ICS Flashcards

Question

What is the complement system

Answer 1

to remove or destroy antigen, either by direct lysis or by opsonisation (the enhancement of phagocytosis by factors (opsonins) in plasma.

Answer 2

Activated factor XII and plasmin activate the conversion of prekallikin to kallikrein. This stimulates the conversion of kininogens to kinins, such as bradykinin (causes vasodilation). Prekallikrein can also be activated by leucocyte proteases e.g trypsin:

Answer 3

The terminal lymphatics drain in collecting lymphatics, which have valves and so propel lymph passively, aided by contracting of neighbouring muscles, to the lymph nodes - In acute inflammation the lymphatic channels become dilated as they drain away the oedema fluid of the inflammatory exudate - Antigens are carried to the regional lymph nodes for recognition by lymphocytes

Answer 4

On stimulation by the C3a/C5a complement components they release preformed inflammatory mediators (i.e. histamine) stored in their granules and metabolise arachidonic acid into newly synthesised inflammatory mediators such as leukotrienes, prostaglandins and thromboxanes

Answer 5

Dilution of toxins Entry of antibodies Transport of drugs to the site where bacteria are multiplying Fibrin formation from exuded fibrinogen which may impede the movement of microorganisms thereby trapping them and thus facilitating phagocytosis. Delivery of nutrients & oxygen Stimulation of immune response

Answer 6

Digestion of normal tissues Swelling Inappropriate inflammatory response - IgE

Answer 7

Pyrexia - fever Neutrophil polymorphs & macrophages produce compounds known as endogenous pyrogens which act on the hypothalamus to set the thermoregulatory mechanisms at a higher temperature Also anorexia, nausea and weight loss

Answer 8

Cytokine IFN-gamma via classical pathway activate macrophages

Answer 9

Secrete IL-4, 5 and 13 Via alternate pathway Activate macrophages and eosinophils

Answer 10

Secrete IL-17 Recruit neutrophils and monocytes

Answer 11

The subsequent and prolonged tissue reactions to injury following the initial response OR inflammatory process which lymphocytes, plasma cells and macrophages predominate

Answer 12

- Resistance of infective agent to phagocytosis - tuberculosis, leprosy - Endogenous - necrotic adipose tissue bone -Exogenous - Silica, asbestos - Autoimmune diseases e.g. rheumatoid arthritis or hashimotos thyroiditis - Specific diseases of unknown aetiology - chronic ibd - Primary granulomatous diseases - chrons - Transplant rejection -Acute inflammation

Answer 13

suppurative type - if the pus forms an abscess cavity that is deep-seated, and drainage is delayed or inadequate, then by the time that drainage occurs the abscess will have developed thick walls composed from granulation and fibrous tissues.

Answer 14

- Chronic ulcer: * Such as a chronic peptic ulcer of the stomach with breach of the mucosa - Chronic abscess cavity: * For example osteomyelitis - Thickening of the wall of a hollow organ - Granulomatous inflammation: * Occurs when the immune system attempts to wall off substance but is unable to eliminate it, this forms a granuloma (a collection of epithelioid histiocytes (a stationary phagocytic cell (macrophage) found in tissue) - Fibrosis: * Thickening or scarring of connective tissue

Answer 15

The cellular infiltrate consists characteristically of lymphocytes, plasma cells & macrophages. A few eosinophil polymorphs may be present but neutrophil polymorphs are scarce Some of the macrophages may form multinucleate giant cells Exudation of fluid is not a prominent feature, but there may be production of new fibrous tissue from granulation tissue There may be evidence of continuing destruction of tissue at the same time as tissue regeneration and repair Tissue necrosis may be a prominent feature, especially in granulomatous conditions such as tuberculosis

Answer 16

angiogenesis (formation of new blood vessels) followed by fibroblast proliferation and collagen synthesis resulting in granulation tissue

Answer 17

angiogenesis (formation of new blood vessels) followed by fibroblast proliferation and collagen synthesis resulting in granulation tissue

