Download I. Regressive Changes. The types of Necrosis.

NECROSIS, GANGRENE.
I. practical training
2rd year Dentistry
Signs of death
• Cardiac arrest (no pulse)
• Pallor mortis, paleness which happens in the 15–120 minutes after
death
• Livor mortis, a settling of the blood in the lower (dependent) portion
of the body
• Algor mortis, the reduction in body temperature following death. This
is generally a steady decline until matching ambient temperature
• Rigor mortis, the limbs of the corpse become stiff (Latin rigor) and
difficult to move or manipulate
• Decomposition, the reduction into simpler forms of matter,
accompanied by a strong, unpleasant odor.
• Diffusion of the liquid and gasses from the intestine –
pseudomelanosis, verdohemoglobin
• Cell Autolysis – destruction of lysosomes
Vital reaction
• Inflamation –
(redness, white blood cells - polymorfonuclears,
lymfocytes, plazmocytes, macrofages)
• Demarcation
• Reparation
Regresive changes
• Deth, necrosis, apopthosis, dystrophy
•
Apoptosis – is the process of programmed cell death
that may occure in multicellular organism and leads to
characteristic cell changes and death of the cell
- the programmed destruction of cells during
embryogenesis
- cell death injury – DNA demage, drug injury
(cytostatics), cell death in tumours
Morfology – cell shrinkage, chromatin condensation,
formation of the cytoplasmatic blebs and apoptotic
bodies
Regresive changes
• Necrosis – cell death in living tissue, results form
the progressive degenerative reaction of
enzymes on the lethaly injured cell
Morfology – increased eozinophilia, nuclear
changes (karyolysis, pyknosis (nuclear
shrinkage and increased basophilia)
Ethiology – microorganisms, chemicals, physical
factors,
Necrosis
• Coagulative - is a type of accidental cell death typically caused by
ischemia or infarction. Injury denatures structural proteins as well as
lysosomal enzymes thus blocking the proteolysis of the damaged
cells. (In tissues rich for proteins – typicaly infarction of myocardium)
• Liquefactive - In liquefactive necrosis, the affected cell is
completely digested by hydrolytic enzymes, resulting in a soft,
circumscribed lesion consisting of pus and the fluid remains of
necrotic tissue. Sometimes it is associated with focal bacterial or
fungal infections. Typical for tissues poor for proteins – ischemic
brain nekrosis
• Gangrenous - this term is used in clinical surgical practice. Usually
aplied for limbs, mumiffication (dry gangrene), modiffication by
microorganisms (wet gangrene)
Necrosis
• Caseous – in foci of tuberculous infection, name form white gross
appearance of the area of necrosis. Microscopicly – acellular pink
areas of necrosis surrounded by a granulomatous inflammatory
process. In necrosis – amorphous granular debris composed of
fragmented coagulated cells
• Zenker´s necrosis – muscles, influensa infection
• Fat necrosis (Balzer´s) – in which the neutral fats in adipose tissue
are split into fatty acids and glycerol, usually affecting the pancreas
and peripancreatic fat in acute hemorrhagic pancreatitis.
• Fibrinoid - accumulation of amorphous, basic, proteinaceous
material in the tissue matrix with a staining pattern reminiscent of
fibrin. (vasculitis, gastric ulcer)
Recent myocardial infarction
Recent myocardial infarction
Coagulative necrosis– myocardial
infarcrion
Older myocardial infarction
Older myocardial infarction
Postinfarction scar of the myocard
Postinfarction scar of the myocard
Renal infarct
Caseous tbc lymphadenitis
Cerebral infarct (encephalomalacia)
Cerebral infarct (encephalomalacia)
Lung tromboembolism and haemorrhagic infarct
Fibrinoid necrosis
gastric ulcer
revmatoid artritis
Liquefactive necrosis – brain
Gangrena
Secondary modified necrosis
Dry (mumification) – drying up of necrotic parts – diabetes
patient´s legs (hematin), fetus papyraceus
Wet (sfaceus, humida) – modified by bacterias
Emphysematous (emfyzematóza) – anearobic bacterias –
Clostridia, toxins
Gangrene of foot