Circulatory Disorders Flashcards
What role does the vascular endothelium play in hemostatic
Anti-thrombotic and pro-fibrinolytic in normal state
Pro-thrombin and anti-fibrinolytic during injury
What are the roles of the vascular endothelium?
Role in homeostasis
Modulate perfusion
Role in inflammation
How does the vascular endothelium modulate perfusion?
NO relaxes and causes vasodilation
Endothelin causes vasoconstriction
What is the role of vascular endothelium in inflammation?
Regulate cellular traffic
Produce-proinflmmatory cytokines
Control angiogenesis and tissue repair
Most body fluid is _________
Intracellular (40%)
Space between tissue compartments where all metabolic products must pass between microcirculation and the cells
Intersitium
What is transcellular fluid
Fluid present in body cavity
Eg cerebrospinal fluid
Aqueous humor of eye
What is the extracellular max trip?
Composed of structural molecules (collagen, reticulin, and elastic fibers) and ground substance (glycoproteins and glycosaminoglycans)
What two forces determine water distribution between plasma and interstitium
Hydrostatic pressure And osmotic (oncotic) pressure
Increased hydrostatic pressure or diminished plasma oncotic pressure can cause ________
Tissue edema
What functions to remove excess volume from the intersitium and will return this fluid back to the circulation
Lymphatic
What are the circulatory disorders ?
Edema Hyperemia and Congestion Hemostatis Hemorrhage Thrombosis and embolism Infarction Shock
Abnormal accumulation of excess extracellular water in interstitial spaces or in body cavities
Edema
What are the two classifications of edema?
Inflammatory -> increase vascular permeability (exudate)
non-inflammatory
What are the 4 main causes of edema?
Increased body hydrostatic pressure
Decreased plasma colloidal osmotic - protein not absorbed/ not produced/ lost
Lymphatic obstruction
Increased vascular permeability
Increased blood hydrostatic pressure can occur in ____________ which causes generalized edema
Right sided congestive heart failure
Eg pulmonary stenosis (narrowing) -> right ventricle cannot maintain normal output to lung -> accumulation -> back up to atrium and venous system =increased hydrostatic pressure
Example of localized increased hydrostatic pressure
Tightly bandaged limb resulting in venous occlusion
Blood trapped in vein -> increased pressure ->
Fluids escapes into intersitium=> edema
How can severe liver disease lead to edema ?
Proteins are not produced -> low albumin levels -> decreased osmotic pressure -> fluids not reabsorbed from interstitium
How can renal disease result in generalized edema?
Glomerular disease-> loss of protein -> loss of oncotic pressure -> decreased absorption-> edema
Intrarenal proteinuria
What type of edema is protein rich
Inflammatory (increased vascular permeability )
“Exudate”
What type of edema is protein poor
Non-inflammatory
Eg. Liver failure
“Transudate”
Gross appearance of edema
Wet Gelatinous and heavy Swollen organs Fluid weeps from cut surface May be yellow
What is the histological appearance of edema?
Clear(non-inflammatory)/pale eosinophilic(inflammatory) Spaces are distended Blood vessels may be filled with RBC Lymphatic are dilated Collagen bundles are separated
Type of edema, where pressure is applied to an areas resulting in a depression/dent
Pitting edema
Interstitial fluid is forced to adjacent areas
Fluids in the thoracic cavity
Hydrothorax
Fluid within the pericardial space
Pericardial effusion
What is mulberry heart disease
Pericardial effusion- Inflammatory edema
Fibrin strands and cloudy appearance
Fluid within the peritoneal cavity
Acites/hydroperitoneum
Generalized edema with profuse accumulation of fluid within subcutaneous tissue?
Anasarca
Type of edema commonly associated with severe GI parasitism and hypoproteinemia
Submandibular edema (bottle jaw)
After prolonged edema, what can occur to tissue?
Become firm and distorted due to increased in fiberous CT
Sudden, diffused and direct- increase in vascular permeability in the lungs
Acute respiratory distress syndrome (ARDS)
Chronic pulmonary edema is most commonly associated with what condition?
Cardiac failure
What is chronic pulmonary edema?
Alveolar walls become thickened->fibrosis
Congestion, micro-hemorrhages-> accumulation of heart failure cells
What is the gross appearance of pulmonary edema ?
Lungs enlarged in thoracic cavity ( can have rib indents)
Surface is wet/moist and heaven
On section of trachea -> froth/fluid in airway
What are heart failure cells and what stain can be used to visualize them?
Cells in alveoli-> macrophages (aka siderophages) containing hemosiderin (iron->metabolic products of heart failure)
Iron (perl’s) stain
What is the difference between hyperemia and congestion?
Hyperemia-> increase of arteiole-mediated engorgement (oxygenated blood)
Congestion-> passive venous engorgement (deoxy blood)
Physiological hyperemia can be due to?
Digestion
Exercise
Dissipate heat
Neurovascular
What are causes of pathological hyperemia?
Inflammation
- > inflammatory mediators cause arteriolar dilation
- > rubor, tumor, calor, pain, loss of function
Condition of obstruction due to twisting of an the stomach
Gastric volvulus (torsion)
Are torsion/volvus due to hyperemia/congestion?
Severe venous congestion –> ischemia and necrosis
_______________ is usually the result of hart failure and associated with edema
Pulmonary congestion
What cells will be present in pulmonary hemosiderosis?
