Robbins Ch 4: Hemodynamic Disorders, Thromboembolic Disease and Shock Flashcards
Elevated 1 or diminished 2 can disrupt the balance fluid movement across vessels leading to edema.
- hydrostatic pressure
2. colloid osmotic pressure
Accumulation of fluid within tissue is known as _
edema
Accumulation of fluid within body cavity is known as_
effusion
As a cause of edema, increase in hydrostatic pressure are mainly caused by disorders that impair _
Venous return
How does one with cirrhosis or nephrotic syndrome cause edema?
Both leads to diminished albumin which is the major protein in plasma responsible for oncotic pressure.
Dependent edema is commonly associated with edema in _
Lower extremity (gravity associated)
Periorbital edema is commonly associated with what disease?
severe renal disease. Renal dysfunction often appears initially in parts of the body containing loose connective tissue such as the eyelids.
Morphologically, what changes are seen in gyri and sulci in brain edema?
Narrowed sulci and distended gyri.
Peritoneal effusions results most commonly from 1 and are prone to 2.
- portal hypertension
2. seeding by bacteria, leading to serious and sometimes fatal infections.
Hyperemia and congestion both stem from increased _
Blood volume within tissues.
Hyperemia is _1_process in which arteriolar dilation leads to increased blood flow. Give an example of hyperemia.
- Active process
Example: site of inflammation or skeletal muscle during exercise
Congestion is a _ process resulting from reduced outflow of blood from a tissue.
passive
In long-standing chronic passive congestion, the associated 1 may result in 2 injury and scarring
- chronic hypoxia
2. Ischemic
In chronic congestion, why is clusters of hemosiderin-laden macrophages seen?
Capillary rupture which produce small hemorrhagic foci and subsequent catabolism of extravasated red cells leads to this appearance.
What is the morphology of acute pulmonary congestion?
Congested tissue usually appear dusky reddish-blue color. In acute pulmonary congestion, engorged alveolar capillaries, alveolar septal edema, and focal intraalveolar hemorrhage is seen.
What is the morphology of chronic pulmonary congestion?
The septa are thickened and fibrotic, and the alveoli often contain numerous hemosiderin-laden macrophages called heart failure cells.
What is the morphology of acute hepatic congestion?
Central vein and sinusoids are distended. The centrilobular areas may be necrotic while the periportal hepatocytes may only develop fatty changes.
What is the morphology of chronic passive hepatic congestion?
Contrilobular regions are grossly red-brown and slightly depressed (cuz of cell death) and are accenutated against the surrounding zones of uncongested tan liver (nutmeg liver). microscopically there is centrolobular hemorrhage, hemosiderin-laden macrophages and variable degrees of hepatocyte dropout and necrosis.
Arteriolar vasoconstriction occurs immediately and markedly reduces blood flow to injured areas mediated by _.
reflex neurogenic mechanisms and augmented by the local secretion of factors such as endothelin which is a potent endothelium-derived vasoconstrictor.
Primary hemostatsis is _
formation of the platelet plug
Explain what happens in primary hemostasis.
Disruption of endothelium exposes subendothelial vWF and collagen which promote platelet adherence and activation. Activation of platelet results in dramatic shape change (from round to disk), and release of secretory granules which recruits more platelets.
What is tissue factor and what role does it play in the secondary hemostasis?
Tissue factor is a membrane-bound procoagulant glycoprotein that is normally expressed by subendothelial cells. During injury tissue factor become exposed and binds and activates factor VII which sets in motion a cascade of reaction.
Explain what happens in secondary hemostasis.
Tissue factor binds and activates VII which sets in motion a cascade of reactions that culminates in thrombin generation. Thrombin cleaves fibrinogen to fibrin to create a fibrin meshwork. Thrombin is alos a potent activator of platelet leading to more platelet aggreation
Which cytoplasmic granules of platelets contain the P-selectin adhesion molecule?
alpah-granules
what are the contents of the dense granules of platelets?
ADP, ATP, ionized Calcium, serotonin and Epi.
What are the contents of alpha granules of platelets?
P-selectin, fibrinogen, caogulation factor V, vWF, fibronectin, platelet factor 4, PDGF, TGFbeta.
vWF interacts with what surface receptor on platelet?
GpIb
what acts as the bridge between the exposed collagen on endothelium and the platelet surface molecule GpIb?
vWF
Bernard soulier syndrome is a bleeding disorder due to genetic defect of what molecule?
GpIb
Once bound, platelet rapidly change shape. this change is accompanied by alterations in glycoproteins 1 that increases its affinity for 2 and by the translocation of negatively charged 3 to platelet surface.
- IIb/IIIa
- fibrinogen
- phospholipids (mainly phosphatidylserine. These serve as the nucleation sites for the assembly of coagulation factor complexes.
protease-activating receptor (PAR) is switched on by a proteolytic cleavage carried out by _
thrombin.
Recruitment of platelet occurs platelet activation and _ release.
ADP
Thromboxane A2.
During platelet aggregation, what forms a bridge between adjacent platelets, leading to their aggregation?
Fibrinogen
Glanzmann thrombasthenia is a bleeding disorder due to inherited deficiency of _
GpIIb/IIIa
In the coagulating cascade, Ca binds to 1 residues which are present on factors 2 ,3 , 4 and 5.
- gamma-carboxylated glutamic acid
- II
- VII
- IX
- X
What cofactor is required for the enzymatic reactions that produce y-carboxylated glutamic acid in the coagulating cascade?
Vitamin K
which factors are part of the intrinsic pathway in the coagulating cascade?
II, V, VIII, IX, X, XI, XII and fibrinogen
Which factors are part of the extrinsic pathway in the coagulating cascade?
II, V, VII, and X.