Answer 18

Regeneration of epithelial cells

Answer 19

regeneration of epithelial cells

Answer 20

Stim fibroblast proliferation and collagen synthesis. Controls epithelial regeneration

Answer 21

Mitogenic and chemotactic for fibroblasts and smooth muscle cells

Answer 22

Stim fibroblast proliferation, angiogenesis and epithelial cell regeneration

Answer 23

Synergistic effect with other growth factors

Answer 24

Stim angiogenesis

Answer 25

B lymphocyte - Which on contact with antigen, become progressively transformed into plasma cells (cells specially adapts for the production of antibodies) T lymphocyte - cell-mediated immunity * On contact with antigen, produce a range of soluble factors called cytokines, with important activities, such as the recruitment & activation of other cell types e.g macrophages etc.

Answer 26

move by amoeboid motion through the tissues and respond to certain chemotactic stimuli. Macrophages can ingest a wider range of materials then can polymorphs and, being long-lived, they can harbour viable organisms if they are unable to kill them by their lysosomal enzymes When macrophages participate in the delayed-type hypersensitivity response to these types of organism, they often die in the process, contributing to the large areas of necrosis by release of their lysosomal enzymes Macrophages in inflamed tissue are derived from blood monocytes that have migrated out of vessels and have become transformed in the tissues they are thus part of the mononuclear phagocyte system also known as the reticuloendothelial system.

Answer 27

an aggregate of epithelioid histiocytes TUBERCULOSIS most common

Answer 28

Use Ziehl-neelson stain and will be bright red

Answer 29

Specific infections - mycobacteria Materials that resist digestion Specific chemicals - beryllium Drugs Unknown - chrons and sarcoidosis

Answer 30

form where particulate matter that is indigestible by macrophages accumulates when two or more macrophages attempt simultaneously to engulf the same particle; their cell membranes fuse and the cells unite

Answer 31

horseshoe arrangement of peripheral nuclei at one pole of the cell - Characteristically seen in TUBERCULOSIS

Answer 32

Large cells with nuclei randomly scattered throughout their cytoplasm Characteristically seen in relation to particulate foreign body material

Answer 33

Have a central ring of nuclei, peripheral to which there is lipid material Seen when macrophages attempt to ingest lipids and in xanthomas (yellowy patch, can appear anywhere on skin e.g eyelids)/dermatofibromas (fibrous nodule) of the skin

Answer 34

Acute in the response to acute myocardial infarction and the generation of some complication of MI such as cardiac rupture Chronic involved in myocardial fibrosis after MI

Answer 35

Initiation and propagation and its progression e.g. ulcerative colitis

Answer 36

macrophages adhere to endothelium, migrate into the arterial intima and, with T lymphocytes, express cell adhesion molecules which recruit other cells into the area. The macrophages are involved in processing the lipids that accumulate in atheromatous plaques

Answer 37

Multiple sclerosis with chronic demyelinating neurodegenerative disorder in which chronic inflammation

Answer 38

Exudate - high protein content due to being from increased vascular permeability Transudate low protein content due to vessels having normal permeability characteristics.

Answer 39

Labile cells Stable cell populations Permanent cells Stem cells

Answer 40

In the epidermis stem cells are found in the basal layer immediately adjacent to the basement membrane, in the hair follicles and sebaceous glands In intestinal mucosa the stem cells are near the bottom of the crypts In the liver they are found lying between hepatocytes and bile ducts There is also a separate pool of stem cells available in the bone marrow; these haemopoietic stem cells are able to seed into other organs and differentiate locally into the appropriate tissue

Answer 41

The epidermis is lost over a limited area, but at the margins of the lesion there remain cells that can multiply to cover the defect * At first, cells proliferate and spread out as a thin sheet until the defect is covered * When a confluent layer has been formed, the stimulus to proliferate is switched off; this is known as contact inhibition, and controls both growth and movement * Once in place, the epidermis is rebuilt from the base up until it is indistinguishable from normal - this whole process is called healing

Answer 42

The repair of specialised tissues by the formation of a fibrous scar. It occurs by the production of granulation tissue and the removal of dead tissue by phagocytosis.

