fibrosis Flashcards
acute inflammation
which are characterized by rapidly resolving vascular changes, oedema and neutrophilic inflammation
fibrosis
typically results from chronic inflammation — defined as an (immune) response that persists for several months and in which inflammation, tissue remodeling and repair processes occur simultaneously.
END STAGE DISEASE
organ is about to die
Healing pushed past its limit
Cause of injury persists
Or success in repair is not recognised
Chronic inflammatory cell populations persist
Functioning tissue is replaced by collagenous scar tissue AND FIBROSIS
Fractures and wound healing
- Involves cell death
* Acute and chronic inflammation • Rebuilding/regeneration/ remodeling of bone
Bone healing & remodeling after fracture
- Bone remodeling is a continual process throughout life.
- Osteogenic cells in the periosteum of the bone respond to trauma or stress to the bone.
- Stress to the bone: osteogenic cells secrete more osteoid to form new bone tissue on the outside to form new layers of bone tissue.
- At the same time, the osteoclasts in the endosteum enzymatically breakdown bone tissue to maintain the thickness of the bone and to make the medullary cavity large enough.
What causes bones to fracture easily and impairs healing in bone (pathological causes of bone fracture)?
Osteomalacia (in children this condition is called Rickets)
Osteoporosis
Tumour
Osteomalacia
Softening of the bone Deficiency of vitamin D
Failure to replace the turnover of calcium and phosphorus in the organic matrix of bone.
FACTORS THAT INFLUENCE HEALING:
Nutrition, age, adequate blood supply (atherosclerosis), disease (diabetes), hormones (glucocorticoids).
Infection, mechanical factors (movement around wounds), foreign bodies (sutures, glass, splinters), size and location (small cut vs blunt trauma)
Inadequate healing leads to rupture and/or ulceration.
Excessive healing leads to mounds of collagen called keloids (hypertrophic scar)
SUMMARY: INJURY and REPAIR
repaired completely (via resolution), it can wall off (abscess, ulcer), or organisation and scarring (with regeneration & fibrosis) occur