L4-7 Inflammation and healing Flashcards
(22 cards)
Cardinal signs of acute inflammation
- Rubor (redness)
- Tumor (swelling)
- Calor (warmth)
- Dolor (pain)
- Loss of function
3 tissue changes in acute inflammation (pathway)
- Alteration of vasculature leading to increased BF
- Vascular dilatation
- Increased membrane permeability - Exudation of fluid and plasma
- Edema - Migration and activation of leukocytes
- Margination, rolling and adhesions of leukocytes
- Transmigration across endothelium
- Movement towards chemotactic molecules
4 sequelae of acute inflammation
- Complete resolution
- Healing by scarring
- Suppuration
- Chronic inflammation
Difference between acute and chronic inflammation in terms of cells involved
Acute: neutrophils and macrophages
Chronic: lymphocytes, plasma cells and macrophages
Sometimes GRANULOMAS
5 characteristics of granulomatous inflammation
- Aggregates of macrophages (epithelioid histiocytes)
- Multinuclear giant cells
- Plasma cells
- Necrosis / no necrosis
- Rim of lymphocytes
Example of caseous and non-caseous granulomatous inflammation
Caseous: TB
Non-caseous: Crohn disease
3 stimuli of granulomatous inflammation
- Persistent T-cell response
- Immune-mediated (type IV)
- Foreign body
3 outcomes of healing and repair
- Resolution
- Regeneration
- Repair by fibrosis (scarring)
Examples of labile cells
- Epidermis
- Epithelium of GIT
- Bone marrow
Examples of stable cells
- Liver
- Renal tubules
Examples of permanent cells
- Neuronal cells
- Heart muscles
What are the 4 main components of repair by connective tissue fibrosis?
- Angiogenesis
- Migration of fibroblasts
- Deposition of ECM and collagen synthesis
- Maturation and organisation of fibrous tissue
5 steps of angiogenesis
- Degradation of basement membrane of parent vessel to allow formation of capillary sprout
- Migration of endothelial cells towards angiogenic stimulus
- Proliferation and maturation of endothelial cells + lumen formation
4.Recruitment of periendothelial cells for support and maintenance
What are the characteristics of a wound that undergoes healing by first intention
- Wounds with opposed edges
- Minimum tissue loss
- Rapid rate of healing
- Minimal granulation tissue
- Minimal scarring
- Low risk of infection
What happened within the first week of healing by first intention?
- Recruitment of neutrophils to the site of injury
- Formation of vascular granulation tissue
- Capillary proliferation
- Migration and proliferation of fibroblasts
- Re-epithelialization
What happened after the first week of healing by first intention?
- Retreat of capillaries
- Return of inflammatory cells into the circulation
- Remodelling of collagen network and maturation of fibrous scar
What are the characteristics of a wound that undergoes healing by second intention
- Open wound edges
- Extensive tissue loss
- Slow rate of healing
- More granulomatous tissue
- More scarring
- High risk of infection
What happens during the first 2 weeks of healing by 2nd intention
Rapid proliferation of vascular granulomatous tissue at the base of the ulcer, with an underlying zone of hyperaemia and overlying zone of necrotic debris
What happens after the formation of granulomatous tissue in the healing of 2nd intention?
- Contraction of scar tissue, pulling opposing edge together
- Re-epithelialisation
- Sloughing off of the scab
What are the 3 characteristics of the scab left behind by the healing of 2nd intention?
- No skin appendages
- Thin layer of overlying dermis
- Surface appearance of a puckered, pale and depressed scar
5 local factors that retard wound healing
- Movement and tension of the wound
- Ischemia
- Infection
- Foreign body
- Radiation
7 systemic factors that retard wound healing
- Blood disorders (anaemia. coagulation disorders)
- Collagen disorders (OI, EDS)
- Deficiency of vitamin C
- DM
- Cancer
- Old age
- Drugs