Answer 43

Loops of capillaries supported by myofibroblasts which actively contracts to reduce wound size; this may result in a structure later.

Answer 44

NSAIDS, antibiotics, antifungal, aspirin etc

Answer 45

1st detention – can suture up the cut Incision -> exudation of fibrinogen -> weak fibrin join -> epidermal regrowth and collagen synthesis -> strong collagen join

Answer 46

Can’t bring the skin edges together the cut is too deep Loss of tissue -> granulation tissue -> organisation -> early fibrous scar -> scar contraction Phagocytosis to remove any debris Granulation tissue to fill in defects and repair specialised tissues lost Epithelial regeneration to cover the surface

Answer 47

Initiating factor still present Tissue damaged and unable to regenerate Replacement of damaged tissue by fibrous tissue Collagen produced by fibroblasts

Answer 48

Hepatocytes Pneumocytes All blood cells Gut epithelium Skin epithelium Osteocytes – help remodel bone fractures

Answer 49

Myocardial cells Neurones

Answer 50

Glial cells instead of fibroblasts

Answer 51

Solid mass of blood constituents formed within intact vascular system during life

Answer 52

Solid mass of blood constituents formed within intact vascular system during life

Answer 53

Solid mass of blood constituents within an intact vascular system during life

Answer 54

Blood coagulated outside of the vascular system or after death

Answer 55

Laminar flow - cells travel in centre of arterial vessels and don't touch sides Endothelial cells - are not "sticky" when healthy

Answer 56

No nucleus and derived from megakaryocytes Platelets are activated and the contents of their granules released when come into contact with collagen, found in damaged vessel walls The platelets change shape and extend pseudopodia; their granules releases their contents and platelets form a mass that covers the vessel wall defect until the endothelial cells have regenerated

Answer 57

Alpha granules: * Contain several substances involved in the process of platelet adhesion to damaged vessel walls * Substances include; fibrinogen, fibronectin & platelet growth factor Dense granules: * Contain substances such as; adenosine diphosphate (ADP) that cause platelets to aggregate

Answer 58

Platelet aggregation - Platelets release chemicals when the aggregate which cause other platelets to stick to them and also which start off the cascade of clotting proteins in the blood Both these reactions involve positive feedback loops so that once they have started they are difficult to stop Once the clotting cascade has started there is formation of the large protein molecule fibrin which makes a mesh in which red blood cells can become entrapped

Answer 59

Change in vessel wall Change in blood flow Change in blood constituents Not all 3 are needed.

Answer 60

cigarette smoke damages endothelial cells resulting in both a change in vessel wall and blood flow over the injured/absent cells

Answer 61

1. Raised fatty streak on intimal surface 2. Plaque grows to protrude into lumen and turbulent blood flow 3. Turbulance results in loss of intimal cells and exposed plaque is presented to blood cells. 4. Results in fibrin deposits and platelet clumping and platelets adhere to exposed collagen 5. Platelet0growth factor in alpha granules causes proliferation of arterial smooth muscle cells which add to plaque. 6. Platelet layer and rbc become trapped in fibrin meshwork 7. Build up protrudes even further into lumen more platelet deposition 8. disrupts laminar flow and thrombi grow in direction of blood flow (propagation)

Answer 62

Atheroma do not occur due to low bp but starts at valves 1. valves disturb blood flow as protrude into vessel lumen especially if damaged by trauma, stasis or occlusion 2. if bp falls flow is slower (stasis) and thrombosis more likely through successive deposition via propagation

Answer 63

surgery when bp falls After MI elderly or those immobilised for long periods of time for DVT any individual can get DVT

