Hemodynamics Flashcards
artery or vein? label the layers from outer-most to inner-most
artery or vein? Label parts
vein
what structural components differentiates a vein and artery microscopically?
elastic lamina
define edema
abnormal accumulation of fluid in interstitium and tisssues
list the four main causes of edema
- increased microvascular permeability (leaky vessel)
- increased vascular hydrostatic pressure
- decreased intravascular osmotic pressure
- decreased lymphatic drainage
ID the pathologies and describe colors
edema
list the two main causes of non-inflammatory edema
hepatic failure
heart failure
describe the two pathologies that cause edema from liver failure
reduced albumin production > decreased oncotic pressure > edema
portal hypertension aka blocked blood from stomach/intestines to the liver > increased hydrostatic pressure > edema
how does heart failure (dec CO and RAAS) cause edema?
dec CO > dec BF to kidneys > kidney sense reduction in volume > inc fluid volume through Na and H20 by activating RAAS > inc reabsorption of sodium > water retention > inc hydrostatic pressure
renin production by RAAS > angiotensin converted to angiotensin II > angiotensin II causes vasoconstriction > inc hydrostatic pressure
angiotensin II stimulates secretion of ADH > inc water permeability in CD > inc water retention > inc hydrostatic pressure
define hyperemia. is it an active or passive process?
arteriolar dilation causing a local increase in volume of blood
active process
list ways in which hyperemia occurs
inflammation
physical activity
increased blood flow to GI after food
physiologic mechanism to dissipate heat
define congestion. is it active or passive?
passive
impaired/decreased outflow of blood
list ways in which congestion occurs
CHF
local venous obstruction
organ displacement
ID hyperemia or congestion
hyperemia - called erythema in the skin
ID hyperemia or congestion
congestion
ID hyperemia or congestion
CHRONIC congestion
define erythrophagocytosis
macrophages that contain whole RBCs
define hemosiderin-laden macrophages
brown, iron containing from breakdown of RBC
heart failure cells
define hemostasis
PHYSIOLOGICAL response to vascular damage and stops bleeding
define thrombosis
PATHOLOGIC activation of hemostatic process to induce clot
what is virchow’s triad?
factors that contribute to hemostasis and thrombosis
1. endothelial injury !!!
2. abnormal blood flow
3. blood hypercoaguability
describe the hemostatic process (4 steps)
- primary hemostasis - vasoconstriction and platelet aggregation to form platelet plug at damaged site
- secondary hemostasis - coagulation to form fibrin mesh
- fibrinolysis - remove platelet/fibrin plug
- tissue/vascular repair
what is von willebrand factor? what step of the hemostatic process is it involved in?
protein that helps blood clot - glue for platelets to bind to injury
primary hemostasis
what is tissue factor? what step of the hemostatic process is it involved in?
initiates extrinsic path of coagulation cascade
secondary hemostasis
describe the intrinsic coagulation cascade
factors 12 11, 9, 8 -> common path, factor 10 -> (prothrombin to thrombin factor 2) -> fibrinogen (1) -> fibrin clot
describe the extrinsic coagulation cascade
tissue factor 3 -> factor 7 -> common path, factor 10 -> (prothrombin to thrombin factor 3) -> fibrinogen -> fibrin clot
list the vitamin k dependent coag factors
factors 2, 7, 9, 10
1972
define fibrinolysis
prevents blood clots from forming pathogenic condition
describe the role of plasmin in the fibrinolytic system
digests fibrin clots and releases fibrin degradation products
inhibits additional fibrin formation
what’s the most important/potent coagulation inhibitor?
antithrombin 3 - made by endothelium and hepatocytes
what are the 3 major anticoagulant-antithrombotic systems on endothelial cells?
- protein C-protein S thrombomodulin system
- antithrombin III
- tissue factor pathway inhbitor
list the three hemorrhage descriptive terms
petechia
ecchymosis
suffusive
define petechia
pinpoint hemorrhage
minor vascular damage
define ecchymosis
more extensive vascular damage than petechia
define suffusive
larger, contiguous area of tissue hemorrhage damage
paintbrush
ID hemorrhage type
ID hemorrhage type
ID hemorrhage type(s)
- petechia
- ecchymosis
ID hemorrhage type
what does hemorrhage significance depend on?
amount, location, rate
large amounts > hypovolemia > decreased tissue perfusion > hypovolemic shock
exsanguination is __% of blood loss volume
40%
in which organs is it worst to have hemorrhage?
brain and heart - very little room to expand
define thrombus
group of platelets, fibrin, and other blood in injured blood vessel
physiologic vs persistent thrombus
physiologic - normal, rapidly resolves after healing
persistent - forms on wall of injured vessel (blood, lymphatic, or heart)
define thromboembolism
persistent thrombus that is free in a vessel lumen
list major determinants of thrombosis
VIRCHOWS TRIAD
*** alterations of endothelium to cause increased production of pro-coag substances
describe cardiac and large arterial thrombi
what is it initiated by?
firmly attached to vessel wall
lamellated appearance from rapid flow and alternating layers of platelets
tunucia intima is lost/damaged
initiated by endothelial damage
ID this pathology
cardiac/large arterial thrombi
describe venous thrombus
what is it initiated by?
dark red, gelatinous since large amount of erythrocytes loosely
incorporated into thrombus from slow BF
most are occlusive
become molded to shape of lumen of vein and grow upstream from site of initiation
initiated by areas of slow blood flow/stasis
ID pathology
venous thrombus
How are small thrombi resolved?
removed by thombolysis and BV returns to normal structure and function
How larger thrombi resolved?
removal of thrombotic debris by phagocytes > granulation tissue formation and fibrosis >regrowth of endothelium over surface of thrombi to incorporate the affected area into the vessel wall
How are large mural or occlusive thombi resolved?
growth of endothelial-lined blood channels through fibrotic area (recanalization)
what type of thrombus resolution is shown here?
recanalization
where do venous emboli typically lodge?
pulmonary circulation
causes R sided HF or infarcts
where do arterial thromboemboli lodge?
in the tissue that depends on it
ex: saddle thrombus
what two main things could occur due to occlusion of a vessel?
hypoxia
infarct
what’s occurring here?
infarct
define acute red infarct
red, often swollen or slightly raised
cause: hemorrhage
define subacute pale infarct and pathogenesis
pale
necrosis > swelling > forces blood out of infarcted region > pale appearance
define chronic infarct
pale, shrunken, firm, fibrosis
describe the concept of disseminated intravascular coagulation (DIC)
endothelial damage > microvascular thrombosis > too much clotting and usage of factors > ischemia in one organ/area > lack of clotting factors in rest of body so too much bleeding in other areas
describe the infarct
acute red infarct
describe the infarct
subacute pale infarct
describe the infarct
chronic infarct
