Final answer:
Meissner corpuscles in the fingertips allow for the discrimination of fine detail when holding and feeling objects, like the texture of a pen.
Step-by-step explanation:
When holding a pen, you can feel the fine detail with Meissner corpuscles in your fingertips. These specialized mechanoreceptors are sensitive to light touch and are a primary component of the tactile sensing system in human skin, especially in areas like the fingertips where touch discrimination is crucial. Whether using a pen, a rapidograph pen with various metal point thicknesses for technical drawing, soft-pointed brushes for ink drawing, or even feeling the difference between pencil grades like HB or B, the Meissner corpuscles help us discern subtle textures and grip objects with precision.