Lecture 4 - Edema/ Cogestion/ Hemostasis

Question 1

what is the definition of edema

Answer 1

fluid in tissue, anasarca refers to generalized and usually severe increase in fluid
-movement of fluid across capillary walls

Question 2

pathophysiology of edema: what is the effect of increased hydrostatic pressure?

Answer 2

impaired venous return (e.g. mechanical obstruction, congestive heart failure)

Question 3

pathophysiology of edema: what is the effect of reduced plasma osmotic pressure

Answer 3

• reduced protein (albumin) synthesis (e.g. cirrhosis)

- increased loss of protein (e.g. nephrotic syndrome, some forms of gastroenteropathy

Question 4

pathophysiology of edema: what is the effect of lymphatic obstruction

Answer 4

fibrosis, parasites, cancer, compression

Question 5

pathophysiology of edema: what is the effect of sodium and water retention

Answer 5

• acute impairment of renal function

- decreased renal profusion with release of renin (e.g. congestive heart failure)

Question 6

pathophysiology of edema: what is the effect of inflammation

Answer 6

increase vascular permeability, necrosis, angiogenesis

Question 7

what are the complications of edema?

Answer 7

1. Pulmonary edema impairs gas exchange (e.g. acute CHF)

2. Cerebral edema causes compression and herniation of critical areas, decreases blood flow

Question 8

what is the definition of effusion?

Answer 8

collection of fluid in body cavity r or other space

• pleural, pericardial, peritoneal (ascites), joint space (synovial)
• transudate or exudate

Question 9

definition of hyperemia

Answer 9

active vasodilation from neurogenic mechanisms or inflammation

Question 10

definition of congestion

Answer 10

impaired venous return often accompanied by edema

Question 11

examples of congestion (4 of them)

Answer 11

1. acute pulmonary congestion (e.g. after acute myocardial infarction)
2. Chronic pulmonary congestion with hemosiderin - laden macrophages (“heart failure cells”)
3. Chronic hepatic congestion produced the gross appearance of “nutmeg” pattern due to blood in the centrizonal sinusoids
4. Acute hepatic congestion can lead to ischemic necrosis of centrizonal hepatocytes (centrizonal necrosis)

Question 12

what is the definition of hematoma

Answer 12

blood in tissue (literally tumor of blood)

Question 13

definition of petechiae

Answer 13

skin or mucous membrane hemorrhages
1-2 mm in size

*petite, cute little things

Question 14

definition of purpura

Answer 14

skin of mucous membrane hemorrhages larger than 3-9 mm

Question 15

definition of ecchymoses

Answer 15

focal skin and subcutaneous hemorrhage, more than or equal to 1 cm

Question 16

hemothorax, hemopericardium, hemarthrosis (joint), hemoperitoneum are all under the broad category of…

Answer 16

hemorrhage

ok i admit this was a shitty question

Question 17

what are the clinical consequences of hemorrhage

Answer 17

• acute hemorrhage of more than 20% of blood volume leads to SHOCK
• chronic blood loss leads to iron deficiency anemia
  (nooooooo not more questions about the stupid anemias)

Question 18

What are the antithrombotic properties of hemostasis in reference to the endothelium

Answer 18

• barrier from extracellular matrix (ECM)

- prostacyclin (PGI2) inhibits platelet adhesion

Question 19

anticoagulant properties - heparin like molecules allows antithrombin III (AT III) to inactivate

Answer 19

thrombin, Xa and other factors

Question 20

anticoagulant properties - thrombomodulin bind to thrombin and this complex inactivates …

Answer 20

protein C

Question 21

anticoagulant properties - synthesis of protein S - it is a cofactor needed for…

Answer 21

full protein C function, inactivation of Va and VIIIa

Question 22

what physiological process is synthesis of tissue plasminogen activator (tPA) needed for

Answer 22

antigoagulation

Question 23

what are the three phases of forming the platelet plug?

Answer 23

adhesion, secretion, and aggregation

Question 24

what is the definition of adhesion in reference to the platelet plug?

Answer 24

mediated by von Willebrand factor which bridges b/w collagen and surface platelet receptor (glucoprotein Ib)

Question 25

what is the definition of secretion in reference to the platelet plug?

Answer 25

release of contents from both types of granules

• ADP mediates platelet aggregation and calcium is required for the coagulation cascade
• there is surface expression of phospholipid complex which is a binding sire for calcium and coagulation factors

Question 26

what is the definition of aggregation in reference to the platelet plug?

Answer 26

stimulated by ADP and thromboxane A2

• Thrombin derived from the coagulation cascade binds to a platelet surface receptor leading to more aggregation (reversible phase) and platelet contraction (irreversible phase)
• Fibrinogen binds to the platelet surface receptor GP IIb- IIIa and the platelet plug becomes cemented by fibrin

Question 27

coagulation cascade is a series of enzymatic conversion of inactive ____ to activated ______

Answer 27

inactive proenzymes to activated enzymes

Question 28

coagulation cascade - binding of calcium, active enzyme cofactor and substrate (the proenzyme) occurs at the..

Answer 28

phospholipid complex on platelet membranes

Question 29

in the coagulation cascade the extrinsic system is activated by…

Answer 29

tissue factor (thromboplastin)

Question 30

in the coagulation cascade the intrinsic system is activated by …

Answer 30

factor XII (hageman factor)

Question 31

the final products of both the intrinsic and extrinsic systems are….

Answer 31

thrombin and fibrin

Question 32

control of excess coagulation is by….

Answer 32

antithrombins (including (AT III) which inhibit activity of thrombin and other coagulation factors, and protein C and S which inactive factors Va and VIIIa

Question 33

fibrinolysis occurs by the activation of….

Answer 33

plasmin from plasminogen by tissue plasminogen activator (t-PA). plasmin breaks down fibrin to form fibrin split products