Disorders of Circulation

Question 1

Definition of hyperemia and congestion

Answer 1

Increased intravascular blood volume in tissue, an organ, or part of the body

Question 2

What is hyperemia more specifically?

Answer 2

Dilatation of an artery or arteriole and increased blood flow into the capillaries

Question 3

What causes active hyperemia?

Answer 3

Sympathetic neurogenic discharge or chemical mediators

Question 4

Clinical examples of hyperemia

Answer 4

Acute inflammation of tissue, blushing, body’s need to disippate heat

Question 5

How does hyperemic skin appear?

Answer 5

Red

Question 6

What causes passive hyperemia?

Answer 6

(Congestion)

Impaired venous drainage due to active influence of sympathetic discharge or chemical mediator

Question 7

What is the most common cause of congestion?

Answer 7

Right-sided heart failure

Question 8

Definition of edema

Answer 8

Accumulation of abnormal amounts of fluid in interstitial spaces or body cavities

Question 9

Forces that influence movement of fluid across the capillary wall

Answer 9

Capillary hydrostatic pressure
interstitial hydrostatic pressure
Plasma colloid osmotic pressure
Interstitial colloid osmotic pressure

Question 10

What is the normal physiology of fluid distribution?

Answer 10

All the osmotic forces are near equilibrium and allows for most of the fluid to remain in the vascular compartment and what isn’t is cleared by lymphatics

Question 11

Non-inflammatory edema

Answer 11

Fluid accumulates in the interstitium as a consequence of changes in hydrostatic pressure and colloid osmotic pressure

Question 12

Transudate

Answer 12

Non-inflammatory edema

Question 13

Inflammatory fluid accumulation

Answer 13

Tissue injury alters blood flow and vascular permeability as a result of increased interendothelial space, which is modulated by chemical mediators

Question 14

Exudate

Answer 14

Inflammatory edema

Question 15

Definition of hemorrhage

Answer 15

Flow of blood from a ruptured blood vessel; may flow into tissue, body cavity, or outside the body

Question 16

Mechanism of hemorrhage

Answer 16

Occurs when a large or small blood vessel is disrupted by a mechanical force (trauma) or a pathological process (inflammation, neoplasm)

Question 17

Bleeding diathesis

Answer 17

Abnormal hemostasis that causes a predisposition to bleeding

Question 18

What is the only normal hemorrhage?

Answer 18

Menstruation

Question 19

Hematoma

Answer 19

Solid swelling of clotted blood under the skin

Question 20

Hemothorax

Answer 20

Accumulation of blood in the pleural cavity

Question 21

Hemopericardium

Answer 21

Blood in the pericardial sac of the heart

Question 22

Hemoperitoneum

Answer 22

Blood in the abdominal cavity

Question 23

Hemarthrosis

Answer 23

Blood in the joint cavity

Question 24

Petechiae

Answer 24

Small red or purple spots on the skin caused by ruptured capillaries

Question 25

Purpura

Answer 25

Slightly larger red or purple spots on the skin caused by ruptured vessels

Question 26

Ecchymosis

Answer 26

Discoloration under the skin caused by bleeding into tissues

Question 27

Definition of thrombosis

Answer 27

Blood clot within an uninterrupted vascular system

Question 28

Three mechanisms of thrombosis

Answer 28

Endothelial injury, altered blood flow, hypercoagulable state

Question 29

Examples of endothelial injury as a mechanism of thrombosis

Answer 29

Inflammation, advanced atherosclerosis

Question 30

Examples of altered blood flow as a mechanism of thrombosis

Answer 30

Turbulence vs. stasis: a-fib, bed rest

Question 31

Examples of hypercoagulable state as a mechanism of thrombosis

Answer 31

Predisposition to easy clot formation: protein C deficiency, increased risk by OCPs and smoking

Question 32

Four fates of a thrombus

Answer 32

Propagation Dissolution Embolization Organization & recanalization

Question 33

Define propagation. What are its consequences?

Answer 33

Thrombus enlarges, resulting in increased odd of vascular occlusion or embolization

Question 34

Define dissolution

Answer 34

Activation of the body's fibrinolytic system may lead to rapid shrinkage and even complete dissolution of a newly formed thrombus

Question 35

What occurs over time as the thrombus is being dissolved?

Answer 35

Extensive fibrin polymerization renders the thrombus increasingly resistant to lysis/dissolution.

Question 36

Define embolization (process of thrombosis)

Answer 36

Part or all of the thrombus is dislodged and travels elsewhere in the vasculature

Question 37

Define organization and recanalization

Answer 37

Older thrombi become "organized" with the ingrowth of endothelial cells, smooth muscle cells, and fibroblasts into the thrombus. With time, small vascular channels are formed, reestablishing some flow in the lumen.

Question 38

Definition of an embolism (separate definition)

Answer 38

Intravascular substance (solid, liquid, gas) which is carried by blood from a point of origin to a distant site.

Question 39

Four types of emboli

Answer 39

Thromboembolism Amniotic fluid Gas Fat and marrow embolism

Question 40

Describe amniotic fluid as an embolism process.

Answer 40

Uncommon, serious complication of labor; amniotic fluid enters placental membranes and/or uterine vein rupture

Question 41

Describe gas as an embolism process.

Answer 41

Gas bubbles within circulation obstruct vascular flow, which can develop during medical procedures or from decompression sickness

Question 42

Describe fat and marrow embolisms

Answer 42

Happens s/p soft tissue crush injury or long bone injury where marrow vascular sinusoids release microscopic fat globules into circulation

Question 43

Describe mortality of fat embolism syndrome

Answer 43

Systemic; fatal in 10+% of patients

Question 44

Define infarction

Answer 44

Area of ischemic necrosis within tissue or an organ, produced by occlusion of either its arterial supply or venous drainage.

Question 45

Majority of infarcts are associated with what?

Answer 45

Arterial occlusion by thromboembolism

Question 46

Types of infarct

Answer 46

White (ischemic, arterial) and red (hemorrhagic, venous or arterial)

Question 47

Four factors influencing development of an infarct

Answer 47

- Nature of vascular supply - Rate of development of the occlusion - Vulnerability of tissue to hypoxia - Oxygen content of the blood

Question 48

Clinical outcome of a thrombosis depends on which two factors?

Answer 48

Degree of occlusion and size/location of the blood vessel

Question 49

Definition of shock

Answer 49

Final common pathway for a number of possible events which result in systemic hypoperfusion of tissues

Question 50

What can cause shock?

Answer 50

Diminished cardiac output or reduced effective circulating blood volume

Question 51

Three types of shock

Answer 51

Cardiogenic, hypovolemic, and septic

Question 52

What causes septic shock?

Answer 52

Arteriolar vasodilation and venous blood pooling that stems from systemic immune response to microbial infection