In thromboasthenia there is a defect in -
Platelet adhesion

Platelet adhesion refers to the binding of platelets to subendothelial matrix.
Platelet membrane glycoprotein Ib - IX is essential for platelet adhesion to subendothelial matrix.

Platelet aggregation

Platelet aggregation refers to adherence of platelets to one another.
Platelet membrane glycoprotein IIb - IIIa helps in aggregation.

Congenital dysfunction of platelet
1.  Bernard-Soulier syndrome

Defect in platelet adhesion due to inherited deficiency of glycoprotein Ib - IX.

2. Glanzmann's thrombasthenia

Defect in platelet aggregation due to inherited deficiency of glycoprotein IIb - IIIa.
Platelet aggregation
Platelet adhesion
Decreased ADP release
Disordered platelet secretion