General Pathology, Exam II, Section 3

Why is too much bleeding bad?

Can only replace so much blood, a loss in blood volume is a loss in blood pressure

Why is too much clotting bad?

Block blood vessels and deprive blood flow

What is the process which causes bleeding to stop?

Hemostasis

T/F: Hyperemia is a passive process

False, congestion is a passive process

What allows for hyperemia?

Arteriole dilation

What is a visual sign of hyperemia?

Erythema

What can cause hyperemia?

Inflammation due to exercise (skin and muscle), inflammation of GI tract

T/F: Congestion is an active process

False, hyperemia is an active process

What allows for congestion?

Decreased venous outflow

What is a visual sign of congestion?

Cyanosis

What are some examples of congestion?

Congestive heart failure, DVT

Where are the most common places for DVT to occur?

Leg

How does congestion contribute to edema?

Congestion in venous circulation causes too much hydrostatic pressure and forces fluid out of blood vessels into interstitial space

What is the most common plasma protein?

Albumin

What is the abnormal accumulation of interstitial fluid?

Edema

What are the locations of localized edema?

Lower extremities, peritoneal cavity, pleural cavity

What is localized edema in the peritoneal cavity called?

Ascites

What is localized edema in the pleural cavity called?

Hydrothorax

What is generalized edema in subcutaneous tissues called?

Anasarca

What are the opposing forces of fluid balance?

Hydrostatic pressure and colloid osmotic pressure (oncotic)

Which type of pressure is the pushing force that exerts outward on the vessel wall causing blood to end up interstitially?

Hydrostatic pressure

Which type of pressure is the pulling force maintained by albumin, which causes fluid retention?

Oncotic (colloid) osmotic pressure

What can elevate hydrostatic pressure?

Impaired venous return due to DVT or congestive heart failure

What can lower oncotic pressure?

Too little albumin

What is most likely to cause edema?

Reduced osmotic pressure, increased hydrostatic pressure

How are sodium and water retained?

Osmosis

What are the three characteristics of transudate edema?

Protein poor, increased hydrostatic pressure, non-inflammatory

What are the three characteristics of exudate edema?

Protein rich, caused by osmosis, inflammatory

Which type of edema is pitting edema?

Transudate

What can cause lymphatic obstruction?

Inflammation, tumors, ionizing radiation, inactivity

What is the lymphatic disorder specific to lower extremities due to blockage of inguinal nodes?

Elephantiasis

Why does mastectomy cause lymphadema?

Some lymphatic components removed

What is the extravasatation of blood from vessels?

Hemorrhage

What characterizes hypovolemic shock?

Rapid loss of more than 20% or 1 liter of blood

What is a large accumulation of blood within tissue?

Hematoma

Decreases in what can cause petechiae?

Decreased platelets, decreased vitamin C, decreased vitamin K

What can cause purpura?

Trauma, vasculitis/fragile vessels, AIDS

What type of bruise is caused by high impact, such as a tackle?

Contusion

What type of bruise is characterized by excessive bruising, due to mild trauma?

Ecchymosis

Which proteins cause a bruise to turn from red/blue to green to yellow?

Hemoglobin, bilirubin, hemosiderin

What does an injury to the endothelium expose?

Tissue factor

What does tissue factor generate and initiate?

Thrombin; initiates coagulation cascade

What accomplishes primary clotting?

Platelets

Exposure to what causes platelets to form primary plug?

Sub-endothelial ECM (vWF and collagen)

What are the steps of the coagulation cascade after endothelial cells are damaged?

VWF and collagen, tissue factor, thrombin, fibrinogen, fibrin

What do antiplatelet drugs do and what's an example?

Makes platelet less sticky; aspriin

What do anticoagulants do and whats an example?

Interfere with blood clotting proteins; Coumadin

What are the factors of Virchow's Triad? What do they lead to?

Endothelial injury, abnormal blood flow, hypercoagulability; thrombosis

What can cause abnormal blood flow?

Turbulence or stasis (aneurysm, arrhythmia, immobility, heart valve issues)

What can cause hypercoagulability?

Steroids

What can cause endothelial injury?

Atheroclerosis, hypertension, vasculitis, smoking

What does abnormal blood flow promote?

