The Cerebral Hemispheres Control Muscle Movements via Motor Neurons
Definition
Cerebral hemispheres
The cerebral hemispheres are the largest part of the brain, responsible for higher-order functions like decision-making, memory, and voluntary movement.
- The cerebral hemispheres are the largest part of the brain, responsible for higher-order functions like decision-making, memory, and voluntary movement.
- Within the cerebral hemispheres lies the primary motor cortex, a specialized region that initiates and controls muscle movements.
- When you decide to move, the primary motor cortex sends signals to motor neurons that connect to your muscles.
- The primary motor cortex is organized like a map, with different areas controlling specific body parts.
- This map is called the motor homunculus.
How Motor Neurons Transmit Signals
Definition
Motor neurons
Motor neurons are the messengers that carry instructions from the brain to the muscles.
- The process begins in the grey matter of the cerebral hemispheres, where motor neurons receive signals from the primary motor cortex.
- These neurons have long extensions called axons that transmit electrical impulses.
- The axons travel down the spinal cord, where they connect with a second motor neuron.
- This second neuron’s axon extends to the target muscle, forming a synapse with muscle fibers.
Motor neurons are part of the efferent pathway, meaning they carry signals away from the central nervous system to effectors like muscles or glands.
