Circulatory Disturbances Flashcards
Coagulation Factors
Plasma proteins produced by the liver
The Circulatory System consists of
blood, a central pump, blood distribution and collection networks, and a system for exchange of nutrient and waste products between blood and extravascular tissue.
Nitric Oxide when released from vascular endothelium has what effect
Relaxation and vasodilation
Water distribution between plasma and interstitium is primarily determined by
Hydrostatic and Osmotic pressure differences between the two compartments
Ground substance of ECM consists of
Glycoproteins (Fibronectin and Laminin), Glycosaminoglycans, Proteoglycans, etc
Possible outcomes to thrombi
Lysis
Propagation
Embolization
Organization/ recanalization
Describe the process of hematoma resolution
Hemoglobin (red/blue) enzymatically converted to bilirubin (blue/green) and eventually into hemosiderin (gold/brown)
Condition
Subacute Hepatic Congestion
______________________
“Nutmeg Liver”
Types of shock
Cardiogenic Shock
Hypovolemic Shock
Blood Maldistribution
Embolus
Any detacehed intravascular mass which is carried by the blood to a site distal to the point of origin
Pathomechanisms of Edema
- Increased blood hydrostatic pressure
- Decreased plasma colloid osmotic pressure
- Lymphatic obstruction
- Increased vascular permeability
Clinical significance of edema
Tissue may become firm and distorted due to an increase in fibrous connective tissue after prolonged edema
Epistaxis
Bleeding from the nose
Plasma accounts for ______% of total water weight
5%
Thrombosis
Formation or presence of a solid mass within the cardiovascular system
Non inflammatory pulmonary edema can be the result of
Left Sided Congestive Heart Failure (CHF)
Clinical significance of hemorrhage is determined by
location and severity
Describe the histologic appearance of edema
- Clear or pale eosinophilic staining
- Dependent on inflammatory vs non-inflammatory
- Spaces distended
- Blood vessels filled with RBC
- Lymphatics dilated
- Collagen bundles separated
Describe what happens during the vasoconstriction step of normal hemostasis
- Brief period of arteriolar vasoconstriction occurs mostly as a result of reflex neurogenic mechanism
- Augmented by local secretions of factors such as endothelin
Example of what circulatory distrubance
Edema
Condition
Ascites or Hydroperitoneum
Suffusive Hemorrhage
Larger than ecchymosis and contiguous.
Intracellular Fluid accounts for _________% of total water weight
40%
Hydrothorax
Fluid in the thoracic cavity
Condition - Fibrin thrombi within glomerular capillaries
Disseminated Intravascular Coagulation (DIC)
Thromboplastin
Promotes blood coagulation
Epistaxis
Thrombomodulin
Has anticoagulent activity
Interstitial fluid accounts for ________% of total water weight
15%
Types of hyperemia
Physiological
Pathological
Ecchymosis
Larger than petechia (up to 1 or 2 cm) as seen in bruise (contusion) or small hematoma
Endothelin released from vascular endothelium has what effect
Vasoconstriction
Classification of hemorrhage
Ecchymosis
Common name for this disease
“Mulberry Heart Disease”
Petechia
Up to 1-2mm in size, especially found on skin, mucosal and serosal surfaces
Total body water is _______% of total body weight
65%
Pathogenesis of Gastric Volvulus (Torsion)
- Twisting of vessels obstructs gastric veins
- Severe venous congestion (acute, local)
- Ischemia (necrosis)
- Loss of endothelial integrity
- Hemorrhage
- Shock
- Death
Describe an arterial Infarct lesion
Initially hemorrhagic but become pale as the are of coagulation necrosis becomes eviden
Example of what circulatory disturbence
Edema
Hemostasis
Arrest bleeding by physiological properties of vasoconstriction and coagulation or by surgical means
Tissue Edema results from what in regards to starling pressures
Increased hydrostatic pressure
Decreased osmotic pressure
Hemorrhagic Diathesis
Increased tendency to hemorrhage from usually insignificant injuries
Submandibular Edema
“Bottle Jaw”
Commonly associated with sever GI parasitism and hypoproteinemia in sheep
Condition
Thrombotic Meningoencephalitis (TME)
Example of what circulatory disturbance?
Hemorrhage
Describe the gross appearance of edema
Wet
Gelatinous and heavy
Swollen organs
Fluid weeps from cut surfaces
May be yellow
What stain is being used? What does it stain?
