Pathology 1 General 4

dalebira's version from 2018-02-18 18:39

Disorders of circulation

Question Answer
name two conditions which deal with redistribution of blood within a part of the vascular system?hyperemia, ischemia
name two conditions which deal with loss of circulating blood volumehemorrhage, fluid loss.
name two conditions which deal with an accumulation of extravascular fluidtransudate (edema) and exudative (inflammatory)
what is transudate?edema
what is exudate?inflammatory (my ex is a flammer)
name two conditions which deal with the presence of solid masses/abnormal constituents in the blood or BVsthrombus, embolus
what is hyperemia? (general def)inc in vol of blood in tissues
what is active hyperemia? is it physiological or pathological. is it local or generalized? chronic or acute? what does it look like?abnormal accumulation of ARTERIAL BLOOD in an organ or tissue. (active, artery) and it can pathological OR physiological, it's local, and the affected tissues look swollen and bright red
what is passive hyperemia? is it physiological or pathological. is it local or generalized? chronic or acute? what does it look like?accumulation of blood in VEINS AND CAPILLARIES (think "VEINS fill passively"). it is PATHOLOGICAL! it can be local OR generalized. it can be acute OR chronic. the affected area looks dark red or blue and swollen
what would be the cause of an ACUTE, local passive hyperemia?an obstruction of venous drainage-- such as an organ misalignment (telescopy, volvulus, torsion, herniation) or a venous thrombosis or embolism
what would be the cause of a CHRONIC, local passive hyperemia?compression of a vein by a tumor or abscess, etc.
what are the effects of a local passive hyperemia?(1) edema due to inc venous pressure (2) anoxia (lack of O2) which can lead to degeneration and necrosis. consequences depend on the area/organ affected
what are the three possible causes of general passive hyperemia?(1) cardiac failure (valvular, myocardial disorders) (2) impeded venous return (caval thrombosis, hydropericardium) (3) inc pulmonary resistance (hydrothorax, etc)
what are the effects of general passive congestion?(1) reduced output (foreword effect) (2) inc venous pressure (backward effect) (3) LONG TERM EFFECTS IN LUNG/LIVER
what is a forward effect?when there is reduced output (cardiovascular)
what is a backward effect?when there is inc venous pressure
what is the hyperemia of inflammation?acute local active hyperemia
what is the hyperemia of organ misalignment?acute local passive hyperemia
what is the hyperemia caused by a tumor or abscess?chronic local passive hyperemia
what is the hyperemia caused by chronic heart failure?chronic general passive hyperemia
what is ischemia?inadequate blood supply to an organ/tissue (usually arterial)
what are the two main causes of ischemia?heart/circulatory failure, obstruction of an artery
what is the effect of ischemia? (what does it lead to?)leads to INFARCTION! (extent/significance depends on tissues involved)
what is Hemorrhage Per Rhexis?hemorrhage due to the rupture of a blood vessel. (the vessel is rhexed)
what is hemorrhage by diapedesis?blood can squeeze out of the blood vessel very slowly by squeezing through functionally damaged vessel walls. (they would rather die than wait for a vessel to rupture-- they're going out NOW!)
what is petechiae? small (1 - 2 mm) red or purple spot on the skin, caused by a minor hemorrhage (broken capillary blood vessels)
what is ecchymosis?a subcutaneous purpura (extravasation of blood) larger than 1 centimeter or a hematoma
what is purpura?(extravasation of blood) the appearance of red or purple discolorations on the skin that do not blanch on applying pressure. They are caused by bleeding underneath the skin
what is a hematoma? localized collection of blood outside the blood vessels
provided the hemorrhage isn't too large, how does the body maintain volume?peripheral vasoconstriction, use the splenic reserve, and add extra water to the system
how much blood loss is fatal?rapid loss of 1/3 of blood is fatal
what are the 4 causes of non-inflammatory edema?(1) dec plasma oncotic pressure (nutritional if not enough intake, inc loss via renal edema, parasites) (2) inc hydrostatic pressure (usually venous congestion aka cardiac edema) (3) obstruction to lymphatic drainage (organ displacement, parasites, compression) (4) retention of Na+ and H2O (congestive heart failure, nephritis and nephrosis. cause of generalized edema)
generalized edema might be all over, but certain species have certain areas it collects more. where does it go for... dog, cat, sheep/cattle, and horse?Dog= peritoneal cavity, aka ascites. Cat= thoracic cavity aka hydrothorax. Sheep/cattle= sub-mandibular and peritoneum (ascites). Horse= limbs
what is anasarca?generalized edema under the skin (ana's skin looked puffy)
what is ascites?edema in peritoneal cavity
what is hydrocele?edema fluid in scrotal layers
gross appearance of edema?swollen, cool, without pain and redness. it "pits" on pressure applied. pale yellow fluid comes out but does not clot.
