Thrombocytes

Question 1

how thrombocytes are formed

Answer 1

stem cells in marrow, pieces of precursor cell= megakaryocyte cytoplasm, nucleus gets phagocitized

Question 2

thrombocyte lifespan

Answer 2

ab 9 days

Question 3

how thrombocytes stain

Answer 3

light purple-blue

Question 4

function of thrombocytes

Answer 4

form clots (“platelet plug” or “hemostatic plug”)

Question 5

what attracts thrombocytes to the site of a vessel tear

Answer 5

chemicals released from blood vessel wall

Question 6

what is Fibrin

Answer 6

proteins in blood form fibrin, binds platelets together to seal blood clot

Question 7

normal canine thrombocyte count

Answer 7

200,000-500,000/ul

Question 8

possible causes of thrombocytopenia

Answer 8

aplastic anemia, some bacterial and viral diseases, autoimmune diseases (platelets destroyed by body), massive hemorrage

Question 9

what is aplastic anemia, what may cause?

Answer 9

destruction of megakaryocytes/marrow destroyed by drugs, radiation, or excessive estrogen (aplasia= no growth)

Question 10

where up to 30% of platelets are stored

Answer 10

spleen

Question 11

we may not see clinical signs of thrombocytopenia until the numbers drop below

Answer 11

50,000/ul

Question 12

clinical signs of thrombocytopenia

Answer 12

slow clotting time (excessive bleeding), unexplained bruising (aka contusion)- subcutaneous bleeding

Question 13

2 kinds of bruising/contusions

Answer 13

petechia- small pinpoint bruising (small capillaries bleeding)
ecchymoses- large area of bruising

Question 14

tests to diagnose clotting issues

Answer 14

platelet count and total protein (fibrin)

Question 15

how to count platelets indirectly

Answer 15

estimated count- while doing differential, scan 10 fields in oil, count all/10= average

Question 16

canine platelet estimated count average

Answer 16

7-10/ hpf (high powered field)

Question 17

what is considered a low estimated platelet count in canine

Answer 17

> 5 suggests problem, >3 suggests thrombocytopenia (should then do a direct count)

Question 18

thrombocytosis may indicate

Answer 18

response to a problem such as trauma, disease, hemmorage (cause the release)

Question 19

how thrombocyte production is controlled

Answer 19

by demand- low circulating number-> bone marrow increases number of megakaryocytes-> increased number of platelets (spleen also releases)

Question 20

How to do direct platelet count

Answer 20

Hemocytometer and thrombotic kit