Epithelial tissue

Epithelial cells

Simple Squamous Epithelium

Stratified Sqaumous Epithelium

Simple Cuboidal Epithelium

Stratified Cuboidal Epithelium

Simple Columnar Epithelium

Pseudostratified Columnar Eptihelium

Locations Cardiovascular System and Lymphatic vessels, visceral & parietal pleura, visceral & parietal pericardium, visceral & parietal peritoneum.

Function Diffusion, Filtration, Secreting Lubricating substances

Microscope Single layered "egg like" cell

Microscope Cilliated and false apperance of multiple layered cells

Locations Upper trachea and upper respiratory tract

Functions Secretes mucus and ciliated tissue moves the mucus

Microscope Single layered ciliated column shaped cells

Location lines bronchi, uterine and uterus, bladder, digestive tract

Functions Absorbs; Secretes mucous and enzymes

Microscope Multiple layered "cube like cells

Location sweat glands, salivary glands and mammary glands

Function Protective tissue

Location in ducts and secretory portions of small glands and in kidney tubules

Stratified Columnar epithelium

Location male urethra and some ducts in glands

Microscope Multiple layered "column shaped" cells

Function Secrets and protects

Function Secrets and absorbs

microscope Single layered "Cube like" cell

Microscope Multiple layered "egg like" cell

Location Lines Mouth, esophagus, and vagina

Function Protects against abrasion

Overview of functions

Covers the body surface and body cavities

Protection

Secretions

Exocrine

protects underlying tissue from Abrasions and foreign bodies

Absorption

Bringing small Molecules into the cell

Diffusion

Movement of molecules against their concentration gradient

Endocrine

Glands made cells that secrete substances on the epithelial surface

Glands that secrete substances into the blood stream

Filtration

Small molecules will be sieved through cell membrane

Sensory

Avascular

Innervated

No viens or arteries present

nerve cells present at the epithelial layer

Special Characteristics

Goblet cell

Microvilli increase surface area and sweep mucus

Golgi apparatus incases mucin in secretory vesicles

looks like a lighter epithelial cell in microscope

Epithelial cell

Apical region

basal region

Cell junction

tight junction holds cells together

gap junction allows ions and small molecules to pass through cells

Desomosome(link the cells like doors to rooms)

basal region sits on basement membrane

The apical region is superficial to the rest of the cell; it is polar; has direct contact with lumen(body cavity)

Transitional epithelium

Look like stratified cuboidal

found in urinary bladder and ureters

Lecture notes

Cilia sweep and microvilli don't sweep (they increase surface area to help with absorbtion

Apical layer of cells will be lighter in color in microscope do to more proteins present at basal layer due to more proteins present

the fact that epithelial cells are so close to one another is defined as cellularity

Histology is the study of tissue; histology is done with a microscope

All epithelial tissue are supported by connective tissue

Regeration

certain epithelial cells are destroyed frequently so they must be able to regenerate.