Endothelial activation

What are primary causes of hypercoagulability? Examples?

Mutation; Factor V, prothrombin

What are secondary causes of hypercoagulability?

Lifestyle or acquired

An increase in ____________ leads to increased ______________ factors

Estrogen; clotting

What are the fates of a thrombus?

Dissolve via tissue plasminogen activator, enlarge, embolism, organize to reform smooth muscle and fibroblasts

What is the best fate of a thrombus?

Dissolve

What is the worst fate of a thrombus?

Embolize

T/F: arterial embolism is most likely to occur

False, venous is most likely

What are the characteristics of a venous thrombus?

Congestion, tenderness, pitting edema

What are the characteristics of an arterial thrombus?

Cell injury, inflammation, infarction

Will a thrombus travel farther if it is venous or arterial? Why?

Venous; low pressure

In which direction do venous thrombi grow?

Anterograde; along with venous flow toward the heart

Where do venous thrombi begin?

Site of stasis

Where are the most common locations of a venous thrombi (DVT)?

Popliteal or femoral

In which direction do arterial thrombi travel?

Retrograde; against arterial blood flow toward the heart

Where do arterial thrombi begin?

Site of injury

Where are the most common locations of an arterial thrombi?

Coronary, cerebral, femoral

What are lines of Zahn associated with?

Clot formation under high pressure (arterial)

What do lines of Zahn on autopsy indicate?

Clot formed when patient was alive

What is widespread thrombosis or coagulopathy?

Disseminated intravascular coagulation

What can cause disseminated intravascular coagulation?

Severe trauma (crushing injuries, sepsis, obstetric complications)

What is unique about disseminated intravascular coagulation?

Ischemia and hemorrhage occur at the same time

What is it called when a detached intravascular mass becomes lodged within a vessel?

Embolism

What can a solid emboli be composed of?

Thrombus, fat, plaque, tumor fragment

What is the most common type of emboli? (Solid, liquid, gas)

Solid

What makes up a liquid thrombus and why is it unique?

Amniotic fluid; undetectable

How can an air gas emboli form?

Injection via hypodermic needle

What disease does a nitrogen gas emboli cause?

Caisson disease

Where do a majority of pulmonary embolisms originate?

DVTs from legs

What are some consequences of a pulmonary embolism?

Cor pulmonale, chest pain, dyspnea, tachypnea, cyanosis, hypoxia

What does a saddle embolism block?

Bifurcation of pulmonary trunk

Where do systemic thromboembolisms occur? What do they arise from?

Arterial system; cardiac thrombi

How do paradoxical embolisms travel?

Venous to arterial

What can cause a paradoxical embolism?

Atrial or ventricular septal defect

What is the death of a tissue due to obstructed blood supply?

Infarction

What is the difference between infarction and infarct?

Process is infarction, lesion is infarct

What type of organs will display a red or hemorrhagic pattern of infarction? Example?

Organs with good collateral blood supply and connective tissue; lung

What type of organs will display a white or pale/anemic pattern of infarction? Examples?

Dense organs with poor collateral blood supply; kidney, spleen, heart

What is defined as inadequate blood supply to tissues resulting in cellular injury, dysfunction, and maybe death?

Shock

Why does cellular hypoxia and dysfunction occur with shock?

Systemic hypoperfusion

What can lead to cardiogenic shock?

Myocardial infarction, arrhythmia, cardiac tamponade

What is hypovolemic shock and what can cause it?

Loss of 20+% of blood; hemorrhage, burns, dehydration

What is the result of septic shock?

Severe systemic inflammation, increased vasodilation and permeability

What can cause neurogenic shock? What results?

CNS trauma, spinal anesthesia; bradycardia, syncope, loss of sympathetic tone

What type of shock is due to an allergic reaction? What happens?

anaphylactic; vasodilation and bronchoconstriction

What occurs during the non-progressive stage of shock?

SNS compensatory mechanisms

What occurs during the progressive stage of shock?

Widespread hypoperfusion; glycolysis shifts to acidosis

What occurs during the irreversible stage of shock?

Widespread membrane and organ failure

What is vasovagal syncope?

parasympathetic fainting