Hemostasis and related

Question 1

5 ways in which endothelial cell prevent thrombosis

Answer 1

1 - physical barrier (to subendothelial collagen and TF)
2 - produces prostacyclin (PGI2) and NO - vasodilate and inhibit platelet aggreg
3 - produces heparin-like molecules - augment antithrombin III
4 - secretes tPA
5 - secretes thrombomodulin - redirect thrombin to activate protein C –> inactivate factors V and VIII

Question 2

Functions of tPA

Answer 2

Converts plasminogen to plasmin:
1 - cleaves fibrin and serum fibrinogen
2 - destroys coag factors
3 - block platelet aggregation

Question 3

2 causes of elevated homocysteine

Answer 3

1 - Folate/B12 deficiency

2 - cystathionine beta synthase (CBS) deficiency

Question 4

Features of CBS deficiency

Answer 4

• vessel thrombosis
• mental retardation
• lens dislocation
• long slender fingers

Question 5

Causes of hypercoagulable state

Answer 5

1 - protein C/S deficiency
2 - Factor V Leiden
3 - Prothrombin 20210 A 
4 - ATIII deficiency
5 - oral contraceptive use

Question 6

Types of embolism

Answer 6

• Thromboembolism (95%)
• Atherosclerotic embolism: cholesterol clefts
• Fat embolism: fracture/soft tissue TR
• Gas embolism: decompression sickness (bends and chokes)
• Amniotic fluid emboism

Question 7

What is Caisson disease

Answer 7

Chronic form of decompression sickness (gas embolism) characterised by multifocal ischemic necrosis of bone

Question 8

Lab findings in Fe deficiency anemia

Answer 8

Smear: microcytic, hypochromic RBCs with increased RDW; pencil cells
Decreased ferritin, increased TIBC, decreased serum iron and % saturation
increased free erythrocyte protoporphyrin (FEP)

Question 9

Features of Plummer-Vinson syndrome

Answer 9

Fe-deficiency anemia with esophageal web and atrophic glossitis
Presents as anemia, dysphagia, beefy-red tongue