Test 1: lecture 8 circulatory disturbances Flashcards
function of circulatory system
Deliver nutrients to & remove waste products from cells
Circulate fluid & cells to maintain homeostasis & integrate function
breakdown of water inside the body
what is the outward pressure in blood vessels
hydrostatic
what is the pull caused by proteins called
osmotic pressure
fluid accumulation in tissues
edema
fluid accumulation in body cavities
effusion
Imbalance between intravascular & interstitial compartments cause ____
fluid accumulation in the interstitium
what does edema look like microscopically
4 causes of edema/effusion
increased vascular permeability
- increased intravascular hydrostatic pressure
- decrease plasma colloid osmotic pressure
- decrease lymphatic drainage
an increase or decrease in osmotic pressure would cause edema
decrease (osmotic pressure pulls fluid back into the blood vessels)
how does inflammation cause increased vascular permeability?
local release of inflammatory mediators such as histamine, bradykinin and leukotrienes
increased hydrostatic pressure is due to ___
increased blood volume in microvasculature
(localized or generalized)
due to impaired venous outflow
increased intravascular hydrostatic pressure is usually due to impaired ___
venous outflow (passive congestion)
2 common ways to have low protein
protein loss through the kidneys or GI
or decreased protein synthesis due to liver failure or poor nutrient
hypoproteinemia causes ___ plasma colloid osmotic pressure
decreased → leads to edema
edema caused by low osmotic pressure is usually generalized or local?
generalized (all over decrease in protein, either from loss or from decreased synthesis)
what are some causes of decreased lymphatic drainage
Compression or blockage due to trauma, fibrosis, invasive neoplasms, infectious agents, or congenital malformation (rare)
lymphatic obstruction would increase or decrease lymphatic drainage
decrease (blockage in vessel prevents it from carrying away lymph)
where are two places edema is bad
cerebral and pulmonary/thoracic
(have no place to swell)
primary hemostasis is mediated by ___
platelets
secondary hemostasis is mediated by ___
clotting factors
what happens during primary hemostasis
vasoconstriction→ tries to reduce size of injury
collagen in wall of vessel exposed and triggers vWF to cause platelets to bind and clump
what happens during secondary hemostasis
tissue factor cause coagulation cascade → thrombin formation which leads to fibrinogen into fibrin
___ is blood loss from the
circulatory system
hemorrhage
3 causes of hemorrhage
blood vessel injury
decreased platelets
decreased clotting factor
decreased number of platelets can be caused by
platelets not being made, not working right or being destroyed or used up
decreased production of platelets
increased consumption/destruction
decreased function
what kind of cells make most clotting factors
hepatocyte in the liver
many clotting factors are vitamin ___ dependent
K
needs to be recycled
hemorrhage is bad where?
___ is inappropriate clotting within the circulatory system
thrombosis
aggregate of platelets, fibrin, & other blood elements formed on
a vessel or heart wall
thrombus
If a thrombus (or fragment of a thrombus) breaks loose and enters the circulation, it becomes a ____
thromboembolus
when a piece of a blood clot breaks off and travels it is called a ___
thromboembolus
embolus
any mass (solid, liquid, or gas) carried by the blood from its point of origin to a distant site, where it often causes tissue dysfunction or necrosis
___ = any mass (solid, liquid, or gas) carried by the blood from its point of origin to a distant site, where it often causes tissue dysfunction or necrosis
embolus
embolism
(bone marrow in lung tissue)
what do thrombi look like
dull, rough, red/tan, friable
laminated
can be occlusive or non occlusive
difference between thrombi and postmortem blood clot
thrombi: dull, rough, red/tan, friable, laminated
postmortem: shiny, smooth, gelatinous
thrombi or post mortem clot?
thrombi → dull, rough, red/tan, friable
3 sides of virchow’s triad
endothelial injury, abnormal blood flow and hypercoagulability are all part of ___
virchow’s triad
(cause a clot)
If thrombosis is widespread, it can lead to a ___ & subsequent ___
consumptive coagulopathy
hemorrhage
(DIC- too much clotting, use up all the factors, flips and leads to uncontrolled bleeding)
Systemic ____influences help maintain adequate blood flow to the tissues
neural & hormonal
____= active engorgement of a vascular bed due to vasodilation & increased flow
hyperemia
passive engorgement of a vascular bed due to decrease outflow
congestion (blood not draining well)
hyperemia vs congestion
hyperemia: active increase of blood to an area→ vasodilation and increased blood flow
congestion: decrease in blood draining (passive) (CHF or obstruction)
CHF is an example of hyperemia or congestion
congestion (passive inability to move blood out)
blood pooling
grossly what does hyperemia look like
warm and bright red due to increased oxygenated blood to an area
(running get flushed)
grossly what does congestion look like?
