CH 4 part. 1 Flashcards
What is edema?
Accumulation of fluid in the interstitial (body cavities) due to increased hydrostatic and decreased oncotic pressures.
Anasarca
system malfunction (liver failure, renal failure, right side heart failure) that induces general systemic edema.
Types of edematous fluid collection
Hydro - thorax, pericardium, peritoneum (ascites)
parasitic filariasis
parasitic worm that causes fibrosis of inguinal lymphatics and lymph nodes causing elephantitis
complication of upper extremity edema?
breast cancer removal. exacerbate UE edema due to physical removal of lymphatics (decrease drainage and increase edema)
Increased hydrostatic pressure due to?
mainly impaired venous return
Reduced oncotic pressure due to?
sever liver disease and malnutrition
Sodium and water retention due to?
renal failure (which can be caused by congestive heart failure).
Causes of lymphedema?
Chronic inflammation, invasive tumors, physical removal, radiation,
Sub Q edema
dependent edema (due to gravity), and Pitting edema
Edema secondary to renal dysfunction
Periorbital edema. affects Loose CT
Sub Q (soft tissue) edema importance signals?
signals underlying cardiac, renal diseases. affects wound healing and clearance
Pulmonary edema
seen with Left ventricular failure. pink, frothy fliud (extravasated RBC)
Brain edema (general)
brain swollen with narrow sulci and distended gyri. compression against skull.
Brain edema (severe)
brain substance herniation through the foramen magnum. compression of vasculature (ischemia)
Hyperemia
active process. arteriolar dilation (increase blood flow- oxygenated blood) inflammation and exercise.
congestion
passive process. reduced outflow of blood (cardiac failure)
local congestion
venous obstruction (cyanosis, stasis)
chronic congestion
chronic hypoxia (ischemia and scar), capillary rupture (hemorrhage foci)
Telltale sign of chronic congestion- capillary rupture?
hemosiderin-laden macrophages
Acute pulmonary congestion
engorged alveolar capillaries -> alveolar septal edema -> intra-alveolar hemorrhage
chronic pulmonary congestion
septa thick and fibrotic (no edema), hemosiderin-laden macrophages (HF cells)
Acute hepatic congestion
distension of central vein and sinusoids. potential centrilobar ischemia (distal end)
chronic passive hepatic congestion
centrilobar are red-brown color due to cell death and located around uncongested tan liver (nutmeg liver)
Hepatic microscopic examination- overveiw
Centrilobar hemorrhage, hemosiderin-laden macrophages, and variable degeneration of hepatocytes
What is a hemorrhage?
extravasation of blood to extravascular space
external hemorrhage?
hematoma
Petechiae hemorrhage
small 1-2mm in skin, mucous, serosal. Associated with: increased intravasc pressure, low platelet (thrombocytopenia), and defective platelet function (uremia)
Purpura
> 3mm hemorrhage. Associated to trauma, vasculitis, amyloidosis, and indication for petechiae
ecchymoses
sub Q hematoma (bruise). change of color due to Hemoglobin (red/blue) -> bilirubin (green/blue) -> hemosiderin (yellow/brown)
Normal Hemostasis
tightly regulated. form clots, keep blood fluid
Thrombosis
blood clot formation
components of hemostasis/thrombosis
vascular wall, platelets, coagulation cascade
arteriolar vasoconstriction
immediate vasoconstriction to site of injury
Primary hemostasis
formation of platelet plug. vWF and collagen promote platelet adherence and activation (shape change and degranulation)
Secondary hemostasis
deposition of fibrin. Tissue factor coag cascade- thrombin generation - fibrin meshwork.
Clot stabilization and resorption
tissue plasminogen activator (t-PA) to limit clotting and resorb clot.
endothelial cells
anticoagulation. when activated- procoagulation.
Endothelial antiplatelet
prevent platelet adherence to collagen (vWF) due to NO and PGI2
Endothelial antiplatelet ADP
degrades ADP, therefore inhibits aggregation of platelets
Endothelium anticoagulant
thrombomodulin binds to thrombin to convert to anticoagulant. Activating protein C to inhibit factor 5a and 8a.
Endothelium anticoagulant heparin-like
endothelium surface bind and activate antithrombin 3 (indirect activation)
endothelium anticoagulant tissue factor path
cell surface protein that inactivates factors: 7a and 10a
endothelium fibrinolytic effect
tissue plasminogen activator (t-PA) cleaves plasminogen to plasmin which cleaves fibrin and degrades thrombi
platelets attaché to what on endothelial surface
vWF (collagen)
procoagulant effects of endothelial cells
synthesize tissue factor. activate factors 9 and 10
antifibrinolytic effects
activated endothelial cells secrete inhibitors of plasminogen activator (PAI)
Bernard- Soulier syndrome
deficiency of GpIb (no platelet binding to vWF)
Glanzmann thrombasthenia
deficiency of GpIIb-IIIa (no platelet-fibrinogen-platelet binding)
von Williebrand disease
deficiency of vWF
platelet alpha granules
P-selectin for adherence to collagen
Platelet delta (dense) granules
contain ADP (platelet aggregation), ATP, calcium (for coagulation cascade), histamine.
platelet activation
negatively charged phospholipids on their surface bind to calcium
