define necrosis?
- premature death of cells
- cell degradation by lysosomal enzymes
define apoptosis?
- programmed cell death
define pykinosis?
- irreversible condensation of chromatin in nucleus
define karyorrhexis?
- fragmentation of nucleus
define ischaemia?
lack of blood supply to and organ
define infarction?
obstruction of blood supply causing death of tissue
define hypoxia?
deficiency in the amount of oxygen
define neoplasia?
presence or formation of new and abnormal growth of tissue
how does free radicals cause cells to become injuried?
- cause disruption of plasma membrane
- cause abnormal folding
- break the DNA
how does ischemia cause chromatin damage?
- anaerobic respiration cause decrease in pH and lead to clumping of nuclear chromatin
what does ischemia do to cells?
- endoplasmic reticulum swelling
- cellular swelling
- loss of microvilli
- clumping of nucear chromatin
how does ischemia cause ER swelling, cellular swelling and loss of microvilli?
- lack of ATP cause lack of sodium pump which lead to efflux of potassium and influx of calcium, water and sodium
what damage does virus do to the cell?
- neoplasmic transformation
- cell lysis or fusion
- metabolic derangements
what is colliquative necrosis?
- results in tissue becoming liquid viscous mass
- associated to bacterial or fungal
- cell digested by hydrolytic enaymes
- found in the CNS and lungs
what is coagulative necrosis?
- injury denatures the structural proteins
- lack of lysosomal enzymes allow it to maintain coagulated
what is caseous necrosis?
- dead tissue appears soft and white proteinaceous dead cell mass
- encountered in foci of TB infection
which HLA antigen cause ankylosing spondylitis?
HLA B27
which HLA antigen cause coeliac disease?
HLA DR3
which HLA antigen cause graves disease?
HLA DR3
which HLA antigen cause insulin dependent diabetes?
HLA DR3 and HLA DR4
which HLA antigen cause rheumatoid disease?
HLA DR4
