1.6 Epithelium I Flashcards
What are the 4 types of tissues?
Epithelium
Connective Tissue
Muscle Tissue
Nerve Tissue
Define Epithelium
- Lines everything in the body (covers and lines membranes)
- Forms glands
- Tight cells
- Small amount in extracellular matrix
Define Connective Tissue
- A “filler”
- Protection and support
- Stores energy
- Provides immunity
- ALWAYS associated with a lot of extracellular matrix
- Loose cells
Define Muscle Tissue
- Enables contraction
- Elongated cells
- Moderate amount in ECM
Define Nerve Tissue
- Initiates and transmits action potentials (nerve impulses)
- Long and numerous cell shape
- Minimal amount in ECM
Is the epithelium vascular or avascular? Why?
Avascular b/c there’s a rich blood supply under it
Where is bilayered epithelium located?
In the ducts of body
Where is multilayered epithelium located?
Where highly abrasive surfaces are
- Ex: epidermis
Is there single layered epithelium?
Yes
What’s the role of the basement membrane?
It attaches the epithelium to underlying tissues (usually connective tissues)
What does the epithelial cell polarity help with?
Helps with its function of transporting and secreting
Epithelial cells typically line what type of surface?
Free surface
What are the primary germ layers of the epithelial cells and what are their subsections?
Ectoderm
- Epidermis
- Nervous System
Endoderm
- Lining of respiratory and GI tracts
- Glands
Mesoderm
- Connective tissue
- Muscle
- Cardiovascular system
Define ectomesenchyme-neural crest
A group of cells that migrate from ectoderm to mesoderm
What are the functions of epithelial cells?
Protection Absorption Secretory (sweat glands) Transport Excretory (gets rid of waste) Sensory Contractile
What are the epithelial cell subdivisions?
Surface epithelium (covers and lines membranes) Glandular epithelium (exocrine and endocrine glands; secretion and absorption)
What helps determine surface epithelium’s function?
Number of layers
Morphology of surface cells
Surface specializations and modifications
What are the types of surface epithelium and what are the types within those?
Simple epithelia
- Simple squamous
- Simple cuboidal
- Simple columnar
Pseudostratified epithelia
- Pseudostratified columnar
- Pseudostratified ciliated columnar
Stratified epithelia
- Stratified squamous (keratinized and non-keratinized)
- Stratified columnar
- Transitional
What are the types of simple squamous epithelium?
Endothelium
- Name given to all blood vessels
- Ex: arteries
Mesothelium
- Outside lining in big cavities
- Ex: lungs
What type of epithelium is this?
Simple squamous
What type of simple squamous epithelium is this?
Endothelium
What type of simple epithelium is this?
Mesothelium
What type of epithelium is this?
Simple cuboidal
What type of epithelium is this?
Simple columnar
