Session 6 - Epithelia Flashcards
Where is simple squamous epithelium located?
Lining the blood and lymph vessels (endothelium) and lining the body cavities including the pericardium, pleura and peritoneum (mesothelioma)
What is epithelia?
Sheets of cells that over external surfaces of the body and line the internal surfaces.
What is simple epithelia?
One cell thick layer attached to the basement membrane.
What is the basement membrane?
Thin, flexible layer between the epithelial cells and the connective tissue.
What is stratified epithelia?
More than one cell thick layer attached to the basement membrane.
What are the 4 layers of the Epidermis?
Horny Layer (stratum cornermen), granular layer, prickle cell layer and the basal layer.
What are keratinocytes and where are they found?
Synthesise keratin which gives the cells strength. They are produced in the basal layer but migrate up through the prickle layer.
What type of epithelia is the epidermis made up of?
Stratified squamous
What types of cells are in the epidermis?
Keratinocytes, melanocytes and langerhan cells
What are melanocytes and where are they found?
They are dendritic cells that produce melanin. They are found in the basal layer of the epidermis
What are Langerhan cells and where are they found?
They are dendritic cells which present antigens to T Lymphocytes and mediate immune reactions. They are found in the prickle layer of the epidermis.
What are the functions of the epidermis
Protect from abrasion, trauma and water loss. Shield from UV damage.
What is transitional epithelium?
Epithelium which can stretch to give a cuboidal shape and relax to have a columnar shape.
Where are transitional epithelia located?
Urethra, bladder and ureter
What is Pseudostratified epithelia?
Where all the cells are attached to the basement membrane despite it looking as if there are several layers of cells. Therefore, some cells reach the lumen but others don’t.