Answer 64

- The loss of pulse distal to the thrombus - Area becomes cold, pale & painful - Eventually the tissue will die and gangrene results

Answer 65

The area becoming tender due to developing ischaemia in the vein wall initially, but there is also general ischaemic pain as the circulation worsens - Area becoming reddened - since blood is still carried to the site by the arteries but cannot be drained away by the veins) - Area becoming swollen

Answer 66

A - Resolves as body dissolves it B - Organised into a scar by invasion of macrophages which clear away thrombus and fibroblasts replace it with collagen C - intimal cells proliferate and small sprouts of capillaries grow into thrombus and fuse to larger vessels. Recanalised D - Fragments of thrombus may break off resulting in embolism

Answer 67

inhibits platelet aggregation and a low dose can help prevent it.

Answer 68

Inhibits vitamin K to prevent clotting

Answer 69

An embolus is a mass of material in the vascular system able to lodge in a vessel and block its lumen

Answer 70

1. thrombus 2. air 3. Cholesterol crystals 4. Tumour amniotic fluid 5. Fat

Answer 71

If an embolus enters the venous system it will travel to the vena cava, through the right side of the heart and will lodge somewhere in the pulmonary arteries (depending on its size) - resulting in a PULMONARY EMBOLISM

Answer 72

If an embolus enters the arterial system it can travel anywhere downstream of its entry point, for example: - A mural thrombus overlying a myocardial infarct in the left ventricle can go anywhere in the systemic circulation - Cholesterol crystals from an atheromatous plaque in the descending aorta can go to any of the lower limb and renal arteries

Answer 73

May occur unnoticed and be lysed within the lung * May become organised and cause some permanent, though small, respiratory deficiency - the accumulation of such damage over a long period may be the cause of so-called ‘idiopathic pulmonary hypertension’

Answer 74

May be large enough to result in acute respiratory and cardiac problems that may resolve slowly with or without treatment * The main symptoms are; chest pain and shortness of breath due to the effective loss of the area of lung supplied by the occluded vessel - the area may even become infarcted * Although many patients recover, their lung function is impaired and are at risk of further emboli in the future from the same source

Answer 75

These result in sudden death * They are usually long thrombi derived from the leg veins and are often impacted across the bifurcation of one of the major pulmonary arteries

Answer 76

ineffectual movement of the atria cause blood to stagnate in the atrial appendages and thrombosis to occur - when the normal heart rhythm is re-established the atrial thrombus may be fragmented and emboli broken off

Answer 77

A reduction in blood flow to a tissue or part of the body caused by constriction or blockage of the blood vessels supplying it

Answer 78

The necrosis / death of part or the whole of an organ that occurs when the artery supplying it has been obstructed

Answer 79

Most of the organs in the human body have only a single artery supplying them (end arterial supply) so they are very susceptible to infarction if this supply is interrupted

Answer 80

Liver Lung Brain

Answer 81

Damage when perfusion is resetablished as damage is oxygen dependent and the only way for oxygen to get to the site is by blood flow When blood flow returns to an area of tissue that has been ischaemic, tissue where transport mechanisms across the cell membrane have been disrupted in particular where calcium transport out of the cell and from organelles such as mitochondria is impaired * This appears to be the trigger for the activation of oxygen-dependent free radical systems that begin the clearing away of dead cells - a hallmark of reperfusion injury * Neutrophil polymorphs and macrophages enter the area and begin to clear away debris and themselves import their own intrinsic oxygen free radicals into the area - resulting in more damage

Answer 82

When whole areas of a limb or a region of the gut have their arterial supply cut off and large areas of mixed tissue die in bulk.

