Quiz 2 part 1

Question 0

Define Thromboemboli

Answer 0

Fragments of thrombi carried by venous or arterial blood

Question 1

What type of embolism accounts for most of the emboli in clinical practice

Answer 1

Thromboemboli

Question 2

How are thromboemboli classified?

Answer 2

Classified on the basis of the vessels through which they are carried

Question 3

2 examples of liquid emboli

Answer 3

1. Fat emboli that occur after bone fracture

2. Amniotic fluid emboli caused by the entry of amniotic fluid into the uterine veins during delivery

Question 4

2 ways an air embolism can be produced

Answer 4

1. injecting air into the veins

2. Air that is liberated under pressure, as in decompression sickness is yet another form

Question 5

Describe a few examples of solid particle emboli

Answer 5

1. Cholesterol crystals can detach from atherosclerotic plaques as well as from tumor cells, bone marrow emboli or bullets

Question 6

Describe the venous emboli. What can they cause?

Answer 6

Originate in veins and typically lodge in the pulmonary artery and its pulmonary branches causing pulmonary embolism

Question 7

What is a paradoxical emboli

Answer 7

Venous emboli that reach the arterial circulation through the foramen ovale or an interventricular septal defect that can cause symptoms similar to those of arterial emboli

Question 8

Where do arterial emboli originate? Describe arterial emboli in general

Answer 8

Originate in the left atrium or ventricle, aorta, and major arteries
- Carried by arterial blood, important cause of infarction resulting from occlusion of peripheral arteries

Question 9

What is a true bone marrow emboli? When do you normally see them?

Answer 9

One complete with hematopoietic cells and fat are often seen in the lungs at autopsy.
- Usually encountered after cardiac resuscitation in which fractures of the bones of the sternum, thorax and ribs are common. No symptoms related to this event.

Question 10

What are the 3 types of shock?

Answer 10

1. Cardiogenic Shock
2. Hypovolemic shock
3. Septic Shock

Question 11

Describe Cardiogenic shock

Answer 11

Results from pump failure of the heart

• Most often secondary to an infarction that destroys a large part of the functioning myocardium
• THe loss of contractile elements decreases the ability of the heart to pump blood, leading to arrythmia

Question 12

Describe Hypovolemic shock

Answer 12

Results from a loss of circulatory volume, attributed to massive hemorrhage or to water loss related to massive burn, vomiting, or diarrhea

Question 13

Describe Septic Shock

Answer 13

Severe G- endotoxin bacteremia –> shock resulting from the spread of bacteria from a severe localized infection into the bloodstream (ie. abscesses, pneumonia, or peritonitis)

Question 14

T or F, Septic shock only occurs with endotoxin-producing G- bacteria

Answer 14

False, It can also occur with G+ and fungal infections

Question 16

What is the most common cause of death in ICU’s

Answer 16

Septic shock (>100,000/year)

Question 17

Describe the components of a thrombus

Answer 17

Transformation of the fluid blood into a solid aggregate encompassing:

• blood cells
• fibrin (thin filaments binding together cellular elements of blood)

Question 18

What is fibrin made up of?

Answer 18

Fibrin is polymerized fibrinogen and forms a meshwork of thin filaments that bind together the cellular elements of the blood forming a thrombus or clot

Question 19

Describe the first step of the fate of a thromus

Answer 19

Initially, the attachment of the larger thrombi is mediated by the actions of adhesion molecules such as fibrin

Question 20

Describe the organization process of thrombi

Answer 20

With time after attachment, the thrombus stimulates the in growth of inflammatory cells and vessels, producing granulation tissue. This tissue provides firmer anchorage.

Question 21

What do the inflammatory cells of the granulation tissue do to a thrombus during or immediately after the “organization” process

Answer 21

The inflammatory cells of the granulation tissue dissolve the thrombus, while the thrombus is replaced by collagen from the granulation tissue.

Question 22

What are the 4 fates of the thrombi

Answer 22

1. Lysis and resolution
2. Organization
3. Recanalization (Occlusive thrombi recanalizes)
4. Embolism (if cannot attach it breaks off)

Question 23

What is a heart failure cell

Answer 23

Are alveolar “hemosiderin-laden” macrophages.

- These MO take up disintegrated RBC’s that were let into the alveoli of the lungs as a result of Hyperemia.

Question 24

What is the component of the heart failure cells

Answer 24

RBCs found in alveoli
Hemoglobin of RBC (Hemosiderin)
- this accumulates in lysosomes of these macrophages

Question 25

Where do venous emboli originate? where do they end up?

Answer 25

in veins and typically lodge in the pulmonary artery and its pulmonary branches causing pulmonary embolism

Question 26

Where does a pulmonary embolism originate?

