🧠 “A Tiny Lesion, Huge Consequences: The Internal Capsule Explained”
Hello Steemians! 💫
As part of my studies in neuroanatomy, today I learned about a very important structure in the brain called the Internal Capsule. I thought it would be nice to share it here in simple words so others can also learn.
📍 What is the Internal Capsule?
The internal capsule is a white matter structure in the brain. It contains important sensory and motor fibers that connect different parts of the brain with the body.
It looks V-shaped when seen in cross-section.
The concavity is towards the outside (lateral side).
Motor fibers (that control movement) are converging.
Sensory fibers (that carry touch, pain, temperature) are diverging.
🧩 Boundaries
Medial boundary: Caudate nucleus
Lateral boundary: Lentiform nucleus
🏗️ Parts of the Internal Capsule
- Anterior Limb – between caudate nucleus and anterior lentiform nucleus
Genu (G-E-N-U) – the bent part between anterior and posterior limb
Posterior Limb – between thalamus and lentiform nucleus
- Retrolenticular Segment – behind the lentiform nucleus
- Sublenticular Segment – below the lentiform nucleus
🔌 Important Connections
Anterior limb → connected to frontopontine fibers (frontal lobe → pons)
Genu → carries motor fibers for the face
Posterior limb → carries corticospinal tract (motor for body) and sensory fibers (touch, pain, temperature)
Fibers going upward → form the corona radiata
Fibers going downward → form the crus cerebri
🌟 Why It’s Important
The internal capsule is like a superhighway of the brain. If it gets damaged (for example, in a stroke), it can cause serious problems such as paralysis or loss of sensation, because all these critical fibers pass through it.
💭 Question for You:
Do you enjoy learning about how the brain works? If yes, would you like me to share more of my neuroanatomy lessons here on Steemit?