2.5 Path: Vascular disease and would healing

Question 1

What is transudate?

Answer 1

fluid only

Question 2

What is exudate?

Answer 2

Fluid + cells

Question 3

What does pulmonary edema look like histologically?

Answer 3

Pink fluid in alveolar spaces

Serous fluid “Transudate”

Question 4

With blood, what is congestion?

Answer 4

passive vascular dilatation from reduced outflow. Increased red blood cells within blood vessels.

Question 5

What is hemorrhage?

Answer 5

leakage of red cells into tissue

Question 6

What is liver passive congestion?

Answer 6

Congestion common in liver, generally in setting of heart failure—> R heart failure, backflow, blood pools in the liver
Passive congestion of the liver aka nutmeg liver

Question 7

What is hemostasis? Generally, how does this occur?

Answer 7

Hemostasis= stopping blood flow (aka clotting)
Endothelial cell senses injury to self or nearby—> contrivers vasoconstriction —> IMPORTANT: activate platelets —> Platelets lay down over site on injury, forming platelet plug over damaged endothelium; if severe the signal is more intense then the Coagulation cascade is activated. This is a family of circulating proteins the quickly start forming products (eg fibrin and more) to heal defect in vessel END: form a thrombus (made of fibrin + RBCs)

Question 8

What is thrombosis? Generally, how does this occur?

Answer 8

Why does this happen? Virchow’s triad- endothelial injury, abnormal blood flow (eg aneurism, other defect), or hypercoagulablity (can be from inflammation, immune injury, cancer).

Question 9

What is Virchow’s triad?

Answer 9

Endothelial injury
Abnormal blood flow
Hypercoagulability
= thrombosis

Question 10

How do you go from oxygen depletion in tissue to thrombus?

Answer 10

Infarct—> Widespread endothelial event —> clotting cascade —> thrombus

Question 11

Histologically, what is a thrombus? Why are they multicolored?

Answer 11

Intralumenal mass with mix of red blood cells, platelets and fibrin
Components separate into areas by molecular weight which appear alternating light and dark .

Question 12

What are the potential fates of a thrombus?

Answer 12

Things they can do: (these options aren’t mutually exclusive)
Propagating- when a thrombus grows within the vessel
Dissolve- A natural system of fibrinolytic factors that break down clots (anti-fibrin factros) **best resolution is for body to break clots down
Reorganization and recanulazation: Eventually, the body will “take over” or “absorb” the thrombus and form a new channel through it
Embolism- Break off and travel elsewhere: typically causes the most damage

Question 13

How does a thrombus organize and recanulize?

Answer 13

After 5-7 days, migration of fibroblasts and onset of angiogenesis within thrombus
Forms granulation tissue. “organizes”
After several days, get a response from fibroblasts outside the vessel. Angiogenesis begins. In time, new tissue “plug” is formed =granulation tissue” , and a channel can be formed through the clot. In time, the clot should remove, Depends on flow and blood access.
10-14 days, angiogenesis results in new vessels with lumens within thrombus, beginning flow or “recanulization”

Question 14

What is en embolism? What are some common examples?

Answer 14

Detached solid, liquid or gaseous mass carried by blood to distant site from origin
Common types: Thromboembolism, Bone marrow embolism, Air Embolism

Question 15

What is the difference between red infarct and white infact?

Answer 15

Red infarct is dead tissue that has RBCs in it because the tissue has more than once blood source. Eg lung tissue
White infarct is dead tissue absent RBCs because the one source was cut off

Question 16

What is atherosclerosis?

Answer 16

Disorder resulting in arterial lesions called Atheroma or Atheromatous Plaques
Raised lesions in the intima which protrude into the lumen resulting in turbulent blood flow
Causes 50% of deaths in developed world
Etiology unclear..chronic inflammation/healing response?

Question 17

How does atherosclerosis form? At the tissue level.

Answer 17

Endothelial cells compromised, leak, allow cells from bloodstream esp. macrophage to enter the wall of the artery (inside wall of artery) and lipid leaks in as well (association with cholesterol). Once the macrophage is in the wall, they secrete factors that create lead to plaque development

Question 18

What is the first sign of the formation of atheromatous plaque?

Answer 18

Fatty streak: earliest lesion, lipid filled macrophages within intima

Question 19

Histologically, what is atherosclerotic plaque?

Answer 19

A complex, raised lesion with smooth muscle cells, macrophages, T cells; collagen; lipid

Question 20

What is a foam cell?

Answer 20

A macrophage filled with lipid

Question 21

What is the general sequence in wound healing?

Answer 21

Complex ordered process
Acute inflammatory response
Migration of epithelial and connective tissue
Angiogenesis
Extracellular matrix synthesis
Collagen synthesis and remodeling

Question 22

What happens in the first 24 hours after injury?

Answer 22

Acute Inflammatory Response
Neutrophil Infiltration
Erythema, Edema

Question 23

What happens 24-48 hours after injury?

Answer 23

Acute inflammatory response goes away, neutrophils die from apoptosis
Fibroblasts and microphages recruited to site- they simulate angiogenesis
See early bridging of new epithelial cells
Platelets and fibrin recruited to site- make a seal/scab.. form “fibrin cap”

Question 24

What happens on day 3 of wound healing?

Answer 24

Macrophages replace PMN’s
Granulation tissue invades wound space
Continued epithelial thickening

Question 25

What happens on day 5 of wound healing?

Answer 25

Maximal angiogenesis and granulation tissue
Collagen bridges wound
Epithelium restored

Question 26

What happens in the second week of wound healing?

Answer 26

Fibroblast proliferation and collagen synthesis
“Blanching”
Decreased vessels and edema
Resolution of inflammation Infiltrate

Question 27

What happens about a month into wound healing?

Answer 27

Cellular connective tissue
Progressive increase of tensile strength over next several months
Blood vessels have matured
Collagen lines up in a functional way to

Question 28

What is healing by first or second intention?

Answer 28

healing by 1st intention- the previous sequence, normal healing
healing by 2nd intention- more granulation, more inflmamtion, can take months to fill in , heals from outside in eg pressure sores, ulcers

Question 29

What are the characteristics of secondary healing?

Answer 29

More intense inflammation
More granulation tissue
Dramatic  wound contraction
10% of original size
Myofibroblasts