microscopic appearance of edema?extracellular space is enlarged. it stains light pink homogenous
etiology (cause) behind exudate vs transudate?exudate= inflammation. transudate= hemodynamic influences
appearance of exudate vs transudate? (fluids)exudate= turbid/opaque/variable (whatever shit is comin out, man). transudate= clear or lightly colored (TRANSparent)
protein content of exudate vs transudate?ex= high. trans=low
specific gravity of exudate vs transudate?ex= 1.018. Trans=1.013
indicate if there is clotting present in exudate vs transudate.ex= +. Trans= -
indicate if there are inflammatory cells in exudate vs transudateex= ++. Trans= -
explain the effect of edema in... lg amount, sm amount, and chronicallyLg= can be FATAL. sm= fluid is absorbed. Chronic= fibrosis and organization
what is a thrombosis?process of formation of thrombus
what is a thrombus?a mass formed from constituents of the blood in blood vessels or heart during LIFE.
what are the causes of a thrombus? (name for the 3 causes?)virchow's triad-- (1) alteration in the vascular endothelium (2) alteration in blood flow (3) alteration in constituents of blood
what are some ways there can be an alteration in the vascular endothelium? what is the direct result of these happening?arteritis, phlebitis, arteriosclerosis, chemicals and anoxic conditions. Platelets deposit to damaged endothelium.
what are some of the types of alterations in blood flow which may lead to thrombus?STASIS and TURBULENCE
define stasis (in terms of alteration of blood flow). where does it usually happen?(reduced flow/ increased stillness) usually in veins following occlusion or post operative recumbence. Stasis increases adhesiveness of platelets, local activation of clotting factors. It also reduces inflow of clotting inhibitors.
define turbulence (in terms of alteration of blood flow). where does it usually happen?(chaotic blood flow) at sites of branching of arteries, in arteriosclerosis, venous valves and congenital heart diseases.
what are two ways the blood composition is altered? (causing hyper-coagulability)(1) hereditary (lack of natural anti-coagulants) (2) acquired (trauma, severe burn, surgery, following parturition, tumor, etc...)
what is a white/pale thrombi? (where is it formed)formed in rapidly moving blood- usually in heart and arteries
what is a red thrombi? (where is it formed)formed in slow moving blood usually in large veins.
what is a mural thrombi?attached to a side of the vessel, not occluding the lumen completely (paint is on the sides of the wall, but not obstructing the walkway)
what is an occlusive thrombi?a thrombi which completely blocks the vessel
Parasitic thrombi in mesenteric arteries of horses usually causes what?severe colic, usually fatal.
Thrombosis of iliac arteries of horses usually causes what?lameness
a thrombi can lead to formation of EDEMAyeah not sure how to word that into a ? without being too vague
what would be an iatrogenic cause of a thrombi?Repeated damage of blood vessels by trauma. Example: inexpert I/V injection
if a cattle gets a thrombi in its vena cava, what do you think caused it?prolly liver abscesses
what are the 4 possible fates of a thrombi?(1) Resolution due to fibrinolysin (2) Organization or recanalization (repair work on the canal, aka BV. restore blood flow basically) (3) Formation of emboli (thrombus breaks easily, and small pieces break off and they start moving through BVs-- this is an emboli) (4) Bacterial invasion of thrombus may give rise to abscess formation and pyemia
compare post-mortem clot to a thrombus in terms of.... colorpost mortem= dark in color. Thrombus= red, pale, or white.
if the obstruction is attached to the wall, is it a thrombus or a embolus, or a post-mortem clot?if it is attached, it is a thrombus!