Answer 83

Dry gangrene: * The tissue dies and become mummified and healing occurs above it * So that eventually the dead area drops off - this is a sterile process, and is the common fate of gangrenous toes as a complication of diabetes - Wet gangrene: * Bacterial infection supervenes as a secondary complication; in this case the gangrene spreads proximally and the patient dies from overwhelming sepsis

Answer 84

capillaries are damaged in exposed areas and thus construct severely so that the area they normally supply becomes ischaemic and infarcts

Answer 85

Spasm - decrease NO External compression Steal - diverted blood Hyperviscosity - increased blood viscosity Vasculitis - inflammation of vessel wall

Answer 86

The fatty material which forms deposits in the arteries.

Answer 87

The fatty material which forms deposits in the arteries.

Answer 88

Disease characterised by the formation of atherosclerotic plaques in the intima and degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue, and leading to restriction of the circulation and a risk of thrombosis.

Answer 89

Cerebral infarction - Carotid atheroma - emboli causing transient ischaemic attacks or cerebral infarcts - Myocardial infarction - Aortic aneurysm - rupture causes certain death - Peripheral vascular disease - Gangrene

Answer 90

- central lipid core with fibrous tissue - Collagens and SMC Macrophages and lymphocytes and mast cells - Bordered by foam cells (macrophages that have phagocytksed oxidised lipoproteins with large amounts of cytoplasm) Calcifications in late stages

Answer 91

Hypercholersterolaemia Smoking Hypertension Diabetes Male gender Increasing age

Answer 92

1. Injured endothelial cells: * Enhanced expression of cell adhesion molecules for monocytes * High permeability for macromolecules such as low-density lipoprotein (LDL) * Increased thrombogenicity 2. This allows inflammatory cells and lipids to enter the intimal layer and form plaques 3. In more advanced stages of plaque formation large amounts of macrophages and T cells also accumulate in the plaque tissue 4. Lipid-laden macrophages (foam cells) die, after phagocytosing LDL but eventually die 5. Growth factors, particularly platelet-derived growth factor (PDGF), stimulate the proliferation of intimal smooth muscle cells and the subsequent synthesis of collagen, elastin and mucopolysaccharide by smooth muscle cells 7. This results in the formation of a fibrous cap which encloses the lipid-rich core 8. Growth factors are secreted by; platelets, injured endothelium, macrophages & smooth muscle cells themselves 9. Another important mechanism of plaque growth is haemorrhage - this results from rupture/leakage of micro vessels within the plaque, especially fully developed plaques 10. Large haemorrhage can cause rapid expansion of plaques and may produce clinical symptoms

Answer 93

1. Progressive lumen narrowing due to plaque stenosis. When the stenosis is severe, ischaemic pain may develop even at rest 2. Acute atherothrombotic occlusion leading to infarction 3. Embolisation 4. Ruptured abdominal atherosclerotic aneurysm leading to haemorrhage

Answer 94

- Smoking cessation - Control of blood pressure - Weigh reduction - Low dose aspirin - inhibits the aggregation of platelets, advised for people with clinical evidence of atheromatous disease - Statins - cholesterol reducing drug

Answer 95

A localised permanent dilation of part of the vascular tree

Answer 96

Commonly develop in elderly patients - They may impair blood flow to the lower limbs and contribute to the development of peripheral vascular disease - They may rupture into the retroperitoneal space

Answer 97

Blood is forced through a tear in the aortic intima to create a blood-filled space in the aortic media - This can track back into the pericardial cavity, causing a fatal haemopericardium (blood in pericardiac sac), or can rupture through the aortic adventitia

Answer 98

Occur in the circle of willis, the normal muscular arterial wall is replaced by fibrous tissue - The lesions arise at points of branching, and are more common in young hypertensive patients - Results in a subarachnoid haemorrhage if ruptured

Answer 99

A sudden event with disturbance of CNS functions due to vascular disease

Answer 100

Transient Ischaemic attack Cerebral infarction Intracranial haemorrhage Subarachnoid haemorrhage

Answer 101

A stroke that lasts for less than 24hours and that is associated with complete clinical recovery - Although they show complete resolution, they are risk markers for subsequent cerebral infarction