HE-Stain
Brown pigment staining the cytoplasm of alveolar macrophages
Example of what circulatory disturbance
Edema
Causes of hemorrhage
Trauma
Sepsis, viremia, bacteremia, toxic conditions
Abdominal neoplasia may lead to hemoperitoneum
Coagulation abnormalities
Embolism
Pieces of a thrombus break off from the original mass and sail downstream to lodge at a distant site
Condition
Chronic Hepatic Congestion
_______________________
Nutmeg Liver
What happens at the conclusion of the coagulation cascade
Thrombin converts the soluble plasma protein fibrinogen into fibrin
This condition is usually the result of
Right sided congestive heart failure
Pro-coagulation factors secreted by endothelium
Thromboplastin
Platelet Activation Factor (PAF)
Von Willebrand Factor
Condition
Pericardial Effusion
Describe what happens during the primary hemostasis step of normal hemostasis
- Endothelial injury exposes highly thrombogenic subendothelial ECM allowing platetlets to adhere and be activated
- Activation of platelets results in a dramatic shape change and release of secretory granules lead to further platelet aggregation to form the primary hemostatic plug
- Secreted products recruit additional platelets
Difference betwen hemorrhage and hyperemia/congestion
Hemorrhage the blood is outside the vessel wall
Hyperemia/Congestion the blood is within the blood vessels
In which direction does hydrostatic pressure move fluid?
Moves fluid out of vasculature
Cardinal signs of inflammation
Reddening - Rubor
Edema - Tumor
Heat - Calor
Pain
Loss of Function
Describe the basic mechanism of normal hemostasis
- Vasoconstriction
- Primary hemostasis
- Secondary hemostasis
- Thrombus and antithrombotic events
Prostacylin
Causes vasodilation, inhibits platelet aggregation
Pathogenesis
Twisting of vessels obstructs gastric veins → severe venous congestion (acute,local, congestion) → ischemia (necrosis → loss of endothelial integrity → hemorrhage → shock → death
Hemoperitoneum
Blood in the peritoneal cavity
Causes of physical hyperemia
- Digestion
- Exercise
- Dissipation of heat
- Neurovascular - facial hyperemia (blushing)
Hemorrhage
Escape of blood from the blood vessels
Example of what circulatory disturbance?
Hemorrhage
Condition
Gastric Volvulus (Torsion)
Secretory granules secreted during primary hemostasis
ADP and TXA2
Agonal Hemorrhages
Petechiae and ecchymoses associated with terminal hypoxia
Increased blood hydrostatic pressure can be the result of
Generalized - Right sided CHF
Localized - Tightly bandaged limb resulting in venous occlusion
Condition
Pulmonary Edema
Example of what circulatory disturbance
Edema
________________
Inflammatory Edema
Classification of hemorrhage
Suffusive Hemorrhage
Extracellular Matrix is composed of
Structural molecules
Ground substance
Etiology
Histophilus somni infection
Key players in the regulation of homeostasis, as the balance between anti and prothombotic activities of endothelium determines whether thrombus formation propagation or dissolution occurs
Endothelial Cells
This condition is usually the result of what?
Heart failure and associated edema
Pathogenesis of septic shock
- Endotoxin - producing gram negative bacilli
- LPS and other microbial substances induce injury and activation of the vascular endothelium
- Stimulate WBCs to release cytokines
- Vasodilation and prothrombotic diathesis
Chronic pulmonary edema is most commonly associated with
Cardiac failure
Cardiogenic Shock
Failure of the heart to maintain normal cardiac output
Interstitium
Space between tissue compartments - microcirculation and the cells. Medium through which all metabolic products must pass between the micocirculation and the cells
Describe what happens in the thrombus and antithrombotic event step of normal hemostasis
- Polymerized fibrin and platelet aggregates form a solid permanent plug to prevent any additional hemorrhage
- Counter regulatory mechanisms and thrombomodulin are set into motion to limit the hemostatic plug to the site of injury
Classification of hemorrhage
Petechia
Acute Respiratory Distress Syndrome (ARDS)
Sudden, diffuse and direct - increase in vascular permeability.
High fatality rate
Pneumonia if animal survives
Tissue Plasminogen Activator (tPA)
Regulates fibrinolysis
Platelet Activating Factor (PAF)
Causes activation of platelets and neutrophils
Anti-coagulation factors secreted by endothelium
Prostacylin
Nitric Oxide
Tissue Plasminogen Activator (tPA)
Thrombomodulin
In which direction does osmotic pressure (of plasma protein) move fluid?
