Week 2 - Cells, Tissues, Organs Flashcards
What is Tissue
A group of cells that shares a common structure and features and are arranged in a patter
What are the types of tissue (4)
- Epithelial Tissue
- Connective Tissue
- Nervous Tissue (excitable tissue)
- Muscle Tissue (excitable tissue)
What is Epithelial tissue
sheets of cells which cover the exterior surfaces of the body, lines internal cavities and passageways and forms certain glands
What are the cell junctions (3) - in Epithelial tissue
- Tight Junction
- Gap Junction
- Anchoring Junction
Tight junction
Anchoring Junction
Gap Junction
What is a tight junction
- Prevents molecules from passing between cells
- Forms continuous seal around the cell
- stops viral infections
What are anchoring junctions (desmosomes)
- Acts like velcro
- Holds tissue together but doesn’t prevent the movement of molecules between them
- More flexible than tight
- Found in skin and heart since they have to move but have to hold together
What are gap junctions
- a intercellular passageway between cells which allows the movement of small molecules and ions
Simple Squamous
Stratified Squamous
Simple Cuboidal
Stratified Cuboidal
Simple Columnar
Stratified Columnar epithelium
Pseudostratified Columnar
Function of simple squamous
- Commonly involved in diffusion, osmosis, filtration, absorption or transport of materials
- allows for fast gas exchange (less distance for diffusion)
Example of simple squamous
alveoli of lungs
Function of stratified squamous epithelium
Protects against abrasion
- can secrete mucus to lubricate
- easily replaced