Internal Capsule

Hinzugefügt: 2026-05-07

[00:00:00]Let's try and identify the internal capsule of the brain. So, for this, what we'll do is we'll take the transverse section of the brain, one cerebral hemisphere, we'll split it open.

[00:00:11]Now, let's see if we can identify the internal capsule in this specimen. So, what we have here is this is the caudate nucleus. Here, we have the lentiform nucleus, and here we have the thalamus.

[00:00:24]The same on this side. These are the thalami. This is the lentiform nucleus, and this is the caudate nucleus. In between these, can you see this? This is the bundle of white matter which is referred to as the internal capsule, the most prominent and the most important projection fiber seen in the cerebral hemisphere. The parts of the internal capsule, this is the anterior limb.

[00:00:46]Here, we have the genu. This is the posterior limb. Remember, we have the sublentiform part which passes deep to the lentiform nucleus into the temporal lobe. Then, we have retro-lentiform part which will pass posterior to the lentiform nucleus. What about the types of fibers present in this? Remember, the anterior limb of the internal capsule contains frontopontine fibers. The genu contain corticobulbar fibers for the cranial nerves of the head and neck region. The corticospinal fibers are located in the posterior limb. Upper limb being represented anteriorly, trunk in the middle, and lower limb on the posterior aspect. What about the fibers present in the sublentiform part and the retro-lentiform part? The sublentiform part contains the auditory radiation.

[00:01:35]The retro-lentiform part concerns with the optic radiation. These are some of the major fibers present in the internal capsule.