Cell and tissue Injury Flashcards
steatosis
fatty change - abnormal retention of lipids
oncosis
hydropic change
Tell me about necrosis
often effects solid masses of tissue evokes an inflammatory response takes out cell groups cell membrane integrity becomes lost cell swelling and lysis Dead cells are phagocytksed by inflammatory cells abnormal iron homeostasis
What are the different types of necrosis
coagulate colliquative caseous gangrenous fibrinoid fat necrosis
What causes reduced apoptosis
neoplasia
autoimmune disease
virus infection
what causes increased apoptosis
neurogenrative disorders
HIV infection of T-Lymphocytes
what is coagulative necrosis
This is the most common type
coagulation of cellular proteins
initially firm but then soft
colliquative
liquefaction with formation of cystic spaces
proteolysis dominates over coagulation
caseous necrosis
TB
Gangrenous necrosis
necrosis with putrefaction (rotting)
mostly in appendages
fibrinoid necrosis
malignant hypertension
blood vessels
pyroptosis
associated with salmonella infection, is apoptosis then develops into necrosis
Healing
complete resolution
labile tissues
blood, skin, gut
stable tissues
liver, kidney
permanent
neurones, skeletal muscle
Healing by primary intension
this is when minimal damage has occurred as little to no tissue has been lost: This allows regeneration of scar tissue, apposed edges of wound join by a thin layer of fibrin, ultimately replaced by collagen
Healing by secondary intension
This is when there is significant tissue loss
new blood vessels are laid down along with granulation tissue
what is granulation
this is an intermediate substance: - loops of capillaries - collagen - inflammatory cells organises then deposition of collagen and contraction
How do you tell the difference between healing by primary or secondary intension
wound contraction in the presence of myofibriblasts
3 steps in bone healing
repair
remodelling
resolution
Wound strength
sutures usually removed after the end of week 1
strength increases rapidly over the next 4 weeks
by the third month 70-80% strength should be restored
What factors effect wound healing
systematic: age nutrition metabolic status circulatory status hormones Local: infection mechanical factors foreign bodies size, location and type of wound
What are signs of an abnormal wound
deficient scar formation -reopening (dehiscence) -ulceration excessive formation o repair components -keloid scar (red and raised) formation of contractors -exaggerated contraction -deformity of the wound and surrounding tissues
