A 34-year-old man presents with a 5-day history of a painful sore on his hand. Physical examination reveals a 0.5-cm abscess on the extensor surface of the left hand that drains a thick, purulent material. Diapedesis of leukocytes into and around this patient's infected wound occurs primarily at which of the following anatomic locations?
Lymphatic capillaries Postcapillary venules Precapillary aerioles Small dermal aeries