Answer 26

typically originate in the deep veins of the lower extremities and are carried by venous blood to the vena cava, through the right atrium and ventricle and then into the pulmonary artery

Question 27

Define saddle embolus

Answer 27

An embolus that straddles the branching of an artery blocking both branches (specifically pulmonary artery from heart)

Question 28

How lethal are saddle emboli and why?

Answer 28

Often lethal because they prevent the entry of blood into the lungs and cause acute anoxia.

Question 29

What two other things may block pulmonary circulation other than pulmonary embolism

Answer 29

Amniotic fluid and Air emboli

Question 30

What is the end result of a paradoxical emboli?

Answer 30

Can cause symptoms similar to those of arterial emboli which are common causes of ischemia in various organs (including infarction)

Question 31

Where do arterial emboli originate?

Answer 31

Most originate from the endocardium or from valvular thrombi

Question 32

Arterial emboli usually flow in the blood stream in what shape? Why?

Answer 32

They are fragmented inside the vessels because blood flows fast and disrupts them - They tend to lodge in medium-sized and smaller arteries

Question 33

Which is the greatest risk of arterial emboli

Answer 33

The greatest risk is associated with emboli of the cerebral circulation, which typically lodge in the middle cerebral artery and causes infarcts of the basal ganglia

Question 34

Describe a fat embolism

Answer 34

Describes the release of emboli of fatty marrow into damaged blood vessels following trauma to fat-containing tissue, particularly with bone fractures.

Question 35

How quickly does fat embolism syndrome appear

Answer 35

1-3 days after the injury

Question 36

What characterizes fat embolism syndrome in its most severe form? What other things may characterize it?

Answer 36

``` Respiratory failure (ARDS) - It is also characterized by mental changes, thrombocytopenia, and widespread petechiae. ```

Question 37

What organs are generally involved in fat embolism syndrome

Answer 37

Lungs - Exhibit changes of ARDS and microscopically show numerous fat globules within the microvasculature Brain - Lesion here include cerebral edema, red petechiae and microinfarcts, with fat globules also seen in microvasculature.

Question 38

Fat embolism is usually considered a direct result of what?

Answer 38

Trauma, with fat entering ruptured capillaries at the site of the fracture.

Question 39

what causes thrombocytopenia in fat embolism

Answer 39

Platelets adhere to the fat globules, causing thrombocytopenia

Question 40

T or F, Fat emboli are usually clinically inapparent

Answer 40

True, Fat embolism occurs in about 90% of patients with severe skeletal injuries, but less than 10% of such patients have clinical findings

Question 41

What are the 4 most common end-locations for arterial emboli

Answer 41

Cerebral Spleen Renal Intestine

Question 42

What are the clinical expressions of the 4 most common end-locations for arterial emboli?

Answer 42

Cerebral - Lodge in the middle cerebral artery and causes infarcts of the basal ganglia Spleen - Sharp subcostal pain Renal - Hematuria Intestine - Results from embolus that lodges in one of the major intestinal arteries, causing gangrene and necrosis of the bowel

Question 43

What is LPS and how it functions

Answer 43

LPS- found in bacterial cell wall of G- bacteria | - Complex binds to receptors on white blood cells and tissue cells, causing release of inflammatory mediators.

Question 44

How is septic shock and LPS related

Answer 44

Septic shock is caused by endotoxin-producing G- bacteria

Question 45

What is Waterhouse-Freidrichsen syndrome

Answer 45

Bilateral adrenal hemorrhage | - Shock due to massive adrenal hemorrhage (possible due to G- bacteria Nesseira mengitidis and E. coli

Question 46

How is Waterhouse-Freidrichsen syndrome associated with shock?

Answer 46

It has to do with septic shock

Question 47

Describe Red Infarcts

Answer 47

Are typical of venous obstruction involving the intestines or testes. The venous circulation may be interrupted as a result of twisting of the organ around its supporting structure.

Question 48

Other than intestines or testes, red infarcts are also typical of what organs

Answer 48

Those that have dual blood supply. Such as liver or lungs

Question 49

Describe White (pale) infarcts

Answer 49

Typical of arterial occlusion in solid organs such as heart or kidney

Question 50

T or F, the area of ischemic necrosis caused by the arterial obstruction is typically darker than the surrounding tissue when speaking of white infarcts

Answer 50

False, They are typically paler than surrounding tissue.

Question 51

T or F, Ischemic necrosis due to infarction in organs like the heart cannot be repaired except by replacement of damaged cells with fibrous tissue, resulting in myocardial fibrosis and scarring

Answer 51

True

Question 52

Can necrotic brain cells be replaced?

Answer 52

They cannot be replaced by regeneration either but fibrous scars do not form