Lesson 3 ·Class 10 · The Nervous System · Label Lab
The Brain
Three parts, three very different jobs.
Tap any part of the diagram to learn its name and its job. Try: The impulse to walk starts in the cerebrum; the cerebellum only times and coordinates the muscles. That is why a drunk person walks clumsily.
Free play — explore the diagram, or switch to "Label it yourself" and place every label. Switch to when you're ready to test yourself.
In the brain the gray matter lies outside and the white matter inside. In the spinal cord the arrangement is exactly reversed. That reversal is a favourite assertion-reason question.
What this lesson covers
What you do
- The impulse to walk starts in the cerebrum; the cerebellum only times and coordinates the muscles. That is why a drunk person walks clumsily.
- Three meninges, the dura mater, arachnoid and pia mater, with cerebrospinal fluid between them, cushion both the brain and the spinal cord.
The parts you label
- Cerebrum — The largest part of the brain, in two hemispheres joined by the corpus callosum. Its folded gray cortex, with ridges called gyri and grooves called sulci, is the seat of intelligence, memory, consciousness and will power, and it controls all voluntary actions.
- Cerebellum — The little brain, lying at the base under the cerebrum. It has no convolutions, only furrows, and its job is to maintain the balance of the body and coordinate muscular activity.
- Medulla oblongata — The lowest, roughly triangular part at the base of the skull. It controls the activities of the internal organs: heartbeat, breathing and peristalsis. Injury here generally results in death.
- Spinal cord — Continues behind the medulla down the neural canal of the vertebrae to the second lumbar vertebra. It handles reflexes below the neck and conducts impulses to and from the brain.
Challenges to clear
- Tap the part that keeps your heart beating without you thinking about it.
- Tap the part that keeps you balanced while you walk.
- Label the whole brain.
Hint
In the brain the gray matter lies outside and the white matter inside. In the spinal cord the arrangement is exactly reversed. That reversal is a favourite assertion-reason question.