Questions: The primary motor area (cortex) send signals to which of following that ultimately results in muscle contractions? Cerebellum and temporal lobe Spinal cord and limbic system Primary visual area Brainstem and spinal cord

The answer is the last one: Brainstem and spinal cord.

Explanation for each option:

1. Cerebellum and temporal lobe: The cerebellum is involved in coordination and precision of movements, but it does not directly receive signals from the primary motor cortex to initiate muscle contractions. The temporal lobe is primarily associated with processing auditory information and is not involved in motor control.

2. Spinal cord and limbic system: The spinal cord is indeed involved in transmitting motor signals from the brain to the muscles, but the limbic system is primarily associated with emotions and memory, not motor control.

3. Primary visual area: This area is involved in processing visual information and is not related to motor control or muscle contractions.

4. Brainstem and spinal cord: The primary motor cortex sends signals through the brainstem and spinal cord to initiate and control voluntary muscle movements. The brainstem acts as a relay center, and the spinal cord transmits these signals to the peripheral nerves that control muscles.

In summary, the primary motor cortex sends signals to the brainstem and spinal cord, which are directly involved in the process of muscle contraction.