Cell Death and Perfusion Disorders II Flashcards
what is a thrombus
blood clot
what is an embolus
piece of free-floating foreign material in the blood
thromboembolus
an embolus derived from a thrombus
watershed area
a region of the body that receives dual blood supply from the distal branches of two large arteries
end-artery
an artery that is the only supply of oxygenated blood to a portion of a tissue
examples of tissues that receive end-artery supply
regions of kidney, spleen, liver, intestine, heart, brain
sequela
condition that is a consequence of a previous disease or injury
amorphous
no clearly defined shape or form
what percentage of body weight is water
60%
what is the distribution of water in the intracellular and extracellular environment
2/3 intra
1/3 extra
what is the distribution of plasma and interstitial fluid
80% interstitial; 20% plasma
causes of edema (4)
- increased MICROvascular permeability
- increased hydrostatic pressure inside vessels
- decreased oncotic pressure inside vessels
- decreased lymphatic drainage
causes of increased HP inside vessels
hyperemia or congestion
causes of decreased OP inside vessels
decreased production of or excessive loss of albumin
gross morphology of edema
swelling of tissues; extra fluid in a cavity; can be clear or yellow
histologic morphology of edema
amorphous, pale eosinophilic fluid
how does pulmonary edema appear
foamy
edema in the chest cavity is called
hydrothorax
edema in the abdominal cavity is called
ascites
what region of tissue will get edema first
subcutaneous layer (takes path of least resistance)
what are two consequences of edema
fibrosis and compression of the organs in the space the fluid occupies
severity of edema depends on (2)
duration and location
what is hyperemia
increase in blood supply to an organ or tissue
what does hyperemia indicate
an adaptive circulatory response (increased oxygen demand, inflammation, heat dissipation)
clinically what is hyperemia important
it indicates an underlying condition (ex. why we check the sclera of an animal for redness)
what is congestion
accumulation of blood in a vascular bed die to reduced or obstructed OUTFLOW
what is an example of congestion that is an artifact and not a significant finding
hypostatic congestion
are arteries or veins the first to get congested in intestinal torsion
veins (thinner walled)
congestion in the intestines due to torsion would cause what pattern
segmental
how does right sided heart failure cause ischemic necrosis in the liver
right-sided heart failure -> congestion in systemic circulation -> elevated central venous pressure -> congestion in zone 3 -> ischemic necrosis
what pattern does ischemic necrosis in the liver cause
zonal (nutmeg liver)
how does left-sided heart failure impact the lungs
left-sided heart failure -> congestion in lung circulation -> blood accumulates in alveoli -> RBC breakdown in alveoli -> pigments accumulate in macrophages (ex. hemoglobin)
what does congestion predispose to (3)
thrombosis (due to abnormal blood flow), edema (due to increased HP), tissue hypoxia (dilution of oxygenated blood entering tissue since deoxygenated blood cannot leave)
what is involved in hemostasis (3)
endothelial cells, platelets, coagulation factors
what conditions are caused by altered hemostasis
hemorrhage or thrombosis(2)
what is hemorrhage
extravasation of blood
gross appearance of hemorrhage
free blood in space or cavity; appears bright red to red-blue in tissue and does not conform to a vascular pattern
does congestion conform to a vascular pattern
yes! (how you can tell whether it is congestion or hemorrhage)
histologic appearance of hemorrhage
RBCs outside of blood vessels; may see macrophages breaking them down
hemorrhage that is 1-2 mm is called ___________ whereas hemorrhage that is 1-2 cm is called __________
petechiae; ecchymoses
a palpable mass of hemorrhage is called
hemotoma
a pattern created by some forms of hemorrhage is
paintbrush
hemopericardium can cause
cardiac tamponade
a black mass of clotted blood indicates
exposure to acids (ex. bleeding ulcers in the stomach due to erosion of the mucosa)
localized and/or slow hemorrhage causes (2)
hematoma; anemia
widespread and/or fast hemorrhage causes (4)
anemia; decreased perfusion; shock; death
what is virchow’s triad
predisposing factors to thrombosis:
1. abnormal blood flow
2. endothelial injury
3. hypercoagulability
name 2 causes of hypercoagulability
enhanced platelet activity, increased clotting factor activation
name 2 causes of abnormal blood flow
aneurysm, cardiac disease, local stasis, hypovolemia
name 2 causes of endothelial injury
toxins (ex. endotoxin), viruses, bacteria
sequela of thromboembolism
sepsis if infected; distant infarction
name 4 fates of a thrombus
lysis, incorporation, recanalization, embolization
