Lecture 10: connective tissue Flashcards
Define what connective tissue is by defining its structure.
Made ground substance, fibre and cells
Give 3 functions of connective tissue.
- hold & support organs, skin
- shock absorber
- heat insulation
- protect the vital organs
- separate tissues
- transporting substances
- fuel + storage
Name some examples of the main connective tissue cells.
- chondrocytes
- osteoblasts/cytes/clasts
- fibroblasts
- stem cells/progenitor cells/BM/blood/adipocytes
- reticulocytes
- macrophages
- mast cells
What are the main products of connective tissue?
- fibres
- wax or gel-like substances
- GS
Name some examples of fibres you can find in connective tissue.
- elastin
- collagen 1-4
- reticulin
Name what ground substance (GS) is made out of and identify an example.
Proteoglycans: hyaluronic acid
Describe what these suffixes mean…
- blast
- cyte
- clast
Blast: create, grow, make…
Cyte: maintain, finished state…
Clast: destroy, break down…
Extracellular matrix is made of 2 (3) substances. What are they?
GS + fibre (+cells)
How can connective tissue be classified?
Loose/areolar connective tissue
Dense/fibrous/collagenous connective tissue: irregular or regular
Describe the structure of loose connective tissue.
Contains many types of cells: fibroblast, macrophages, adipocytes, mast cells, WBCs
Contains fibres: elastin & collagen
Blood vessels, cells, fibres lie in gel-like GS
What are some functions of connective tissue?
Holds vessels that will supply fluid Permits cell migration Becomes involved in the inflammatory pathways Packaging around organs Cushions and stabilises organs
Why are fibroblasts important in the immune system?
They are cells involved in healing process and responsible for scar formation.
How are myofibroblasts different to fibroblasts?
Myofibroblasts are modified fibroblasts that contain actin and myosin. This allows the healing cells to pull together; causing contraction of the wound to close.
What is the role of a macrophage?
They are monocyte derivatives that move in areolar loose tissue (not blood) which phagocytose and become APC to T lymphocytes.
What is the role of a mast cell?
Contain many granules: histamines, anticoagulants, cytokines.
They mostly react to allergens by crosslinking their IgE & allergen which releases the granules = oedema.
What are the different types of adipose tissue and give their functions?
White adipose = 1 lipid droplet with peripheral nucleus which acts as padding, shock absorber, insulation and energy store.
Brown adipose = >1 lipid droplet with central nucleus which provides insulation and energy storage. NOT PROTECTION.