MoD Flashcards
What are the reversible changes caused by Hypoxia?
- Low ATP causes Na to accumulate in cell causing swelling
- Chromatin clumping due to decrease in pH caused by increased anaerobic respiration
- Blebbing
What are the irreversible changes caused by Hyposia?
- Massive accumulation of Ca
- Nuclear changes
- Lysosome rupture
Define Necrosis
Changes that occur after cell death in living tissue
What is Coagulative Necrosis? What tends to cause it?
Firm tissue, produced when there is more protein denaturation than enzymes released. Cellular architecture is preserved so get ‘Ghost Outline’.
Tends to be caused by infarcts
What is Liquefactive Necrosis? What tends to cause it?
Tissue is Liquid + pus like, more enzymes released than protein denaturation. Tissue is lysed + disappears.
Tends to be caused by infection
What is an Infarct?
Necrosis due to Ischemia
What is a White Infarct (Anaemic Infarct)? Where can it be found?
Caused by the occlusion of end artery with no peripheral blood vessels.
Found in Heart, Kidney + Spleen
What us a Red Infarct (Hemorrhagic Infarct)? Where can it be found?
Caused by the occlusion of an artery in an area that has dual or collateral circulation.
Found in ‘Loose tissues’ Lungs, Small intestines, testis + ovaries
What is Hereditary Angio-Oedema
Caused by deficiency of C1 inhibitor, this normally inhibits both C1 + Bradykinin. Uninhibited Bradykinin increased the permeability of the endothelia causing oedema. Treated with C1 inhibitor infusion
What is Chronic Granulomatous Disease?
Recessive Sex linked, Immune Phagocytes can’t form ROS, can’t kill bacteria and form Granulomas to attempt to contain the bacteria
What are the effects of Chronic Inflammation?
- Fibrosis (Gall bladder [Chronic cholecystitis], Chronic peptic ulcers, cirrhosis)
- Impaired function (Chronic Inflammatory Bowel Disease)
- Atrophy
- Stimulation of immune response (Macrophage-Lymphocyte interactions)
When are Macrophages important? What are their functions?
Important in Acute + Chronic Inflammation
Functions are;
- Phagocytosis + destruction of debris + bacteria
- Presenting antigens to immune system
- Synthesis of cytokines, complement, clotting factors + proteases
- Control of other cells via cytokine release
When are Lymphocytes important? What are their function?
Important in Chronic inflammation
Functions are;
- B cells produce antibodies
- T cells - T helper + T killer cells
What are the 3 types of Giant cells and when are they found?
Langerhans - TB (Peripheral Nuclei)
Foreign Body Type (Central Nuclei)
Toulon - Fat Necrosis (Ring of Nuclei)
What is Rheumatoid Arthritis?
Autoimmune disease where localised chronic inflammation leads to joint destruction
Describe the formation of Granulation Tissue
- Cell Migration - Inflammatory cells (Neutrophils, Macrophages - Phagocytosis. Lymphocytes, Macrophages - Chemical Mediators), Endothelial cells (Angiogenesis), Fibroblasts/Myofibroblasts
- Angiogenesis - Development of new blood supply. Endothelial proliferation induced by proangiogenic growth factors, e.g. VEGF
- Extracellular Matrix - Supports + anchors cells, Sequesters growth factors
Describe Fibrous Repair
- Inflammatory cell infiltrate - Blood clot forms. Acute inflammation around edges. Chronic inflammation - Macrophages + lymphocytes migrate into the clot
- Clot replaced by Granulation Tissue - Angiogenesis, Myo/fibroblasts migrate + differentiate
- Maturation - Cell population falls, collagen increases, Myofibroblasts contract, vessels differentiate + are reduced
What causes the breakdown of Fibrin? What fibrinolytic is widely used and how does it work?
Plasmin causes breakdown of fibrin.
Streptokinase activates Plasminogen
What is the treatment for Deep Vein Thrombosis?
- IV Heparin (Anticoagulant)
- Oral Warfarin (Interferes with synthesis of Vit. K clotting factors)
What can cause Fat Emboli?
- Fractures of Long Bones
- Lacerations of adipose tissue
What can lead to a Cerebral Embolism?
Atrial Fibrillation causes Stasis of blood in atria, causes a thrombus which can go to the brain and cause a stroke
What can be the triggers for Disseminated Intravascular Coagulation?
Infection, trauma, liver disease
What is Thrombocytopenia?
Platelet count way below reference range, usually accompanied by a bone marrow disfunction (e.g. Leukaemia, anaemia)
Name the risk factors for Coronary Heart Disease
- Male
- Smoking
- Hypertension (increased epithelial damage)
- Diabetes
- Alcohol
- Infection (H. pylori)
What is an Atheroma?
The accumulation of intracellular + extracellular lipid in the intima and media of large + medium sized arteries
