Lecture 3 Flashcards
What holds cells together?
Cell to cell adhesion molecules
Extracellular proteins
Internal-external scaffolding
Close proximity (pressure effect)
Difference between connective and epithelial tissue
Connective lots of extracellular matrix
Connective rarely do cells contact each other
Cells sparsely distributed
Matrix rich in fibrous polymers like collagen
Epithelia have cells bound together in sheets
What is the difference between parenchyma and stormal tissue?
Parenchyma is the functional tissue of an organ
Stromal tissue is the structural tissue of organs, generally connective
What is the primary cell of connective tissue?
Mesenchymal stem cell (mesoderm) and becomes a fibroblast
What is connective tissue made of?
Cells- primarily fibroblasts
Fibres- collagen, elastin, reticular
Ground substance- glucosaminoglycans such as hyaluronic acid
Function of fibroblasts?
Make extracellular matrix and collagen
Connective tissue functions?
Binding and support Protecting Insulating Separating tissue and organs Storing fuel and cells Transport of substances
What is paracellular transport?
When substances move between cells through tight junctions in the case of epithelium
What is the role of tight junctions?
To prevent larger molecules from moving through the epithelium and into deeper tissue layers.
What are endothelial cells?
Specialised epithelial cells that line blood vessels.
What are adhesion junctions?
Make a belt all the way through epithelial layer to keep cells together and also act as a barrier.
What is the strongest cell to cell adhesion?
Desmosomes- only adhesion found in epidermal cells
What is the role of gap junctions?
Important role in muscle contraction as allow the movement of calcium between cells in cardiac and smooth muscle.
Where are hemI-desmosomes found?
At the basal surface of epithelial cells. Anchor cell to basal lamina and prevent loss of epithelial cells.
What do all epithelial cell adhesion methods require to work?
Calcium