Cells and tissues- overview Flashcards
What is the matrix?
This is produced by connective tissue cells and secreted to exterior. It consists of ground substance and fibres.
What is ground substance?
This is comprised of mostly water and cell adhesion proteins (act as glue to allow connective tissue cells to attach to matrix fibres)
What kind of fibres are in the matrix?
Collagen, reticular
What is dense connective tissue?
This is where collagen fibres are main matrix element and have rows of fibroblasts (seen in tendons and ligaments)
What is loose connective tissue?
These are softer, have more cells and fewer fibres (types are areolear, adipose, reticular).
What is areolar connective tissue?
Most widely distributed, soft and cobwebby that protects the organs it wraps. It hold the internal organs together and in position. Matrix appears to be empty space, involved in oedema.
What is adipose connective tissue?
This is commonly called fat, droplet of oil occupies most of the volume, insulates body and protects from bumps and extreme temp. Protects organs individually (kidneys surrounded by capsule of fat).
What is reticular connective tissue?
Delicate network of woven reticular fibres (resemble fibroblasts), forms stroma. In spleen, lymphatic nodes.
What are the three types of cell membrane junctions?
-Tight junctions
-Desmosomes
-Gap junctions
What are tight junctions?
Impermeable junctions, bind cells together into leakproof sheets. Plasma membranes fuse together to stop substances from passing through.
What are desmosomes?
These are anchoring junctions scattered like rivets along sides of adjacent cells. Prevent cells from stress (heart and muscle cells) from being pulled apart.
What are gap junctions?
These function to mainly allow communication. commonly in heart and between embryonic cells.
What are connexons?
Proteins that span width of membranes.
