The arachnoid mater forms granulations that project into the dural venous sinuses for CSF absorption. Where are these arachnoid granulations most concentrated?

• A Inferior sagittal sinus
• B Cavernous sinus
• C Transverse sinus
• D Superior sagittal sinus ✓

Explanation

Arachnoid granulations (Pacchionian bodies) are most numerous along the superior sagittal sinus, especially in the lateral lacunae. They increase with age and may form macroscopic depressions on the inner calvarium near the vertex. They function as one-way valves allowing CSF to enter venous blood when CSF pressure exceeds venous pressure. The inferior sagittal, transverse, and cavernous sinuses are not the primary sites of CSF absorption.

Reference: Gray's Anatomy, 42nd ed.

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