Connective tissue Flashcards
Embryological origin
Mesoderm
What are the 3 basic components of all connective tissue
Cells
Ground substance
fibres (together with ground substance are extracellular matrix)
Collagen properties
Types use pneumonic
flexible non branching fibres regularly arranged many different types Type 1: Bone Skin Tendons Type2: cartilage Type3: reticular fibres and blood vessels Type 4: Basement membrane
What makes collagen
Produced by fibroblasts
What are reticular fibres
delicate fibres of type III collagen
forms supportive mesh network around many many soft tissues such as liver and secretory cells
What are elastic fibres?
What produces them?
What are there properties?
Allow connective tissue to stretch and recoil back to original shape
found in walls of arteries and in the alveoli of the lung
Composed of fibrillin backbone laid down by fibroblasts
Then impregnated and surrounded by elastin
Short branching fibers
What is ground substance? What produces it?
mainly water viscous substance found between fibres and cells
Fibroblasts
What is the function of ground substance?
acts as a lubricant and barrier to invading microorganisms
What is ground substance comprised of
long unbranched polysaccharide chains, glycosaminoglycans glycoproteins and proteoglycans
What is the main GAG in loose connective tissue?
hyaluronic acid
What are fibrobalsts
Essential cell in consecutive tissue
produce ground substance and fibres
spindle shaped cells with a cigar shaped nucleus
In their inactive form they are call fibrocytes
In bones osteoblasts
in cartilage chondroblasts
What are adipocytes
What do they look like
Fat cells
Very large cells
signet shaped
nucleus peripherally located large unilocular fat globule
What is white adipose tissue and its function
Consists of many unilocular white adipocytes
Acts as a energy store
What is brown adipose tissue? What is its function
Brown adipocytes are mupltilocualr cells contain many more mitochondria
Role in thermogenesis and generation of heat important in neonates
Macrophages function?
Shot lived
Differentiate in connective tissue enter from blood via diapedesis
Antigen presentation and immunoprotection as well as phagocytosis of cellular debris
What is the function of mast cells?
Secrete and produce histamines
trigger and immune response
Where would you find loose arerolar connective tissue?
Surrounding blood vessels basement mebrane
Properties and function of loose areolar connective tissue
largely ground substance and some fibroblasts and mainly reticular fibres (depends on location)
Ideal for exchange of nutrients between blood and tissues
acts to absorb shock and bind tissues together
is not resistant to stress
What is dense connective tissue
A lot less ground substance
lots more collagen and elastic fibres much fewer cells
What is dense irregular connective tissue? Where is it found?
Collagen fibres are arranged randomly
resistance in all directions
found in capsules surrounding organs
What is dense regular connective tissue? Where is it found?
Collagen fibres arranged parallel to one another
found in ligament and tendons
resits stretch in one direction
Why are tendons so slow to repair?
Lot less ground substance longer for tissue fluid and nutrients to get to cells that are damaged
What is Ehlers Danlos syndrome?
Faulty cologne production that leads to hyper-mobility of joints
Dependant on subtype can shorten lifespan increased flexibility of blood vessels prone to anyerusums
What is Marfans -syndrome?
mutation in fibrillin gene
faults elastic fibre production and formation of many other connective tissues
usually have very long arms and fingers
weak blood vessels prone to anyerusms
