Connective Tissues Flashcards
What are the functions of Connective tissues?
- Wound healing
- Connecting (support/forming organs)
- Transportation (Provide medium for diffusion)
- Storage (As adipose)
- Protection (Insulate as adipose)
- Defence (against infection with lymph and blood)
What is general connective tissue made of?
Cells; Fibres (Collagen/Reticulin/Elastin); Ground Substance
What is
A) Ground substance
B)A proteoglycan
A)Viscous clear substance made of proteoglycans
B) A proteoglycan is a molecule made of a core protein bound to a GAG (glycosaminoglycan) by linker proteins
What do GAGS bring to ground substance?
They are hydrophilic and allow fast diffusion. They also resist compression.
What is the GAG in cartilage ground substance and how does it give cartilage its properties?
The GAG in cartilage ground substance is hyaluronic acid and turgor in the cartilage allows it to resist compression, without inhibiting flexibility.
What is the ECM?
The extracellular matrix is a collection of extracellular molecules secreted by cells that provide structure and support; it is made by ground substance and fibres.
What are characteristics of LOOSE connective tissue?
- Many Cells
- Abundant ground substance
- Viscous
- Under epithelia location
- Around blood vessels location
- Sparse collagen fibres
What are characteristics of DENSE connective tissue?
- Few cells
- Lots of collagen fibres
- Can be regular to irregular
Regular DENSE CT
Parallel bundles of collagen fibres
Designed to withstand stress in one direction
Tendons/Ligaments/Aponeurosis
Irregular DENSE CT
Collagen fibres in different direction
Designed to withstand stress in many directions
Found in submucosa/deep layers of the dermis
CT Cell types
Fixed:
Fibroblasts; Melanocytes; Mast cells; Adipocytes; Macrophages
Wandering immune:
Leukocytes; Plasma cells; Monocytes; Eosinophils/Basophils
What do fibroblasts do?
They synthesise Ground Substance (fibres). They secrete procollagen and are important in wound healing and scar tissue formation. Fibroblasts with actin are called myofibroblasts.
Macrophages are……..?
Phagocytic and are APCs.
Mast Cells…….?
Contain granules with histamine; heparin; eosinophil and neutrophil attracting substances. They are not found in the CNS in case of damage. Contents are released when IgE (immunoglobulin E coating the master cells) crosslinks with allergens.
