Hemodynamics/Thrombosis-embolus/Shock

Question 1

Effusion

Answer 1

Fluid Accumulation in a body cavity
Pleural effusion

Ascites: effusion into peritoneal cavity
Transudate: hemodynamic source
Exudate: With inflammation

Question 2

Edema

Answer 2

Fluid accumulation in interstitial tissue

Question 3

Vascular congestion/Hyperemia

Answer 3

Vascular congestion in the engorgement of blood vessels with blood. Hyperemia is the increase of blood flow to tissue.

Active congestion: Dilation of arteries/arterioles results in increased blood flow (perfusion) of a tissue/organ.–> tissue appears red (mechanism for acute inflammation)

Passive congestion: Impaired venous drainage results in stasis and the accumulation of deoxygenated (bluish/dusky appearance due to accumulation of deoxygenated hemoglobin)

Question 4

Hemmorhage vs. Vascular congestion

Answer 4

Vascular congestion represents blood that is in distended blood vessels. Hemorrhage is a burst blood vessel.

Question 5

Name the key elements (Virchow’s triad) that are involved in thrombosis

Answer 5

• Abnormal blood flow
• Endothelial injury
• Hypercoagulability

Question 6

Formation of embolus formation

Answer 6

An embolus is some material that becomes lodged in a vessel and obstructs it.
It can form from:
thrombus ( Thromboembolus, most common)
artherosclerotic plaque (atheroemboli)
Fat/bone marrow emboli (long bone fractures, 1-3 days after trauma–> acute respiratory insufficiency
Tumor emboli (neoplasm embolization)
Amniotic fluid emboli (occurs during labor or immediately postpartum, fluid and cells from placent enter venous system, rare but often fatal)
Air/gas emboli (air injected intravenously is more likely to be absorbed, whereas intra-arterially is more likely to act as an embolus; also in the bends, nitrogen gas comes out of solution and forms bubbles in the blood.

Question 7

Consequences of embolus formation

Answer 7

Right side: Block blood flow returning to heart and lungs

Left side: Block blood flow to organs, kidneys, toes

Question 8

Shock-general definition

Answer 8

Systemic hypoperfusion of cells and tissues:
-Hypotension
-Increased pulse rate (tachycardia)
Aerobic cellular metabolism switches to anaerobic with increased lactate production

Can lead to ischemia and toxicity.

Question 9

Causes of different types of shock

Answer 9

Cargiogenic: Ischemia (Infarct) Traumatic (Obstruction of outflow, tamponade)—> pump failure

Hypovolemic: Hemmorhage, Fluid loss (burn, “heat stroke”, high volume diarrhea)–> pump failure

Septic: Infection (Bacterial, Fungal)–> vasodilation, peripheral pooling of blood

Question 10

Infarct

Answer 10

Obstructed blood vessel–> lack of oxygen and glucose

Arterial infarct: white infarct, occurs in solid organs with end-arterial circulation (e.g. heart, spleen, and kidney), and where tissue density limits the seepage of blood from adjoining capillary beds into the necrotic area.

Venous infarct: Red infarct, occurs with venous occlusions (e.g. ovary), in loose tissues (eg. lung) where blood can collect in the infarcted zone, in tissues with dual circulations (lung and small intestine, and when flow is re-established to a site of previous arterial occlusion and necrosis.

Irreversible (anatomic lesion), reversible (perturbed physiolgy, transient ischemic event)