Anterior horn of lateral ventricle is closed anteriorly by
**Core Concept**
The anterior horn of the lateral ventricle is a part of the cerebral ventricular system, which is a complex network of fluid-filled spaces within the brain. The lateral ventricles are divided into four horns (anterior, posterior, inferior, and superior) and are surrounded by gray matter.
**Why the Correct Answer is Right**
The anterior horn of the lateral ventricle is closed anteriorly by the **column of the fornix**, a bundle of nerve fibers that plays a crucial role in memory and learning. The fornix is composed of the hippocampal commissure and the fornical fibers, which connect the hippocampus to the mammillary bodies. The column of the fornix forms a boundary between the anterior horn of the lateral ventricle and the anterior part of the third ventricle.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the **column of the fornix** specifically closes the anterior horn, not the posterior horn.
* **Option B:** This option is incorrect because the **thalamostriate vein** is a structure that drains blood from the thalamus and striatum, but it does not form the anterior boundary of the anterior horn.
* **Option C:** This option is incorrect because the **choroid plexus** is a structure that produces cerebrospinal fluid, but it does not form the anterior boundary of the anterior horn.
* **Option D:** This option is incorrect because the **internal capsule** is a structure that contains nerve fibers that connect different parts of the brain, but it does not form the anterior boundary of the anterior horn.
**Clinical Pearl / High-Yield Fact**
The column of the fornix is a key structure in the brain that plays a crucial role in memory and learning. Damage to this structure can lead to memory impairments and other cognitive deficits.
**Correct Answer:** C. Choroid plexus