cool and dark red/purple
pooling of deoxygenated blood
stagnation
Inadequate tissue perfusion
ischemia
ischemia
decreased blood flow caused by obstruction, congestion or decreased cardiac output
what three things happen during ischemia
decreased O2 delivery
decreased nutrient delivery
decreased waste removal
what organs are most susceptible to ischemia
brain and heart
high O2 need and poor collateral circulation
area of tissue necrosis due to ischemia
infract
cell death of tissues due to decreased blood flow
acute/subacute phase of infarct look ___
wedge shaped
swollen and dark red (hemorrhagic) or tan
chronic infracts grossly look ___
depressed, tan and firm
tissue has been replaced by fibrous material that shrinks during healing
a state of general circulatory failure that impairs tissue perfusion → cellular hypoxia ± cell injury & death
shock
cardiogenic shock
decreased cardiac output from heat failure
(pump doesn’t work)
decreased cardiac output due to heart (pump) failure
cardiogenic shock
hypovolemic shock
decreased circulating blood volume due to massive fluid loss/hemorrhage
HYPOVOLEMIC SHOCK
heart/pump fine but not enough blood to pump through body due to fluid loss
(hemorrhage, diarrhea, vomiting, burns)
distributive shock
decreased peripheral vascular resistance with pooling of blood in peripheral tissue due to sepsis, anaphylaxis
vasodilation
decreased peripheral vascular resistance with pooling of blood in peripheral tissues due to sepsis, anaphylaxis, etc.
distributive shock
When that fluid accumulates in tissues
edema
mesocolonic edema
translucent yellow jelly- like appearance due to accumulation of fluid in the interstitial space.
“bottle jaw” refers to fluid build up ___
submandibular edema
“brisket edema”
pectoral edema
When excess fluid accumulates in a body cavity, we call it an ___
EFFUSION.
hydrothorax
hydropericardium
serous effusion in the peritoneal cavitity
hydroperitoneum
ascites
ascites
serous effusion in the peritoneal cavity
ASCITES
serous effusion in the peritoneal cavity
4 causes of edema
increased vascular permeability, which occurs during ___
inflammation
Inflammatory stimuli lead to local release of inflammatory mediators that cause ____ of the gaps between vascular ____cells.
vasodilation and widening
endothelial
exudate
fluid, proteins and cells that leave vessels due to increased vascular permeability, high specific gravity
leakage of plasma proteins and emigration of leukocytes
urticaria (hives)
dermal edema
blue → eosinophilic inflammation
green → edema
increased intravascular hydrostatic pressure can be due to an active increase in blood flow into the microvasculature called ___
hyperemia
hyperemia can be caused by acute inflammation or by ___
congestion - passive accumulation of blood due to impaired venous outflow
passive accumulation of blood due to impaired venous outflow.
(CONGESTION)
congestion causes increased blood volume that will increase ___ that will drive fluid from the intravascular compartment into the interstitium, resulting in ___
hydrostatic pressure
localized edema.
right sided heart failure
blood backs up into the body → SQ edema and ascites (cavitary effusions)
left sided heart failure
blood backs up into the lungs
pulmonary edema
pulmonary edema
heavy and exude frothy or watery (serous) fluid when incised
Fluid also expands the connective tissue septa of the lung, giving the septa a widened gelatinous appearance
pulmonary edema vs pleural effusion
pulmonary edema- fluid buildup in the lungs
pleural effusion- fluid buildup around the lungs
Low plasma protein concentration
hypoproteinemia
2 ways to have decreased osmotic pressure
protein loss through GI or kidneys
decreased protein synthesis (liver failure)
insufficient intravascular colloid osmotic pressure for fluid resorption from the interstitium, leading to ___
generalized edema.
what plasma protein is important for osmotic pressure
albumin
In cases of end-stage liver disease, there is decreased functional hepatic mass, which leads to decreased synthesis of plasma proteins by the liver. The resulting hypoproteinemia leads to decreased ___ and subsequent ___
plasma colloid osmotic pressure
edema/effusion
cirrhosis of the liver
cirrhosis will cause decreased ___ and increased ___
osmotic pressure → edema
hydrostatic pressure → fibrosis will impede normal hepatic blood flow and increase hydrostatic pressure which leads to ascites (edema in body cavity)
ascites
can be caused by increased hydrostatic pressure or decreased osmotic pressure from liver damage
Decreased lymphatic drainage can be the result of lymphatic vessel ___ and is usually localized to a particular region.
compression or blockage
congenital lymphedema.
