Disorders of Circulation

Question 1

Define hyperemia and congestion?

Answer 1

both refer to increased intravascular volume in a tissue, an organ, or body part

Question 2

What kind of process is hyperemia, and how does it occur?

Answer 2

Hyperemia is an active process, and is caused by arteriolar dilation and increased blood flow. This is caused by sympathetic neurogenic discharge or chemical mediators

Question 3

What will be the appearance of tissues with hyperemia?

Answer 3

rubor (red) color

Question 4

What are two exmaples of hyperemia?

Answer 4

sites of inflammation

exercising skeletal muscle

Question 5

What kind of process is congestion, and how does it occur?

Answer 5

Congestion is a passive process, caused by impaired outflow of venous blood from a tissue. Can be systemic or local, acute or chronic

Question 6

What will be the appearance of tissues with congestion?

Answer 6

red-blue color

Question 7

What is a clinical example of congestion?

Answer 7

congestive heart failure resulting in hepatic congestion

Question 8

What are the characteristics of a necrotic cell in chronic hepatocyte congestion?

Answer 8

loss of nuclei
cytoplasm is ragged (no distinct outline of cells)
coagulative necrosis
pyknosis

Question 9

define hemostasis

Answer 9

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

Question 10

Define hemorrhage

Answer 10

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

Question 11

What can lead to hemorrhage?

Answer 11

trauma

pathological process (congestion, inflammation, neoplastic erosion of vessel)

abnormal hemostasis

Question 12

Define edema

Answer 12

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

Question 13

What pathological processes can lead to edema?

Answer 13

increased hydrostatic pressure

decreased colloid osmotic pressure due to reduced albumin

lymphatic obstruction

increased vascular permeability

sodium retention

Question 14

What can result from edema due to increased hydrostatic pressure?

Answer 14

systemic: heart failure

Local: impaired venous return post deep venous thrombosis

Question 15

How can reduced colloid osmotic pressure occur?

Answer 15

decreased synthesis of albumin (liver disease, malnutrition)

increased loss of albumin (nephrotic syndrome)

Question 16

What can a lymphatic obstruction be caused by?

Answer 16

neoplasm

Question 17

what can cause increased vascular permeability?

Answer 17

inflammation

Question 18

What can cause sodium retention?

Answer 18

renal failure

Question 19

What are the three main pathways leading to edema?

Answer 19

heart failure leading to increased capillary hydrostatic pressure and edema

decreased renal blood flow which activates the renin-angiotensis-aldosterone system resulting in retention of Na and H20 which will increase blood volume and lead to edema

malnutrition, decreased hepatic synthesis, or nephrotic syndrome can result in decreased plasma albumin which will lead to edema

Question 20

what is transudate normally due to?

Answer 20

increased hydrostatic pressure and/or decreased colloid osmotic pressure

Question 21

What is exudate normally do to?

Answer 21

inflammation

Question 22

Define Thrombosis

Answer 22

formation of a blood clot within an intact vessel

Question 23

Is a thrombosis normal or pathological?

Answer 23

thrombosis is pathological

Question 24

What are three key elements to maintain normal hemostasis?

Answer 24

vascular wall (esp endothelium) must be intact

platelets

coagulation cascade

Question 25

What are three mechanisms that will lead to thrombosis (Virchow's triad)?

Answer 25

endothelial injury (inflammation, atherosclerosis) altered blood flow (turbulence, stasis) hypercoagulable state (predisposed - inherited protein C deficiency, smoking/oral contraceptives, cancer, obesity)

Question 26

What is the most important factor in Virchow's triad of thrombosis?

Answer 26

endothelial integrity

Question 27

Define embolism

Answer 27

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

Question 28

What are some different types of emboli?

Answer 28

fragments of thrombi (thromboembolism) atherosclerotic amniotic fluid air (gas) fat (from bone marrow)

Question 29

When will a bone marrow/fat embolus develop?

Answer 29

in patients with severe skeletal injuries fat embolism syndrome is systemic and presents with pulmonary insufficiency, neuro symptoms, anemia, thrombocytopenia, petechial rash

Question 30

When will an amniotic fluid emboli develop?

Answer 30

uncommon complication of labor, mortality rate 80% presents with nuro deficits, dyspnea, cyanosis, shock

Question 31

Define infarct

Answer 31

area of ischemic necrosis (coagulative) caused by occlusion of vascular supply to the affected tissue

Question 32

What are the majority of infarcts associated with?

Answer 32

thromboembolism and involve arterial occlusions

Question 33

What are the two types of infarcts?

Answer 33

White (pale) and Red

Question 34

Describe white infarcts

Answer 34

due to arterial occlusions of solid organs with end-arterial circulation (eg heart, liver, spleen, kidney)

Question 35

What are red infarcts due to

Answer 35

venous occlusions tissues with dual circulations loose tissues flow re-established after infacrction

Question 36

What are some factors that influence infarct development?

Answer 36

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

Question 37

What is the clinical outcome of thrombosis?

Answer 37

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

Question 38

define shock

Answer 38

characterized by profound systemic hypoperfusion of tissues with resultant impaired tissue perfusion and cellular hypoxia

Question 39

What are the three major types of shock?

Answer 39

cardiogenic hypovolemic septic

Question 40

Describe cardiogenic shock

Answer 40

low cardiac output due to myocardial pump failure - MI - ventricular rupture - arrhytmia - cardiac tamponade

Question 41

describe hypovolemic shock

Answer 41

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

Question 42

describe septic shock

Answer 42

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