compare post-mortem clot to a thrombus in terms of.... the surface qualityPost= smooth and shining. Thrombus= dull and rough
compare post-mortem clot to a thrombus in terms of.... attachment to wallPost= NOT attached. Thrombus= ATTACHED.
compare post-mortem clot to a thrombus in terms of.... the shapePost= takes shape of vessel. Thrombus= no shape.
compare post-mortem clot to a thrombus in terms of....presence of laminationsPost= none. Thrombus= laminations of red and white present
compare post-mortem clot to a thrombus in terms of....the arrangement of RBCs, fibrin, and leukocytesPost= those cells are uniformly mixed. Thrombus= not mixed well, vary in diff parts of the thrombus.
compare post-mortem clot to a thrombus in terms of....visibility of fibrinPost= fibrin not observed under low power microscope. Thrombus= you CAN see fibrin under low power microscope (more structure to hold up against the flow of blood)
what is DIC?disseminated intravascular clotting
where does DIC (disseminated intravascular clotting) take place? what is it secondary to?occurs in the microvasculature, and is secondary to platelet activation and/or release of thromboplastin into the circulation
Conditions associated with DIC are varied-- what do they all do though?they initiate coagulation!!!! through thrombin generation. (Simultaneously plasmin activated by kinin and fibrinolytic system degrades coagulation factors and fibrin-- in the whole system, not locally)
the clinical effects of DIC are dependent on what? (what must be balanced? )if thrombin is dominant over plasmin (they should be balanced-- too much plasmin and there is too much bleeding)
what does thrombin do?Thrombin: An enzyme that presides over the conversion of a substance called fibrinogen to fibrin, which promotes blood clotting.
what does plasmin do?the active principle of the fibrinolytic or clot-lysing system, a proteolytic enzyme with a high specificity for fibrin and the particular ability to dissolve formed fibrin clots.
is DIC acute or chronic?can be either!
acute uncontrolled hemorrhage leads to...shock
which species is DIC common in?DOGS
**what is an embolus?Embolus is solid material carried by the blood stream from point of its origin to a distant site within the circulation.
list some types of emboliPieces of thrombus, fat, tumor cells, gas, bacteria and parasites
Effects of emboli? (depends on what, and what is the main effect?)Depends on degree of occlusion, speed of onset and blood supply of organ. It mostly leads to infarction.
embolus of venus side usually lodges where?lungs
embolus of arterial side usually lodges where?systemic capillary bed
what is an infarct?Infarct is an area of necrosis caused by circulatory obstruction of an artery ( in 95% cases) or vein or both. Gross and microscopic lesions of infarct are that of coagulative necrosis.
effects of an infarct?Unless extensive it does not cause pronounced clinical effects, except: Brain- neurological signs. Intestine- colic, gangrene- toxemia.
**what is shock?Shock is a clinical entity caused by inadequate perfusion of tissue.
**what are the three types of causes of shock?cardiogenic, Hypovolemic, Vasculogenic
explain the cardiogenic cause of shock (two types)(1) Reduced cardiac filling (pericardial effusion, cardiac tamponade, compression of heart by pneumothorax, gastric dilatation, torsion etc.) (2) Reduced cardiac emptying (Bradycardia, Valvular disease, reduced cardiac contractility secondary to general anesthesia or cardiomyopathy)
explain the hypovolaemic cause of shock (three types)(1) loss of whole blood (sx, trauma, spleen rupture). (2) loss of plasma (Severe burn, massive tissue trauma, peritonitis, pancreatitis.) (3) Loss of water/electrolytes (Vomiting/diarrhea.)
explain the blood maldistribution cause of shock (three types)(1) Neurogenic (Fright [vasodilation], loss of nervous control of blood vessels [deep general anesthesia, CNS injury].) (2) Endotoxic/sepsis (Overwhelming bacterial infection) (3) Anaphylactic (Massive histamine release)
pathogenesis of shock?Tissue necrosis, hemorrhage and microthrombi. Hyperemia and erosions in the intestinal mucosa, pulmonary edema and hemorrhage
clinical signs of shock?Mental depression- unresponsive to stimuli, weak pulse, subnormal body temperature, anuria, pale mucous membranes and increased respiration