Answer 102

Most occur within the internal carotid territory, particularly in the distribution of the middle cerebral artery Thrombosis Emboli Head injury Occlusion Reduction in blood flow, oxygen or infection

Answer 103

Occurs 80% of the time in the basal ganglia Other places include; brainstem, cerebellum and cerebral cortex * Most occur in hypertensive adults over 50 * The haemotoma that forms as a result of the haemorrhage acts as a space-occupying lesion resulting in a rapid increase in intracranial pressure & herniation * Most intracerebral haemorrhage occur following the rupture of the lenticulostriate branch of the MIDDLE CEREBRAL ARTERY

Answer 104

Occurs between the arachnoid and pia layers of the cranial meninges - haemorrhage here results in an increase in pressure between the layers which in turn puts pressure on the underlying brain and intracranial vessels * Occurs usually due to the spontaneous rupture of a saccular aneurysm on the circle of willis

Answer 105

A physiological cellular process in which a defined and programmed sequence of intracellular events leads to the removal of a cell WITHOUT the release of products harmful to surrounding cells (programmed cell death)

Answer 106

traumatic cell death which induces inflammation and repair

Answer 107

ensures a continuous renewal of cells - enabling tissues to be more adaptable to environmental demands act to suppress the inflammatory response triggered by necrosis

Answer 108

HIV proteins may activate CD4 on uninfected T-helper lymphocytes inducing apoptosis with resulting immunodepletion & dysfunction

Answer 109

- Growth factors - Extracellular cell matrix - Sex steroids - Some viral proteins

Answer 110

- Growth factor withdrawal - Loss of matrix attachment - Glucocorticoids - Some viruses - Free radicals - Ionising radiation - DNA damage - Ligand-binding at ‘death receptors’

Answer 111

Bcl-2 can inhibit many factors that induce apoptosis Bax forms Bax-Bax dimers which enhance apoptotic stimuli intrinsic pathway responds to stimuli such as growth factors (or their withdrawal) and biochemical stress

Answer 112

p53 is a multifunctional protein which induces cell cycle arrest and initiates DNA damage repair When DNA damage occurs this leads to the stabilisation of the protein product of the p53 gene However if the damage is more difficult to repair then p53 can induce APOPTOSIS via activation of pro-apoptotic members of the Bcl-2 family

Answer 113

Activation of apoptosis characterised by ligand-binding at death receptors on the cell surface tumour necrosis factor receptor (TNFR) gene family e.g.: * TNFR1 * Fas (CD95) Ligand binding at these receptors promotes clustering of receptor molecules on the cell surface, and the initiation of a signal transduction cascade resulting in the activation of CASPASES (cell death enzymes) - This pathway is the mechanism by which the immune system eliminates lymphocytes that would otherwise produce self-antigens

Answer 114

Activation of apoptosis by either the intrinsic or extrinsic pathways results in a cascade of activation of caspases - Caspases are proteases, normally present as inactive pro-caspase molecules - Triggering of apoptosis first leads to the activation of initiator caspases to produce active caspases which cause the degradation of many targets including the cytoskeletal framework and nuclear proteins - Dead cells not phagocytosed fragment into smaller membrane-bound apoptotic bodies - these bodies do not trigger an inflammatory response and are eventually phagocytosed

Answer 115

Commonest form of necrosis * Can occur in most organs * Caused by ischaemia * Following the lack of blood, the cells will retain their outline as their proteins coagulate and metabolic activity ceases

Answer 116

Occurs in the brain because of its lack of any substantial supporting stroma; thus necrotic neural tissue may totally liquefy

Answer 117

a pattern of necrosis in which the dead tissue is structureless almost like “soft cheese” * Whenever caseous necrosis is seen in biopsy TUBERCULOSIS MUST be thought of

Answer 118

Type of necrosis with rotting of the tissues, sometimes as a result of certain bacteria particularly clostridia * The affected tissue appears black because of the deposition of iron sulphide from degraded haemoglobin