Which of the following veins or dural venous sinuses does NOT drain directly into the cavernous sinus?

Step 1: Analyze Question 128.
The question asks which of the listed veins or dural venous sinuses does not drain directly into the cavernous sinus.

• a) Ophthalmic veins: The superior and inferior ophthalmic veins drain directly into the cavernous sinus.
• b) Superior petrosal sinus: This sinus drains from the cavernous sinus posteriorly into the transverse sinus. It is an outflow, not an inflow.
• c) Superior sagittal sinus: This sinus runs along the superior margin of the falx cerebri and drains into the confluence of sinuses, which then drains into the transverse sinuses. It does not drain directly into the cavernous sinus, nor is it a direct outflow.
• d) Pterygoid plexus of veins: This plexus communicates with the cavernous sinus via emissary veins, allowing blood to drain from the plexus into the cavernous sinus.
• e) Inferior petrosal sinus: This sinus drains from the cavernous sinus inferiorly into the internal jugular vein. It is an outflow, not an inflow.

The superior sagittal sinus has no direct connection to the cavernous sinus, making it the correct exception.

The correct answer is c).

$$\boxed{\text{c) superior sagittal sinus}}$$