Cell Pathology Flashcards
(46 cards)
Give 2 causes of generalised oedema.
Increased hydrostatic pressure (e.g. due to heart failure)
Reduced plasma oncotic pressure (e.g. due to reduced albumin).
Give 3 causes of a thrombus.
Endothelial injury Static or turbulent blood flow Blood hypercoagulability (can be genetic or acquired).
Compare the composition of a pale thrombus and a red thrombus.
A pale thrombus is composed of fibrillin and platelets. Red thrombi are made from fibrillin, platelets and red blood cells.
Describe a venous thrombus.
Composed of RBCs + platelets. Occlusive thrombus due to sluggish blood flow. Veins of lower extremities most commonly affected.
Describe an arterial thrombus.
Composed of RBCs, platelets, leukocytes + fibrillin. Occlusive thrombus superimposed on atherosclerotic plaques (atherosclerosis leads to endothelial injury and abnormal blood flow). Mostly in coronary, cerebral and femoral arteries.
What is an embolus?
Abnormal material within the circulatory system which is carried in the blood to a site distant from its point of origin. 90% arise from thrombi.
Apart from thrombi, give examples of other types of emboli.
Gas (interventional procedures, divers) Fat (fractures) Tumour Amniotic fluid (childbirth) Foreign Material (IVD user).
What is infarction?
Necrosis due to ischaemia.
What are red infarcts?
Occur due to venous occlusion. Occur in loose tissues (e.g. lungs). Occur in organs with dual circulation (lung, bowel).
What are white infarcts?
Occur due to arterial occlusion in dense/solid organs.
What is shock?
Systemic hypotension due to reduced circulatory volume or reduced cardiac output resulting in tissue hypoxia.
What is acute inflammation?
A rapid non-specific response to cellular injury, allowing rapid delivery of leukocytes and plasma proteins to the site of injury.
What are 4 signs of inflammation on examination?
Redness, heat, swelling, pain.
How is vascular permeability increased by histamine?
Endothelial cells contract: increased interendothelial spacing.
What is the transudate?
Fluid pushed through capillary walls due to high hydrostatic pressure.
What is the exudate?
What leaves blood vessels due to ‘leaky’ vessel walls.
Which leukocytes are most important in the initial phase of typical acute inflammation?
Those which phagocytose (neutrophils and macrophages) which kill the bacteria and eliminate foreign and necrotic material.
Describe the termination of a typical acute inflammation.
Inflammation mediators and neutrophils have a short half-life. Macrophages, mast cells and lymphocytes produce anti-inflammatory products. The cause of cell injury is removed, so it comes to a stop.
Define chronic inflammation.
Inflammation of prolonged duration in which inflammation, tissue injury and attempts at tissue repair coexist.
What may cause chronic inflammation?
Persistent infection, prolonged exposure to toxins or autoimmunity.
What is granulation tissue?
A loose network of connective tissues and blood vessels with lots of lymphocytes, plasma cells and fibroblasts. It is made to replace damaged tissue.
Give 2 types of wound healing.
Resolution: regeneration of parenchymal cells with restoration of function.
Scarring: angiogenesis, migration and repair of fibroblasts, scar formation, connective tissue remodelling.
What is neoplasia?
Growth which continues even when the initial stimulus is removed, is independent of the body’s normal growth regulation mechanisms, and is purposeless. CANCERS ARE MALIGNANT NEOPLASMS.
What are hamartomas (hamartomatous tumours)?
Localised benign overgrowths: ARCHITECTURAL but not cytological abnormalities.
