Epithileum Cheat Sheet
By: Callie Wilkes
Anatomy & Physiology
2350-010
Epithelial Tissues
- Offers the body protections and covers vital organs
- Lines the throat and anus
- Acts like a filter and absorbs nutrients
- Controls excretions (urine and deffication) as well as secretions (sweat)
Epithelial Tissues
Specialized
Features
- Can form sheets; cellularity
- Uniquely strong contact points; junctional complexes
- Contains nerves (innervated) yet doesn't have a blood supply (avascular)
- Can regenerate cells
Classifications of Epithelia
Classification
- Stratified= more than one layer of cells
- Simple= a single layer
- Squamous= flat and thin, basically squished cells
- Cuboidal= square shaped and thicker than squamous cells
- Columnar: rectangular, thin and tall cells
- Psuedostratified: looks like more than one layer with no difinitive shape, more than one of the other shapes are present
Simple Epithilial
Tissue
- Single cell layers and thin
- Simple Squamous Epithelium: found in the kidney and the respiratory tract
- Simple Cuboidal Epithelium: found in glandular tissue and in kidney tubules
- Simple Columnar Epithelium: found in the uterine tube
- Pseudostratified Columnar Epithelium: found in the upper respiratory tract and the urethra
Stratified
Epithelial Tissue
Stratified Epithelial
- Multiple cell layers that regenerate from the basal layer (bottom) to the apical layer (top)
- Keratinized squamous epithileum= hair, nails, hooves, horns, and wool
- Keratinization of cells occurs and the surfacd layers are filled with granuels of keratin
Stratified Cuboidal Epithileum
Stratified Cuboidal & Columnar
- Is generally two layers and found along excretory ducts
- Also found in sweat glands, mammary glands, and salivary glands
- Protects deeper cell layers
Stratified Columnar Epithileum
- Only found in few parts of the respiratory and reproductive systems
- Also found in the digestive system and some of the excretory ducts
Transitional Epithileum
Transitional
- Resembles columnar and cuboidal cells
- Is very stretchy
- Found in the urinart tract and in the urethra