithlium:
Makes up the secreting portion of glands (sweat glands)
Secretes hormones or other products
Functions
Protection, Absorption, Filtration and Secretion

7. Epithelial tissue Characteristics
Epithelial cells are packed closely together to form continuous sheets
Epithelial cells have an apical surface and a basal surface
Apical: most superficial layer of cells
Basal: deepest layer of cells; between the epithelium and the underlying connective tissue
Epithelial cells are avascular — they lack blood vessels
Can regenerate easily – cells are replaced quickly

8. Epithelial tissue Covering and Lining Epithelium
Classified according to the number of layers and the shape of the cells
Number of layers
Simple: one layer
Stratified: more than one layer
Pseudostratified: looks like many layers but it’s only one layer

9. Epithelial tissue Covering and Lining Epithelium
Shape of cells
Squamous: flattened
Cuboidal: cube - shaped
Columnar: column-like
Combining number of layers and cell shape creates the different types of covering and lining epithelium

10. Check For understanding 1
What are tissues made off
Cube-liked shaped cells
Type of tissue which supports and protects the body
Junctions which hold cells very close together
Tissue which detects chages inside and outside the body
Looks like multiple layers but is only one layer of cells
The 4 characteristics of epithelial tissue

11. Epithelial tissue Simple Epithelium Simple Squamous
Single layer of flat cells
Found in the air sacs of lungs and lining of the heart and blood vessels
Allow materials to pass through by diffusion and filtration
Secretes lubricating substances

12. Epithelial tissue Simple Epithelium Simple Cuboidal
Single layer of flat cube-shaped cells
Found in the ducts and secretory portions of small glands and in kidney tubules
Secretes and absorbs

13. Epithelial tissue Simple Epithelium Simple Columnar
Single layer of tall/column like cells
Ciliated Tissues: found in bronchi, uterine tubes and uterus
Smooth(unciliated): found in the digestive tract, bladder
Absorbs and secretes mucous and enzymes

14. Epithelial tissue Simple Epithelium Pseudostratified
Single layer of cells, some are shorter than others
Often looks like a double layer
Lines the trachea and the upper respiratory tract
Secretes mucus, and moves mucus

15. Epithelial tissue Stratified Epithelium Stratified squamous
Multiple layers of flat squamous cells
Lines the esophagus, mouth and vagina
Protects against abrasion

16. Epithelial tissue Stratified Epithelium Stratified cuboidal
Rare
Function is mainly protection, secretion and absorption
Stratified columnar
Function is protection and secretion

17. Epithelial tissue Stratified Epithelium Transitional epithelium
Shape of cells depends upon the amount of stretching
Lines the bladder, urethra, and the ureters
Allows the urinary organs to stretch and expand

18. Epithelial tissue Glandular Epithelium
Function is to secrete enzymes, hormones, oil, sweat, earwax, saliva and mucus
Two major glandular epithelium gland types
Endocrine gland: secretes hormones directly into the bloodstream
Example: thyroid gland secretes the hormone thyroxin into the bloodstream and is distributed throughout the body raising metabolism
Exocrine gland: secretes their substances into tubes which carry the secretions to the epithelial surface
Example: sweat glands, saliva, mammary glands

19. Epithelial tissue

20. Epithelial tissue Video
You’ll watch a review video and answer the questions you’ll find at the end of your notetaker
These will be for a grade, if you don’t answer the questions because the video is to fast just pay attention, you’ll have time after the video to answer the questions