Moves fluid into the vasculature
Example of what circulatory disturbance?
Congestion
Role of vascular endothelium in hemostasis
- Anti-thrombotic and pro-fibrinolytic in normal state
- Pro-thrombotic and anti-fibrinolytic during injury
Hemorrhage by Rhexis
Due to a substantial rent or tear in the vascular wall (or heart)
Disseminated Intravascular Coagulation (DIC)
Systemic reaction in which there is generalized activation of the blood coagulation system
Anasarca
Generalized edema with profuse accumulation of fluid within the subcutaneous tissue
Hemoptysis
Example of what kind of embolism
Fat Embolism
This condition is caused by
Copper deficiency
Describe the fluid in inflammatory edema
Protein rich ( > 30g/L)
Specific Gravity ( > 1.025)
Total nucleated cells ( < 7x109L)
Less than 7000 cells per uL
Pulmonary congestion is usually the result of
Heart failure - associated with edema
Example of what circulatory disturbance?
Congestion
Infarction
Localized area of ischemic necrosis in a tissue or organ caused by occlusion of either the arterial supply or the venous drainage
Example of what circulatory disturbance
Edema
Most water leakage occurs in capillaries or post-capillary venues because they have
Semi-permeable membrane wall that allows water to move more freely than proteins
Role of vascular endothelium in inflammation
- Regulate the traffic of inflammatory cells
- Produce pro-inflammatory cytokines
- Control angiogenesis and tissue repair
Starling Equation
Illustrates the role of hydrostatic and osmotic forces in the movement of fluid across capillary membranes
Nutmeg Liver
Appearance of the parenchyma with animal suffering from chronic hepatic congestion
Example of what circulatory disturbance
Infarction
_____________________
Arterial Infarct
Hypovolemic Shock
Fluid loss due to hemorrhage, vomiting, diarrhea
Clinical significance of edema dependent on
Extent
Location
Duration
Verminous Thrombosis
Thrombus formation in the cranial mesenteric artery of horses with Strongylus vulgaris infection
Fat Embolsim can be the result of
long bone fractures
Endothelin
Potent endothelium - derived vasoconstrictor
Describe what happens during the secondary hemostasis step of normal hemostasis
- Tissue factor is exposed at the site of injury
- Thrombin cleaves circulating fibrinogen into soluble fibrin creating a fibrin meshwork deposition
- Thrombin also induces further platelet recruitment and granule release
Example of what circulatory disturbance
Thrombosis
Hemopericardium leads to
Fatal Cardiac tamponade
Pathogenesis of thrombosis
- Endothelial injury
- Alteration in blood flow - turbulence or stasis
- Hypercoagulability
- Increase coagulation factors
- Decrease coagulation inhibitors
Example of what circulatory disturbance
Congestion
Interstitium is composed of
Extracellular Matrix (ECM)
Supporting Cells
Example of what circulatory disturbance
Congestion
_________________
Pulmonary congestion
Von Willebrand Factor
Promotes platelet adhesion and activation of blood coagulation
Condition
Hydrothorax
Pathogenesis of Nutmeg Liver
- Low grade chronic hypoxia
- Increased pressure of centralobular hepatocytes
- Atrophy
- Necrosis
Homeostasis
A tendency to stability in the normal body states
Heart Failure Cells
Hemosiderin - laden macrophages
Characteristic of left sided CHF
What is the stain being used? What does it stain?
Iron (Perl’s) Stain
Hemosiderin-laden macrophages - “Heart Failure Cells”
Ascites (Hydroperitoneum)
Fluid (transudate) within the peritoneal cavity
Thrombus
Aggregate of platelets, fibrin and entrapped blood cells. Can result in occlusion of the vascular lumen and embolism. It is adhered to the vascular wall as opposite to blood clot
Shock - Cardiovascular Collapse
Final common pathway for a number of potentially lethal clinical events. Gives rise to systemic hypoperfusion.
