platelets

Question 1

no. of platelets produced in a single megakaryocyte

Answer 1

2000-4000

Question 2

how many days can platelets survive in the circulation?

Answer 2

8-9 days

Question 3

ligands of collagen

Answer 3

GPVI and GPIa/IIa

Question 4

VWF ligand

Answer 4

GPIb/IX/V

Question 5

Fibrinogen ligand

Answer 5

GPIIb/IIIa

Question 6

sequesters calcium for activating platelets

Answer 6

Dense tubular system

Question 7

secretes a-granule contents upon platelet activation

Answer 7

surface connected canalicular system (SCCS)

Question 8

identify the granule:

• 50-80 per platelet
• stains gray
• fuse with SCCS for secretion
• in adhesion + aggregation

Answer 8

alpha granules

Question 9

identify the granule:

• 2-7 per platelet
• stains black
• directly released

Answer 9

dense granules

Question 10

platelet disorder:

• GPIIb/IIIa (aggregation)
• on populations of consanguinity
• normal aggregation to ristocetin

Answer 10

glanzmann thrombasthenia

Question 11

platelet disorder:

• GPIb/IX/V (adhesion)
• defective aggregation to ristocetin
• giant platelets (high MPV)

Answer 11

Bernard Soulier Syndrome

Question 12

triad of wiskott-aldrich syndrome

Answer 12

1. immune deficiency
2. eczema
3. thrombocytopenia

Question 13

dense granule deficiency characterized by tyrosinase-positive oculocutaneous albinism

defective lysosomal function

Answer 13

Hermansky-pudlak syndrome

Question 14

dense granule deficiency characterized by partial oculocutaneous albinism

with severe immunologic and neurologic dysfunction

Answer 14

Chediak-Higashi Syndrome

Question 15

dense granule deficiency with defective T cell function

Answer 15

Wiskott-Aldrich Syndrome