2-Minute Neuroscience: Motor Cortex

Summary

This video explains the motor cortex, a key area of the brain involved in voluntary movement. Located in the frontal lobe, it is divided into the primary motor cortex and nonprimary motor cortex. The primary motor cortex controls body movements through a 'motor map,' with signals traveling via the corticospinal and corticobulbar tracts. The nonprimary motor cortex includes the supplementary motor cortex, which aids in movement sequencing and skill development, and the premotor cortex, which helps plan movements. This concise overview covers the motor cortex’s structure, functions, and pathways essential for motor control.

Takeaways

• 😀 The motor cortex is located in the frontal lobe and is involved in voluntary movement.
• 😀 The motor cortex is divided into two major regions: the primary motor cortex and the nonprimary motor cortex.
• 😀 The primary motor cortex is located in the precentral gyrus, just anterior to the central sulcus.
• 😀 The primary motor cortex contains a motor map, with different parts controlling movement in different body parts.
• 😀 Neurons from the primary motor cortex travel through two major motor pathways: the corticospinal and corticobulbar tracts.
• 😀 The corticospinal tract carries movement-related signals to the spinal cord, controlling body movements.
• 😀 The corticobulbar tract carries movement-related signals to the brainstem, controlling head, neck, and face movements.
• 😀 The nonprimary motor cortex consists of two regions: the supplementary motor cortex and the premotor cortex.
• 😀 The supplementary motor cortex may help with the execution of movement sequences, motor skills, and selecting movements based on sensory information.
• 😀 The premotor cortex plays a role in planning movements and contributes about 30% of neurons to the corticospinal tract.

Q & A

What is the motor cortex?

The motor cortex is a region in the frontal lobe of the brain that is responsible for controlling voluntary movements.

Where is the motor cortex located in the brain?

The motor cortex is located anterior (in front) of the central sulcus in the frontal lobe.

What are the two major regions of the motor cortex?

The two major regions of the motor cortex are the primary motor cortex and the nonprimary motor cortex.

What is the primary motor cortex, and where is it located?

The primary motor cortex is a strip of cortex located in the precentral gyrus, just anterior to the central sulcus, and it controls voluntary movements of different parts of the body.

What is a motor map in the primary motor cortex?

A motor map in the primary motor cortex is a representation where different areas of the cortex correspond to the motor control of specific body parts.

What are the corticospinal and corticobulbar tracts?

The corticospinal tract carries movement signals to the spinal cord to control body movements, while the corticobulbar tract carries signals to the brainstem to control movements of the head, neck, and face.

What is the function of the nonprimary motor cortex?

The nonprimary motor cortex is involved in planning and coordinating movements, including the execution of movement sequences and the attainment of motor skills.

What are the two main regions of the nonprimary motor cortex?

The two main regions of the nonprimary motor cortex are the supplementary motor cortex and the premotor cortex.

What role does the supplementary motor cortex play?

The supplementary motor cortex is thought to be involved in executing sequences of movements, attaining motor skills, and selecting movements based on sensory information.

How does the premotor cortex contribute to movement?

The premotor cortex contributes to movement by being more active during the planning phase of movements, and it contributes about 30% of the neurons that enter the corticospinal tract.