Disorders Circulation 8-6-15

Question 1

What type of process is hyperemia? What happens? What is it caused by?

Answer 1

Active Process
-Arterial dilation and increased blood flow
-cuased by sympathetic neurogenic discharge or chemical mediators
-tissues appear “redder”
-ex:
Sites of inflammation
Exercising skeletal muscle

Question 2

What is the difference and similarity between hyperemia and congestion?

Answer 2

Similar: increased intravascular blood volume
Difference:
Hyperemia:Active, tissues Redder
Congestion: Passive, tissues red-blue

Question 3

What is congestion? What is a systemic example?

Answer 3

impaired outflow of venous blood from a tissue

-congestive heart failure

Question 4

What does a congested liver look like macroscopically and microscopically?

Answer 4

Nutmeg

Blood in central vein

Question 5

Hemostasis

Answer 5

• a series of regulated process that
• maintain blood in a fluid clot-free state in normal vessels
• rapidly form a localized hemostatic plug at the site of vascular injury

Question 6

What is hemorrhage?

Answer 6

flow of blood from a ruptured blood vessel

Question 7

What is edema?

Answer 7

Result of movement of fluid from vasculature into interstitial spaces or body cavities

Question 8

What are 5 reasons a patient may have edema?

Answer 8

1. Increased Hydrostatic Pressure
   - systemic: heart failure
   - local: impaired venous return post deep vein thrombosis
2. Decreased colloid osmotic pressure, due to reduced plasma albumin
   - decreased synthesis(liver disease, malnutrition)
   - increased loss (nephrotic syndrome)
3. Lymphatic obstruction
   - neoplasm
4. Increased vascular permeability
   - inflammation
5. Sodium Retention
   - Renal Failure

Question 9

transudate

Answer 9

low protein content, few cells

Question 10

exudate

Answer 10

high, protein content, and may contain some white and red cells

Question 11

Thrombosis

Is this pathologic?

Answer 11

Formation of blood clot within intact vessel

yes

Question 12

What are the three key elements in thrombosis?

Answer 12

• vascular wall
• platelets
• coagulation cascade

Question 13

What are three mechanisms of thrombosis?

Answer 13

1. endothelial injury
   - inflammation, advanced atherosclerosis
2. altered blood flow
   - turbulence (atherosclerotic vessel narrowing) vs. stasis (atrial fibrillation, best rest)
3. hypercoagulable state
   - predisposition to easy clot formation
   - inherited: protein c deficiency
   - acquired: women who smoke and use oral contraceptives; disseminated cancer

Question 14

What do the three key elements in thrombosis: endothelial injury, abnormal blood flow, and hypercoagulability make up? Which is the most important factor?

Answer 14

Virchow’s Triad

• endothelial integrity
• abnormal procoagulants or anticoagulants can tip the balance in favor of thrombosis
• abnormal blood flow can lead to hypercoagulability directly or indirectly through endothelial dysfunction

Question 15

What happens to the lumen of a blood vessel histologically when there is a thrombosis?

Answer 15

filled in pink when it should be white and clear

Question 16

What are the fates of a venous thrombus?

Answer 16

1. resolve
2. embolization to lung
3. organized and recanalized
   - organization incorporated into the way

Question 17

What is an embolism?

Answer 17

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

Question 18

What are 5 different types of emboli?

Answer 18

1. fragments of thrombi (thromboembolism)
2. atherosclerotic(calcium and cholesterol)
3. amniotic fluid
4. air (gas)
5. fat

Question 19

What is an infarct?

Answer 19

Area of ischemic necrosis caused by occlusion of vascular supply to affected tissue

Question 20

What are majority of infarcts associated with?

Answer 20

-thromboembolism and involve arterial occlusions

Question 21

What are the type of infarcts?

Answer 21

1. white (pale) infarct
   -arterial occlusion
   -solid organ with end-arterial circulation
   EX: heart, liver, spleen, kidney
2. red infarct
   - venous occlusions-ovarian torsion
   - tissue with dual circulation-lugn, small intestine
   - loose tissues-lung
   - when flow is reestablished after infarct-s/p angioplasty of arterial obstruction

Question 22

What shape are infarcts in the lung?

Answer 22

• wedge shaped

- blood vessels are dead and so blood is leaving those blood vessels

Question 23

What are 4 factors that influence infarct development?

Answer 23

1. nature of vascular supply
2. rate of development of occlusion
3. vulnerability of tissue to hypoxia
4. oxygen content of blood

Question 24

What does the clinical outcome of thrombosis depend on?

Answer 24

1. degree of occlusion of vessel lumen, collaterals, size of infarct
   - partial occlusion may allow enough blood to flow to vital tissue
   - complete occlusion-usually results in infarct unless there is enough collateral circulation to support oxygen requirements of the tissue

** survival of patient determined by size and location of infarct as well as collateral circulation

Question 25

What is shock characterized by?

Answer 25

systemic hypoperfusion of tissue with resultant

• impaired tissue perfusion
• cellular hypoxia

Question 26

Whis is cardiogenic shock?

Answer 26

-low cardiac output due to myocardial pump failure
EX
-MI
-Ventricular Rupture
-Arrhythmia
-Cardiac Tamponade

Question 27

What is hypovolemic shock?

Answer 27

-low cardiac output due to loss of blood or plasma volume
EX
-hemorrhage
-fluid loss (vomiting, diarrhea, burns, trauma)

Question 28

What is septic shock?

Answer 28

-arteriolar vasodilation and venous blood pooling that stem from systemic immune response to microbial infection