4.4 - Thrombosis

Question 1

what are lines of zahn? what are they used for?

Answer 1

• alternating layers of platelets / fibrin and RCBs

- used to differentiate thrombus from post-mortem clot

Question 2

will lines of zahn be present in a thrombus (pre-mortem) or post-mortem clot?

Answer 2

thrombus

Question 3

is PGI2 pro-thrombotic or anti-thrombotic?

Answer 3

anti (PGI2 inhibits platelet aggregation)

Question 4

how can vitamin B12 deficiency lead to endothelial damage?

Answer 4

decreased conversion of homocysteine to methionine resulting in buildup of homocysteine

Question 5

how does folic acid circulate in the serum?

Answer 5

methyl-THF

Question 6

what is the role of vitamin B12 in DNA synthesis?

Answer 6

B12 takes a methyl group from methyl-THF, allowing it to synthesize DNA precursors

Question 7

what does methyl-B12 do after receiving the methyl from folate?

Answer 7

transfers methyl to homocysteine, resulting in methionine

Question 8

how does cystathionine beta synthase (CBS) deficiency result in high homocysteine levels?

Answer 8

CBS converts homocysteine to cystathionine - defect results in buildup of homocysteine

Question 9

what is the inheritance of protein C/S deficiency?

Answer 9

AD

Question 10

what is the normal function of proteins C and S?

Answer 10

inactivate factors 5 and 8

Question 11

if PTT does not rise with heparin dosing, what disorder could you suspect?

Answer 11

AT3 deficiency