Heart failure cells
Subacute/chronic hepatic congestion is usually the result of ________
Right-sided CHF
In chronic hepatic congestion you can usually see a build up of __________
Fiberous CT
Chronic hepatic congestion is also called?
Nutmeg liver
Nutmeg liver is due to ?
Increased congestion of hepatic vein
Chronically, low grade hypoxia and increased centrolobular hepatocytes leads to ??
Atrophy and necrosis
Escape of blood from the blood vessels
Hemorrhage
Extravasation
What are the causes of hemorrhage?
Trauma
Sepsis/viremeia/bactereimia/toxins
Abdominal neoplasia
Coagulation abnormalities
How does hemorrhage differ from hyperemia and congestion
Hemorrhage - outside vessels wall
Hyperemia and congestion - within the blood vessel
What is the most common cause of hypovolemic shock?
Hemorrhage
Hemopericardium can lead to a fatal ___________
Cardiac tamponade (increased pressure on heart and unable to fill properly)
Due to:
Trauma
Malignant tumor ->hemangiosarcoma rupture (common in dog)
Blood loss due to substantial tear in the vascular wall
Hemorrhage by Rhexis
________________ is a blood filled channel within the aortic wall and can result in rupture and fatal hemorrhage? What species is this usually seen?
Dissecting aneurysm
Pig and turkey-> copper deficiency
Horse -> thoracic injury
Young male racing greyhounds-> coronary and renal arteries
Hemorrhage that is due to small defect in vessel wall or RBC passing through the vessel in case of inflammation or congestion
Hemorrhage by diapedesis
Increased tendency to hemorrhage from usually insignificant injury
Hemorrhagic diathesis
Blood in the thoracic cavity
Hemothorax
Blood in peritoneal cavity
Hemoperitoneum
Blood in a joint space
Hemarthrosis
Coughing up blood or blood-stains sputum from lungs or airways
Hemoptysis
Bleeding from the nose
Epistaxis
What is petechia
Hemorrhage within tissue up to 1-2mm
Found on skin, mucosa, and serosal surfaces
What is ecchymosis?
Larger than petechia (up to 1/ 2 cm
What is agonal hemorrhanges?
Petechiae and ecchymoses associated with terminal hypoxia
What is suffusive hemorrhage?
Larger than ecchymosis and contiguous.
What is Paint-brush hemorrhage? And what tissue is it most commonly found?
A terrible paint job
Mucosal and serosal surfaces.
How are hematoma resolved?
Hemoglobin (dark red/blue) -> enzymatically converted to bilirubin (blue-green)-> hemosiderin (yellow brown)
What is the pathological form of hemostatis in which a clot forms in a vessel
Thrombosis
What is required for hemostasis to occur?
Vascular wall endothelium
Platelets
Coagulation cascade
Describe normal hemostasis
Injury of arteriolar wall -> vasoconstriction -> exposure of glycoproteins Ib rector on platelets to von Willebrand factor->platelet activation -> shape change -> aggregation
Factor 3 thromboplastin exposed -> activate coagulation cascade -> thrombin cleaves fibrinogen to fibrin ->further platelet recruitment ad granule release
Describe formation of a thrombus clot
Polymerized fibrin and platelet aggregated
Tissue plasminogen activator and thrombomodulin activated to limit side of thrombus
Coagulation factors are produced mainly in the ?
Liver
Thrombosis
Formation/presence of solid mass within the CV system
Can result in occlusion of lumen and embolism
What factors can lead to thrombosis formation?
Endothelial injury
Alteration in blood flow (turbulence or stasis)
Hypercoagulability (increase factors or decreased inhibitors)
How can severe renal glomerular disease lead to thrombosis formation?
Protein losing neuropathy -> loss of antithrombin III
Thrombus formation due to strongylus vulgaris infection is called?
Verminous thrombosis
Equine - crainial mesenteric artery common
What are the outcomes of thrombus??
Lysis
Propagation
Organization/recanalization
What is an embolism/embolus ??
Piece of thrombus breaks off from original mass and lodges at a different site
Embolus =mass that breaks off
What embolism can be a complication of long bone fractures?
Fat embolism
Eg. Secondary to CPR efforts -> bone break->bone marrow embolus -> pulmonary artery
Thrombotic meningoencepalitis is often due to what?
Bacterial infection by Histophilus so nice =>vasculitis and thrombosis formation
Pathologic, generalized activation of the blood coagulation system
Disseminated intravascular coagulation (DIC)
Often due to :
- neoplasia injury
- anaphylaxis
Localized area of ischemic necrosis in a tissue or organ caused by occlusion of arterial supply or venous drainage
Infarction
how does a venous infarction differ from arterial infarction
Venous- intensely hemorrhagic as blood backs up into tissue
Arterial- initially hemorrhagic but becomes pale and coagulation necrosis becomes evident
___________ gives rise to systemic hypoperfusion
Shock
Due to reduced CO or reduced effective circulating blood volume
What are the types of shock?
Cardiogenic - decreased CO
Hypovolemic - fluid loss
Blood maldistribution
- anaphylactic
- neurogenic -loss of vascular tone
- septic -host innate immune response to infectious organism
What is the pathogenesis of septic shock?
Usually from endotoxin-producing gram negative bacilli (endotoxin shock) -> bacterial LPS -> Lipid A component -> induce injury and activate WBC -> cytokine release ->vasodilation and pro-thrombotic dathesis (DIC)
