Question

Identify the structure marked by the red arrow in the given image.

• A. Great vein of Galen
• B. Pineal gland
• C. Fornix
• D. Falx cerebri

Hint:

The C-shaped tract from hippocampus to mammillary bodies is the fornix.

Answer 1

The Correct Option is C

Step 1: The arrow points to the fornix, the main efferent (output) tract of the hippocampus and an important part of the limbic system.
Step 2: The fornix is a curvilinear, roughly C-shaped bundle of white matter. It extends from the hippocampus to the mammillary bodies of the hypothalamus and the anterior nuclei of the thalamus.
Step 3: Hippocampal fibres begin as the alveus, which forms the fimbria; the fimbria thickens and splits off as the crus of the fornix. The fornix has four parts: crura, commissure, body, and columns (anterior pillars).
Step 4: The great vein of Galen is a venous channel, the pineal gland is a midline endocrine body, and the falx cerebri is a dural fold; none matches this C-shaped white matter tract, so the answer is the fornix.