Transcellular Fluid accounts for _______% of total water weight
5%
Edema
Abnormal accumulation of excess extracellular water in interstitial spaces or in body cavities
_____________________
Fluid is outside both vascular fluid compartment and cellular fluid compartment
Edema can be classified as
Inflammatory
Non-Inflammatory
Decreased plasma colloid osmotic pressure can be the result of
- Proteins not absorbed from diet
- Proteins not produced
- Protein loss
Hyperemia
Increase of arteriole mediated engorgement of the vascular bed - blood is oxygenated
Classification of hemorrhage
Paintbrush hemorrhage
Pathological form of hemostasis is
Thrombosis
Non-inflammatory Edema
Edema of CHF or liver failure, etc - refers to as a transudate
Hemoptysis
Coughing up of blood or blood-stained sputum from the lungs or airways
Classification of hemorrhage
Agonal Hemorrhages
Example of what circulatory disturbance
Thrombus
_______________________
Mural thrombus
Condition
Intestinal volvulus
Hemostasis
Arrest bleeding by physiological or surgical means
T/F: There are infectious causes of thromosis/ thromboembolism
True
______________________
Bacterial valvular endocarditis
Thrombotic Meningioencephalitis
Example of circulatory disturbence
Edema
___________________
Pitting Edema
Example of what circulatory disturbance
Congestion
Venous Infarcts
Intensely hemorrhagic as blood backs up into the affected tissue behind the obstruction
End results of shock
Hypotension
Impaired tissue perfusion
Cellular hypoxia
DIC and multi-organ system failure
Condition
Hepatic Congestion
Example of what circulatory distrubance
Thrombosis
_______________________
Verminous thrombosis
Condition
Submandibular edema
_______________________
“Bottle Jaw”
Chronic pulmonary edema causes
Alveolar walls to become thickened - fibrosis
Congestion, micro-hemorrhages and accumulation of heart failure cells
Condition
Pulmonary Edema
Thrombosis
Clot (thrombus) forms within a vessel which is not injured or only mildly injured
Histological appearance of what circulatory disorder
Edema
Pitting Edema
Pressure is applied to an area of edema a depression or dent results as excessive intersitial fluid is forced to adjacent areas
Example of what circulatory disturbance
Thrombosis
___________________
Saddle Thrombosis
Pericardial Effusion
“Mulberry Heart Disease”
Inflammatory edema
Fibrin strands and cloudy appearance of pericardial fluid
Inflammatory pulmonary edema can be the result of
Damage to pulmonary capillary endothelium
Shock caused by blood maldistribution can be due to
Anaphylactic - Type I Hypersensitivity
Neurogenic
Septic
Hemarthrosis
Blood within a joint space
Describe the fluid in non-inflammatory edema
“Protein Poor”
Low protein content ( <30g/L)
Low specific gravity ( < 1.025)
Low cellularity ( < 1.5x109L)
Less than 1500 cells per uL
Congestion
Passive venous engorgement - blood is not oxygenated
Tissue Factor - Factor III-Thromboplastin
Membrane bound procoagulant glycoprotein synthesized by endothelium. Acts in conjunction with Factor VII as the major in vivo pathway to activate the coagulation cascade, eventually culminating in thrombin
Paint Brush Hemorrhage
Looks like if red paint was hastily applied with a paint brush - most common on mucosal and serosal surfaces
Condition
Colonic Torsion
Pathological hyperemia is usually caused by
Inflammation
Subactue to chronic hepatic congestion is usually the result of
Right Sided Heart Failure
Hemorrhage by Diapedesis
Hemorrhage due to a small defect in the vessel wall or RBCs passing through the vessel wall in cases of inflammation or congestion
Hemothorax
Blood in the thoracic cavity
Gingivitis and blood shot eyes are an example of what circulatory disturbance
Hyperemia
Iron (Perl’s) Stain
Highlights hemosiderin - laden macrophages within alveoli
_____________________
Stains blue
Example of what circulatory disturbance
Congestion and Edema
Components necessary for normal hemostasis or thrombosis
Vascular wall
Platelets
Coagulation cascade
Substances released from vascular endothelium that modulate perfusion
NO
Endothelin
Nitric Oxide
Causes vasodilation, inhibits platelet adhesion and aggregation
Example of what circulatory disturbance?
Thrombosis
Example of what circulatory disturbance
Infarction
Structural molecules of the ECM include
Collagen, Reticulin and Elastic Fibers
Inflammatory Edema
Increased vascular permeability - refers to as an exudate
Condition
Dissecting aneurysm
Coagulation Cascade
Amplifying series of enzymatic conversions; each step proteolytically cleaves an inactive proenzyme into an activated enzyme, culminating in thrombin formation
