Cell Junctions Flashcards
(16 cards)
What are the two main criteria for classifying epithelial tissues?
Cell arrangement and cell shape
Epithelial tissues can be categorized based on the arrangement of cells and their shapes.
What is a simple epithelial tissue?
A single layer of cells involved in secretion, absorption, and filtration
Simple epithelia are essential for various physiological functions.
What is a stratified epithelial tissue?
Multiple layers of cells primarily functioning for protection
Stratified tissues are crucial for protecting underlying tissues.
What characterizes pseudostratified epithelial tissue?
A single layer of cells with nuclei at different levels
It functions in secretion and appears layered.
Define squamous epithelial cells.
Flat cells ideal for diffusion and filtration
Squamous cells facilitate processes like gas exchange.
What are cuboidal epithelial cells?
Cube-shaped cells involved in secretion and absorption
Commonly found in glands and kidney tubules.
Describe columnar epithelial cells.
Tall, column-shaped cells that are metabolically active, involved in secretion and absorption
They often have microvilli or cilia.
What are transitional epithelial cells?
Stratified epithelium that can change shape, found in the urinary system
This allows for flexibility in response to volume changes.
What is simple squamous epithelium?
Thinnest layer, functions in diffusion, filtration, and secretion
Found in linings like mesothelium and endothelium.
Where is simple cuboidal epithelium found?
In pancreatic ducts and kidney tubules
It is involved in secretion and absorption.
What is the function of simple columnar epithelium?
Involved in absorption and secretion, may have microvilli or cilia
Commonly found in the small intestines and gallbladder.
What characterizes stratified squamous epithelium?
Apical layer is squamous; basal layers can be cuboidal or columnar
Can be keratinized (skin) or non-keratinized (moist areas).
Where are stratified cuboidal and columnar epithelia typically found?
In the urethra and glandular ducts
These types are rare and mainly involved in secretion and absorption.
What is pseudostratified epithelium commonly associated with?
Ciliated with goblet cells for secretion and movement
Found in the upper airway.
What are covering and lining epithelia?
Epithelia that cover outer surfaces and line inner surfaces
Includes skin and linings of cavities, ducts, and vessels.
What are glandular epithelia?
Composed of secretory cells, includes endocrine and exocrine glands
Endocrine glands secrete hormones into the blood; exocrine glands secrete substances into ducts.
