Epithelia Flashcards
What does epithelia comprise of
It comprises of cohesive sheets of cells, with one or more layers resting on a basement membrane
What do epithelia form barriers for
Protection
Absorption
Secretion
What is simple epithelia
Single layer of cells on a basement membrane
What is stratified epithelia
Tow or more layers of cells on the basement membrane
What are characteristics of simple squamous epithelium
Single layer of flattened plate like cells on the basement membrane
Parallel oval nuclei
Where can simple squamous epithelium be found
Lines blood vessels
Outside of the lungs
Abdominal organs
What are characteristics of simple cuboidal epithelium
Single layer of cells with a similar height and width that sit on a basement membrane
Central spherical nuclei
Where can simple cuboidal epithelium be found
Lining the kidney tubules and small ducts
What are characteristics of simple columnar epithelium
Single layer of cells taller than they are wide that sit on a basement membrane
May or may not have microvilli
Where is simple columnar epithelium be found
Lines the stomach, intestines and uterus
What are microvilli
Microscopic projections on a luminal surface of absorptive cells
What are the advantages of a tissues having microvilli
Increases surface area
Where can you find an example of cells having microvilli
Intestinal cells making up the intestinal brush border
What are cilia
Microscopic motile projections on luminal surfaces of cells
Where can cilia be found
Respiratory tract and reproductive tract
What are features of stratified epithelia
Protective feature
Many layers of cells
Cells are continuously been worn down and replaced by the cells from below
Where can stratified epithelia be found
Sites that are subject to abrasive forces
What is stratified squamous non-keratinising epithelium
Multiple layer of cells on a basement membrane
Mature surface layers which are plate-like squames
Where is stratified squamous non-keratinising epithelium found
Lines the mouth, oropharynx, oesophagus and vagina
What are characteristics of stratified squamous keratinising epithelium
Multiple layers of cells on a basement membrane
Mature surface layers are plate-like squames
Waterproof layer of keratin
What is an example of stratified squamous keratinising epithelium
Skin
What are characteristics of pseudostratified epithelium
Single layer of cells of variable height, which mimicking multiple layers on a basement membrane
All cells in contact with basement membrane
Where is pseudo-stratified epithelium located
Lines the conducting airways
What is an example of a specialised stratified epithelium
Urothelium
What is a basement membrane and its function
Always present in tissue cells
It function is to show the difference between epithelium and underlying connective tissue and essential for the proper functioning and survival of the epithelium
What is a basement membrane made up of
It is composed of several extra-cellular proteins including collagen IV and fibronectin
The basement membrane usually can’t be seen, what is the exception for this
The basement membrane can be seen when stained with PAS
What are tight junctions and where are they found
Tight junctions are found in the epithelium and are band-like fusions between cells which prevent diffusions
What are desmosomes
They are a type of epithelial junction also known as anchoring/adherent junctions
They form plaques which form physical joins between cells and connect the cytoskeletons of adjacent cells which spread forces across several cells
What are communicating junctions
They are a type of epithelial junction also known as gap junctions which are electrical junctions that permit the transfer of small molecules
They electrically couple adjacent cells
What is this tissue
Simple epithelia
What is this tissue
Stratified epithelia
What tissue is this and where is the image taken from
Simple squamous epitelium
The image is of lung alveoli tissue
What tissue is this and where is the image taken from
Simple squamous epithelium
The image is of peritoneum tissue
What tissue is this and where is the image showing
Simple cuboidal epitelium
The image is of kidney tissue
What tissue is this and where is the image taken from
Simple cuboidal epithelium
The image is of a salivary gland
What tissue is this and where is the image of
Simple columnar epithelium
The image is of the stomach tissue
What tissue is this and where is the image taken of
Simple columnar epithelium
The image is of small intestine tissue
What tissue is this and where is the image of
Stratified squamous non-keratinising epitelium
The image is of oesophagus tissue
What tissue is this and where is the image of
Stratified squamous non-keratinising epithelium
The image is of vaginal tissue
What tissue is this and where is this image of
Stratified squamous keratinising epithelium
This image is of thin skin
What tissue is this and where is the image from
Stratified squamous keratinising epithelium
This image is of thick skin
What tissue is this and where is the image of
Pseudostratified epithelium
The image is of the trachea
What tissue is this where is this image of
Urothelium
Specialised stratified epithelium
This image is showing bladder tissue
What is the black line representing
Basement membrane
What is this showing
Tight junctions a type of epithelial junctions
What is this showing
This is showing desmosomes a type of epithelial junctions
What is this showing
They are gap or communicating junctions which are a type of epithelial junctions
