The Brain’s Structure and Connectivity
This lecture focused on the development of the brain’s connectivity between its major parts.
Key Points:
- The telencephalon, initially two separate hemispheres, expands and covers the other brain regions.
- In an adult brain, two important structures bridge these regions:
- Corpus callosum: Connects the two hemispheres, enabling communication between them.
- Internal capsules: Connect the telencephalon to the diencephalon. They carry crucial information, including motor information to the muscles.
Brain Connectivity:
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Initially, the hemispheres are separate structures.
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The corpus callosum develops later, allowing communication between the hemispheres.
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The internal capsules connect the telencephalon (cerebral cortex) to the diencephalon. They carry information, including motor signals that control muscles on the opposite side of the body.
(not a mid sagittal cut, it is para sagittal cut)
Brain Regions:
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Spinal cord: Carries signals between the brain and the body.
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Hindbrain: Includes the pons, medulla, and cerebellum. Involved in basic functions like breathing and heart rate.
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Midbrain: Relays sensory and motor information.
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Diencephalon: Contains structures like the thalamus, which relays sensory information to the cortex.
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Telencephalon: Makes up the cerebrum, the largest part of the brain. The outer layer is the cerebral cortex, responsible for higher functions like thinking and memory.
Additional Notes:
- The space in the center of the brain (ventricles) contains cerebrospinal fluid and is not brain tissue.
- A midsagittal cut divides the brain in half along the midline.
- A parasagittal cut is similar to a midsagittal cut but slightly off-center.
- A horizontal cut divides the brain parallel to the ground.
Final Diagram:
The lecture concludes by introducing a simplified brain diagram that will be used throughout the course. This diagram shows the major brain regions and their connections via the corpus callosum and internal capsules.
