L5 Disorders of Circulation

Question 1

Hyperemia and congestion both refer to what process?

Answer 1

Increased intravascular blood volume (in a tissue, organ, or body part)

Question 2

Hyperemia is an ___ (active/passive) process. What are the two features of this process?

Answer 2

Active; arteriolar dilatation and increased blood flow

Question 3

What are two examples of hyperemia?

Answer 3

1. Sites of inflammation

2. Exercising skeletal muscle

Question 4

Congestion is an ___ (active/passive) process. What is the main feature of this process?

Answer 4

Passive; impaired outflow of venous blood from a tissue

Question 5

Describe the color of the tissue in hyperemia and congestion.

Answer 5

Hyperemia: redder
Congestion: red-blue

Question 6

What is a clinical example of congestion?

Answer 6

Congestive heart failure

Question 7

Describe the appearance of a liver that is being affected by congestion.

Answer 7

Nutmeg appearance (redder), sinusoids are congested

Question 8

What can happen with chronic hepatocyte congestion?

Answer 8

Ischemia (injury to hepatocytes, which are being squished by blood-filled sinusoids); leads to coagulative necrosis

Question 9

What is hemostasis?

Answer 9

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

Question 10

What is a hemorrhage?

Answer 10

Flow of blood from a ruptured blood vessel into tissue, body cavity, or outside body

Question 11

What are 5 potential causes of edema?

Answer 11

1. Increased hydrostatic pressure
2. Decreased colloid osmotic pressure (reduced plasma albumin)
3. Lymphatic obstruction
4. Increased vascular permeability (inflammation)
5. Sodium retention

Question 12

How does heart failure lead to edema?

Answer 12

1. Increased capillary hydrostatic pressure

2. Decreased renal blood flow –> activated RAA system –> retain sodium/water –> increase blood volume

Question 13

How do malnutrition, decreased hepatic synthesis, and nephrotic syndrome lead to edema?

Answer 13

Decreased plasma albumin leads to decreased plasma oncotic pressure, fluid flows out of vessels to equilibrate

Question 14

What is transudate?

Answer 14

Edema with low protein content and few cells; caused by increased hydrostatic pressure and/or decreased colloid osmotic pressure

Question 15

What is exudate?

Answer 15

Edema with high protein content and some cells; caused by injury to the vasculature

Question 16

What is thrombosis?

Answer 16

Formation of blood clot (thrombus) within an intact vessel

Question 17

What are the three key elements to normal hemostasis?

Answer 17

1. Intact vascular wall
2. Sufficient platelets
3. Coagulation cascade in check

Question 18

What are the three major mechanisms of thrombosis?

Answer 18

1. Endothelial injury
2. Altered blood flow
3. Hypercoagulable state

Question 19

What are the three components of Virchow’s triad in thrombosis? What is the most important factor?

Answer 19

1. Endothelial injury (most important)
2. Abnormal blood flow
3. Hypercoagulability

Question 20

What are the three potential fates of a venous thrombus?

Answer 20

1. Propagate (toward heart)
2. Embolize (break off)
3. Organize (develop an ECM, incorporate into wall)

Question 21

What is organization?

Answer 21

Ingrowth of endothelial cells, smooth muscle cells, and fibroblasts into a thrombus

Question 22

What is recanalization?

Answer 22

Capillary channels forming within the length of a thrombus

Question 23

What is an embolism?

Answer 23

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

Question 24

What are the 5 types of emboli?

Answer 24

1. Fragments of thrombi (thrombembolism)
2. Atherosclerotic
3. Amniotic fluid
4. Air (gas)
5. Fat

Question 25

What is an infarction?

Answer 25

Area of ischemic necrosis caused by occlusion of vascular supply to affected tissue (leads to coagulative necrosis, unless in the brain = liquefactive)

Question 26

What are the two major types of infarcts?

Answer 26

1. White (pale) | 2. Red

Question 27

Define a white infarction.

Answer 27

Arterial occlusions occurring in a solid organ with end-arterial circulation

Question 28

What are the three major organs that experience white infarction?

Answer 28

1. Heart 2. Spleen 3. Kidney

Question 29

Define a red infarction.

Answer 29

1. Tissues with dual circulations 2. Venous occlusions 3. Loose tissues 4. Re-establishment of flow

Question 30

What are the two major organs that experience red infarction as a result of dual blood supply?

Answer 30

Lung, SI

Question 31

What are the 4 factors that influence infarction development?

Answer 31

1. Nature of vascular supply (end vs. dual) 2. Rate of development of occlusion (fast vs. slow) 3. Vulnerability of tissue to hypoxia (brain/heart vs. other tissue) 4. Oxygen content of blood (high vs. low)

Question 32

What is shock?

Answer 32

Systemic hypoperfusion of tissues with resultant impaired tissue perfusion and cellular hypoxia

Question 33

What are the three major types of shock?

Answer 33

1. Cardiogenic 2. Hypovolemic 3. Septic

Question 34

What happens in cardiogenic shock?

Answer 34

Low Cardiac Output due to myocardial pump failure (MI, ventricular rupture, arrhythmia, cardiac tamponade)

Question 35

What happens in hypovolemic shock?

Answer 35

Low cardiac output due to abrupt/dramatic loss of plasma volume or blood volume (hemorrhage, fluid loss - vomiting, diarrhea, burns, trauma)

Question 36

What happens in septic shock?

Answer 36

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