healing and repair Flashcards
- Definition of regeneration
replacement of damaged cells by cells of the same type.
Differentiate between labile, stable and permanent cells
labile are constantly dividing in cell cycle and being replaced e.g. bone marrow, epidermis
Stable cells are cells that can re-enter the cell cycle e.g. parenchymal cells, liver, pancreas, kidney, smooth muscle
permanent cells are cells that cannot continue to divide once terminally differentiated e.g. skeletal, cardiac and neural.
Definitions of repair and granulation tissue
Repair is organisation by the formation of tissue.
granulation tissue is fibroblastic proliferation and Angiogenesis
List Factors delaying repair
differentiated into 2 types General and Local.
General
.Age
.Nutrition
.Steroids
Local
.Poor blood Supply
.foreign material
.Excess mobility
.Poor apposition
.Previous scarring
.Infection
.Presence of tumour
Compare and contrast the steps in cutaneous wound healing via primary and secondary union
PRIMARY UNION
Immediately: - Blood, fibrin fill cleft of wound.
1 – 3 hours: - Mild acute inflammation at edges.
- Migration of epithelial cells begins beneath surface blood clot.
2 – 3 days: - Macrophages remove blood clot.
- Epithelial covering continuous but thin.
- Granulation tissue and fibroblast activity.
- Wound contraction due to myofibroblasts.
10 – 14 days: - Epithelial covering complete.
- Scab loosens.
- Weak fibrous union present.
Late: - Strengthening of fibrous union.
- Devascularisation.
- Remodelling of collagen.
SECONDARY UNION
Immediately: - Cavity fills with blood.
Carcinogenesis 41
1 – 3 hours: - Acute inflammation in adjacent living tissue.
2 – 3 days: - Beginning of epithelial growth at edges down into crater.
- New capillary loops in base of wound
- Macrophages begin removing blood clot, necrotic tissue and debris.
- Wound contraction.
10 – 14 days: - Granulation tissue and fibrosis in base.
- Surface debris is cleared.
Late: - Full thickness epithelium restored.
- Collagenous scar in dermis.
List the complications of secondary union
Contractures especially where loss of tissue is extensive
.Keloid formation
.Pyogenic granuloma
.Infection
.Dehiscence
.Malignant change
Discuss regeneration and repair in the central nervous system
No regenaration occurs in the nervous system because neurons are permanent cells
Discuss the process of regeneration and repair in the peripheral nervous system, with possible
complications of this process listed
Briefly discuss regenerative and repair properties of muscle
Repair by fibrosis
Very limited regenerative capabilities
Stem cell transplants
Cardiac remodelling
End stage is replacement by FIBROUS TISSUE (SCAR)
List causes of pathological fractures
Differ into local bone disease and general skeletal Disease
Local Bone Disease
.Infections
.Benign neoplasms
.Mechanical
.Malignant neoplasms
General skeletal muscle
.Congenital
.Metabolic
.Disseminated neoplasia
.Mechanical
Classify fracture patterns
Transverse oblique
butterfly
spiral
comminuted
segmental
greenstick fractures
List the stages of fracture healing
.week 0- Haematoma & bone necrosis
.Week 1- Inflammation
.Week 2-4- Formation of provisional callus
Week 5-12- Definitive Callus formation
Months Remodelling according to stress
List the complications of fractures
Types of Union
Fibrous union, Non-union and delayed Union.
Define dystrophic calcification, and list examples of sites where it can occur
This is the deposition of calcium in dead or degenarate tissue.
occurs in:
caseous necrosis
Dead parasite
Fat Necrosis
Infarcts
Thrombi
Scar tissue
Atherosclerotic vessels
Degenerate or necrotic tumours
Define metastatic calcification and list possible causes and sites where it can occur
Metastatic calcification is the deposition of calcium in originally normal tissue
causes:
Primary, secondary and tertiary hyperparathyroidism
.Vitamin D intoxication Disseminated bone disease.
Sites
.Visceral
.Vascular
.Soft tiss
