Inflammation Flashcards
Function of macrophages
Phagocytosis and destruction of debris and bacteria. Long term scavengers
Process and present antigens to the immune system (professional antigen presenting cells)
Synthesise cytokines, complement complexes, clotting factors and proteases
Controls other cells by cytokine release or cell-cell interactions
Ways chronic inflammation can come about
Stem from acute inflammation if the damage is severe
De novo (no acute phase) e.g. Autoimmune (rheumatoid arthritis), chronic infection (viral hepatitis) or chronic low level irritants
Alongside acute inflammation with severe persistent or repeated infections e.g. Chronic cholecystitis
Appearance of macrophages
Foamy cytoplasm as lots of RER, large nucleus
Function of lymphocytes
Complex, many immunological functions.
B cells differentiate to plasma cells which produce antibodies
T cells involved in control and have a cytotoxic function.
Appearance of plasma cells
Lots of cytoplasm due to abundant RER
Clock-face chromatin in the nucleus
Perinuclear hof - pale area around the nucleus
Function of plasma cells
Produce and secrete antibodies
Appearance of eosinophils
Bilobular nucleus with bright pink cytoplasm : ‘sunburnt face with shades’
Eosinophils are seen in
Allergies, parasite infestations (esp in the gut), some tumours
Function of fibroblasts/myofibroblasts in chronic inflammation
Recruited by macrophages, secrete collagen
How giant cells are made
Fusion of macrophages due to frustrated phagocytosis (too much for them to phagocytose)
Appearance of giant cells
Multinucleated, horseshoe-shaped aggregation of nuclei around the outside, abundant cytoplasm in the centre.
Types of giant cell
Touton seen in fat necrosis and xanthoma. Contains fat.
Langhans seen in TB
Foreign body
Brief overview of possible complications of chronic inflammation
Tissue destruction, excessive fibrosis, impaired function, atrophy
Microscopic and macroscopic description of chronic cholecystitis
Macro - fibrotic, redness of wall, white mucosa, multiple gallstones
Micro - Thickened muscle, lots of plasma cells, lymphocytes
Describe the cause of chronic cholecystitis
Gallstone becomes stuck in the cystic duct, irritating the gall bladder and causing multiple repeated episodes of acute inflammation
Difference in cause between acute and chronic gastritis
Acute - alcohol/drugs e.g. NSAIDs
Chronic - Heliobacter pylori
Microscopic and macroscopic appearance of gastric ulceration
Punched out area of necrosis with a central ulcer
Polymorphs and fibrin in the centre, lymphoid infiltrate
What is a fistula?
Abnormal connection between two epithelial-lined organs (usually when tubular)
Localised and systemic effects of rheumatoid arthritis
Localised - joint destruction
Systemic - affects other organs, rarely causes amyloidosis
What is a granuloma?
Aggregate of activated macrophages. Modified and immoveable. Other inflammatory cells can be involved.
Causes of granuloma
Mild irritants - artificial joints which have broken/ruptured silicone implant
Infections - mycobacterium (TB/leprosy), other (fungi, rare)
Unknown - sarcoidosis, Wegener’s granulomatosis, Crohn’s disease
Cardinal signs of inflammation
Rubor, calor, dolor, tumor and loss of function
Describe the changes to blood flow in acute inflammation
Transient vasoconstriction of arterioles
Vasodilation of arterioles then capillaries, increasing blood flow which causes heat and redness.
Increased permeability of blood vessels causing exudation of protein-rich fluid and slow circulation as blood is thicker.
Vascular stasis
Describe the meaning of vascular stasis
Concentration of erythrocytes increases