Hemodynamics and Shock (not on test)

Question 1

Embolus

Answer 1

A freely movable, intravascular mass that is carried from one anatomic site to another by blood

Question 2

Name the 4 types of emboli

Answer 2

1. Thromboemboli
2. Liquid emboli
3. Gaseous emboli
4. Solid particle emboli

Question 3

Thromboemboli

Answer 3

fragments of thormbi carried by venous or aterial blood. (infected thrombi give rise to septic emboli)

Question 4

Liquid emboli

Answer 4

fat emboli - occur after bone fracture

amniotic fluid emboli - caused by entry of amniotic fluid into the uterine veins during delivery

Question 5

Mural thrombus

Answer 5

• arterial embolus

- most often in patients with Afib

Question 6

Acute bacterial endocarditis

Answer 6

• creates a septic embolus

- Staph aureus is the #1 cause (likes to form abcesses)

Question 7

What is the classic triad for a fat embolism?

Answer 7

After trauma (breakage of long bone- femur, tibia)

1. Difficulty breathing
2. Neurosymptoms (disorientation, coma)
3. Thrombocytopenia (platelets love to adhere to fat globules)

Question 8

Gaseous emboli

Answer 8

air embolism can be produced by injecting air into veins (also with decompression sickness, ie the Bends)

Question 9

Solid particle emboli

Answer 9

Ex.

• cholesterol crystals can detach from atherosclerotic plaques
• tumor cells
• bone marrow emboli

Question 10

Which type of malignancy is notorious for creating tumor emboli?

Answer 10

Renal cell carcinoma (especially renal vein)

Question 11

Which type of emboli is most common?

Answer 11

thromboemboli

classified on basis of vessels through which they are carried in blood

Question 12

Where do venous emboli originate and lodge?

Answer 12

these originate in veins and typically lodge in the pulmonary artery and its branches

Question 13

Where do arterial emboli originate?

Answer 13

• left atrium
• ventricle
• aorta
• major arteries

Question 14

Paradoxical emboli

Answer 14

venous emboli that enter arterial circulation through the foramen ovale or interventricular septal defect

Question 15

Name 3 common places arterial emboli originate from

Answer 15

1. endocardium
2. valve
3. ulcerated atherosclerotic plaques of the aorta

Question 16

Where sized arteries do arterial emboli tend to lodge in?

Answer 16

• Medium-sized arteries
• smaller arteries

*fragment because arterial blood flows fast

Question 17

Which organ is at greatest risk for arterial emboli?

Answer 17

Emboli of cerebral circulation

*typically lodge in the middle cerebral artery and causes infarcts of the basal ganglia

Question 18

Where do arterial emboli typically lodge in the brain?

Answer 18

middle cerebral artery

Question 19

What does an embolism in the middle cerebral artery cause?

Answer 19

infarct of the basal ganglia

Question 20

What organs are vulnerable to arterial emboli?

Answer 20

1. Spleen
2. Kidney
3. Intestine

Question 21

Sharp subcostal pain is associated with what type of emboli?

Answer 21

splenic infact (arterial embolism)

Question 22

Thrombus

Answer 22

transformation of the fluid bood into a solid aggregate encompassing blood cells and fibrin

Question 23

Fibrin

Answer 23

polymerized fibrinogen that forms a meshwork of thin filaments that bind together the cellular elements of the blood

Question 24

Pathologically, how are thrombi classified?

Answer 24

based on location

Question 25

Name the 3 types of thrombi

Answer 25

1. Intramural thrombi 2. Arterial thrombi 3. Venous thrombi

Question 26

Intramural thrombi

Answer 26

attached to the mural endocardium of the heart chambers and commonly are found overlying a MI which may embolize

Question 27

Arterial thrombi

Answer 27

attached to arterial wall and typically cover ulcerated atheromas in an atherosclerotic aorta or the coronary arteries

Question 28

Venous thrombi

Answer 28

-found in dilated veins (varicose veins) (Long-standing venous thrombi are organized by granulation tissue, which may give an impression of inflammation (thrombophlebitis))

Question 29

Name 5 common sites of thrombus formation

Answer 29

1. Varicose veins 2. Heart (valves, over myocaridal infarct) 3. Aorta (atherosclerosis, aneurysm) 4. Coronary arteries 5. Carotid and cerebral arteries

Question 30

Name the two types of thrombi (based on pathologic features)

Answer 30

1. Red thrombi | 2. Layered thrombi

Question 31

Which throbus type is composed of tightly intermixed RBC's and fibrin

Answer 31

Red thrombi

Question 32

Which thrombus type shows distinct layering of cellular elements and fibrin

Answer 32

Layered thrombi

Question 33

Thrombi in small vessels tend to be _______

Answer 33

red thrombi

Question 34

Thrombi in larger arteries and veins, and mural thrombi tend to be _______

Answer 34

layered thrombi

Question 35

"Lines of Zahn"

Answer 35

white layers of fibrin in microscopic thrombi

Question 36

What type of thrombi are lines of Zahn associated with?

Answer 36

layered thrombi

Question 37

Infarct

Answer 37

insufficiency of blood supply of sudden onset that results in an area of ischemic necrosis

Question 38

Most infarctions are caused by? (2)

Answer 38

1. Thrombosis | 2. Emboli

Question 39

How can infarcts be classified pathologically?

Answer 39

Gross appearance - white - red

Question 40

White infarcts

Answer 40

- white or pale - arterial occlusion - solid organs (heart, kidney, etc)

Question 41

In what type of infarction would you expect to see an area of ischemic necrosis caused by the arterial obstruction, typically paler than the surrounding tissue, often rimmed by a thin red zone containing extravasated blood that was destined to reach the ischemic zone from surrounded anastomotic blood vessels

Answer 41

White infarct

Question 42

Red infarct

Answer 42

- venous obstruction - involve intestines (volvulus) or testes (torsion) - Typical of organs with dual blood supply (ex. liver and lungs) *venous circulation interrupted by twisting of the organ

Question 43

What happens as a result of venous compression with red infarct?

Answer 43

- venous congestion - local ischemia - necrosis

Question 44

Which two organs cannot be repaired after infarction?

Answer 44

Heart and Brain

Question 45

What happens to heart tissue after infarction?

Answer 45

damaged cells are replaced with fibrous tisssue, resulting in myocardial fibrosis and scarring

Question 46

What happens to necrotic brain tissue after infarction?

Answer 46

liquefied brain tissue is resorbed, leaving behind cyst fillled with clear fluid that later undergoes gliosis

Question 47

Shock

Answer 47

state of hypoperfusion of tissues with blood

Question 48

Name the 3 mechanisms of shock

Answer 48

1. Cardiogenic shock (heart fails to pump) 2. Hypovolemic shock (loss of fluid/blood) 3. Septic shock (gram negative bacteremia)

Question 49

What is characteristic of all 3 forms of shock?

Answer 49

- collapse of circulation | - disproportion between circulating blood volume and vascular space

Question 50

What does cellular or tissue hypoxia cause?

Answer 50

- shift from aerobic to anaerobic metabolism | - increased lactic acid production (lactic acidosis)

Question 51

How does cardiogenic shock most often take place?

Answer 51

results from pump failure of the heart usually after an area of heart muscle infarcts and dies

Question 52

Causes of hypovolumic shock

Answer 52

- massive hemorrhage - diarrhea - burn - vomiting