Epithelial cells Flashcards
What are haemopoietic cells?
Blood cells, tissue-resident immune cells, and cells derived from bone marrow.
What are neural cells?
Cells that constitute the nervous system: Neurones (transmit electrical signals), and glial cells (provides neurone support and insulation - Schwann cell).
What are contractile tissues?
Skeletal muscle, cardiac muscle, smooth muscle.- Tissue with the ability to contract.
What are connective tissue cells?
Fibroblasts (many tissues), chondrocytes (cartilage), osteocytes (bones)- Connects, bind and supports tissue cells.
What are epithelial cells?
Cells forming continuous layers, layers line surfaces and separate tissues compartments- variety of alternative function- Secretion, selective absorption, protection, transcellular transport and sensing.
What are squamous epithelial cells?
Flattened, plate shape, abundant cytoplasm and small round circular nucleus.
What are columnar cells?
Arranged in columns; approximately 3000 microvilli per cell (maximises surface area for absorption). Simple columnar epithelial cells secrete molecules- enterocytes assist in molecular degradation in gut.
What are cuboidal cells?
Cuboidal: Cube-like (lines nephrons, ovaries and ducts)- main function is secretion.
What are stratified epithelium?
Multiple layers of cells
What are pseudo-stratified epithelium?
This epithelium appears to be multi-layered, but on close examination, the surface cells havecontactwith the basal lamina. e.g. airway (trachea and bronchi) epithelium, various ducts in the urinary and reproductive tracts.
What is epithelial cell polarity?
Membrane is organised into discrete domains through formation of junctions, distinct polarity has apical membrane at the luminal surface and a basolateral domain (basal surface is in contact with the extracellular matrix)
What is a lateral membrane?
Membrane is situated between two surfaces, membranes of adjacent membrane appose each other
Why is polarity important?
Important for secretion of fluid, and solute transport
Directional flow and ion/cotransporter proteins
What are tight junctions?
Belt around apical lateral membrane (membranes of two adjacent cells accumulate together to form a barrier). Membranes are attached by strands of transmembrane proteins (claudins and occludins). Binding action prevents molecules from passing in between the cells- helps to main cell
What are adherens?
Initiation and stabilisation of cell-cell adhesion, regulation of the actin cytoskeleton, intracellular signalling, and transcriptional regulation. Junction holds adjacent epithelial cells together.