lymph vessels do not grow all the way→ blunt end
leads to build up of lymph → edema
(mechanisms intended to seal an injured vessel and prevent blood loss
hemostasis
3 causes of hemorrhage
blood vessel injury
decreased platelets
decreased clotting factors
___ is required for normal collagen cross-linking, which helps maintain the integrity of blood vessel walls
Vitamin C→ scurvy
periarticular
occur around a joint
scurvy in guinea pigs
low Vit C leads to misformed collagen → weak cell walls → hemorrhage near joints
periarticular hemorrhage
scurvy
low Vit C → can’t make collagen correctly
vessels are weak and prone to periarticular hemorrhage
3 reasons to have low platelets
decreased platelet production
increased consumption or destruction of platelets
decreased platelet function
Without adequate platelets, primary hemostasis (formation of a platelet plug) cannot be achieved after blood vessel injury, resulting in ___
hemorrhage.
formation of a platelet plug
primary hemostasis
(low platelet count
thrombocytopenia
the cells responsible for production of platelets in the bone marrow
megakaryocytes
formation of a fibrin meshwork
secondary hemostasis
rodenticide poisoning leads to ___ why?
hemorrhage
messes up coagulation factor → Vit K can’t be recycled
Anticoagulant rodenticides contain vitamin K antagonists, such as warfarin or brodifacoum, that inhibit vitamin K epoxide reductase in the liver, leading to decreased amounts of active reduced vitamin K. Without active vitamin K, there is decreased production of vitamin K-dependent coagulation factors (II, VII, IX, and X). This acquired clotting factor deficiency can result in severe hemorrhage.
HEMARTHROSIS
blood in a joint cavity (we see this a lot in horses with traumatic racing injuries
blood in a joint cavity (we see this a lot in horses with traumatic racing
injuries
HEMARTHROSIS =
cardiac tamponade
When fluid accumulates in the pericardial sac, it can put pressure on the heart and prevent the heart from filling normally with blood
Very small hemorrhages (up to ~ 1-2 mm diameter) on the skin, mucosal, or serosal surfaces are referred to as
petechiae (petechia singular)
larger hemorrhages (up to ~ 2-3 cm diameter) are referred to as
ecchymoses (ecchymosis)
petechia
ecchymoses
Leakage of blood from injured vessels beneath an intact surface (such as the skin) is known as ___
contusion or bruise
If blood accumulates in a tissue to the point that it forms a visible mass, it is called a ___
hematoma
Virchow’s triad
another name for saddle thrombus
Feline Aortic Thromboembolism, or FATE
thrombus look ___
dull, rough, red/yellow and friable
thromboembolus in cats usually occur because of ___
hypertrophic cardiomyopathy (HCM)
the left ventricular myocardium hypertrophies and the left atrial chamber dilates. Dilation of the left atrium leads to alterations in blood flow (stasis or turbulence), which predispose to thrombus formation on the atrial wall (indicated by the green arrow in the image below). Thrombi are friable and can easily break apart, sending fragments (thromboemboli) into the circulation that can lodge at distant sites like the aortic bifurcation and block blood flow.
what two colors can be found in a post mortem clot
currant jelly
chicken fat
decreased tissue perfusion
ischemia
If perfusion is not rapidly restored, the tissue normally supplied by the affected vessel can undergo ___ due to insufficient blood supply.
coagulative necrosis
area of tissue necrosis caused by ischemia
infarct
___ are usually sharply demarcated and angular or wedge-shaped.
Infarcts
renal infarct
splenic infarcts from a dog. The infarcts are the discrete swollen angular tan foci with dark red (hemorrhagic) rims (separated by the lighter red splenic parenchyma).
These are cutaneous infarcts from a pig. The infarcts are the discrete rhomboidal red foci. These lesions are caused by Erysipelothrix rhusiopathiae infection, and the condition is commonly referred to as “diamond skin disease” (you can guess why). This bacterial infection causes necrosis of dermal blood vessels, which leads to thrombosis and cutaneous infarcts.
Active engorgement of a vascular bed
hyperemia caused by inflammation or increased metabolic activity
HYPEREMIA usually occurs due to ____ or ___metabolic activity
inflammation
increased
Hyperemic tissues are usually ___due to increased delivery of ___
warm and bright red
oxygenated blood.
Passive engorgement of a vascular bed
congestion → passive
CONGESTION usually occurs due to decreased ___
venous outflow.
Congested tissues are usually ___ due to accumulation of ___blood.
cool and dark red to blue
deoxygenated
right sided heart failure
leads to build up in body
SQ edema and ascites
left sided heart failure
build up in the lungs
pulmonary edema
left-sided heart failure.
The patchy dark red coloration of the lungs is due to ____ (passive accumulation of blood in the pulmonary venous system). The excess blood causes ____ that drives fluid out of the vessels into the interstitium, resulting in pulmonary edema.
pulmonary congestion
increased hydrostatic pressure
right-sided heart failure.
The regular pattern of dark red coloration is due to ___ (passive accumulation of blood in the vasculature) in the centrilobular regions of the liver. This condition is often referred to as ___
hepatic congestion
nutmeg liver
nutmeg liver caused by right sided heart failure
