Pathology Book Flashcards
(135 cards)
Types of necrosis
Coagulative - denaturing of intracytoplasmic proteins- occurs after ischaemia except brain- tissue becomes firm and swollen
Colliquative- seen in brain - hypoxia
Caseous - tuberculosis
Fat- trauma to apdipsoedue to lipase
Fibrinoid - arteriole smooth muscle wall due to malignant HTN
Cause of inflammation cellular wise
Contraction of endothelial cytoskeleton in venules
Due to release of chemical mediators
Main cell in acute inflammation
Neutrophil
Main cell in chronic inflammation
Macrophages
IL1,2 IF and TNF fucntion
IL1 neutrophil adhesion
IL2- differentiation of B and NK cells
IF- activation of macrophages and NK cells
TNF- fever, neutrophil adhesion
What is formed at inflammation sites that can limit spread of pathogen
Fibrin
What is a histological diagnostic feature of acute inflammation
Neutrophil polymorphs
Sequale of acute inflammation
Resolution - minimal injury, stimulus removed
Organisation - delayed removal of exudate
Suppuration - abscess, large quantity of dead neutrophils
Progression to chronic inflammation- usually when inadequately managed
Causes of chronic inflammation generally
Persisting infection
Prolonged exposure to non biodegradable substances
AI conditions
Vascular changes in chronic inflammation
Angiogenesis
Cells in chronic inflammation
Macrophages
Plasma
Lymphocytes
Resolution of chronic inflammation
Healing by fibrosis
What is a granuloma
Aggregation of macrophages
Large giant cells found at periphery
How TNFa induces apoptosis
TNF-alpha binds to both the p55 and p75 receptor
Reversible cell injury microscopically
Cellular swelling
Swelling of cell and organelles
Blebbing of plasma membrane
Detachment of ribosomes from ER
Clumping of chromatin
Fatty changes - hypoxic injury- in cells involved in and are unable to fat metabolism- hepatocytes and myocardial cells
Ulcer associated with burns
Curling
Microscopic changes in irreversible cell damage
Swelling and disruption of lysosomes
Presence of large amorphous densities in swollen mitochondria
Membrane disrupted
Which organelle is self replicating
Mitochondria
Which pigment is involved in ageing cells
Lipofuscin
Phases of bone healing
Reactive - haematoma forms
Fibroblasts, macrophages and new vessels invade area forming granulation tissue
Reperative- osteoblasts and chondroblasts in haematoma forming woven bone and fibrocartilage forming callus
Woven bone is replaced by lamellar bone
FInal- lamellar bone is replaced by compact bone
Hypertrophic vs keloid scars
Hypertrophic - within margins of wound - thick raised scar
Keloid- extend margins
Collagen in wound healing
Type 3 in early phase
1 in maturation phase, which is stronger
Rule of closing the abdomen
Suture 4x length of wound
1cm deep and apart
Primary vs secondary intuition of wound healing
Primary- margins closely brought together
Secondary- margins not apposed
Granulation tissue forms that contracts
Mylofibroblasts contract reducing scar size