Brodmann area 4

Brodmann area 4 animation small

Brodmann area 4 frontal

Brodmann area 4 lateral

Brodmann area 4 medial

Gray's anatomy image 726-Brodman

Brodmann area 4 (BA4) is a region of the cerebral cortex in the brain that is involved in motor function. It is located in the precentral gyrus and is also known as the primary motor cortex. This area is responsible for the execution of voluntary movements.

Anatomy and Location

Brodmann area 4 is situated in the frontal lobe of the brain, specifically in the precentral gyrus. It is bordered by Brodmann area 6 anteriorly and Brodmann area 3 posteriorly. The primary motor cortex is characterized by a thick layer of large pyramidal cells known as Betz cells, which are crucial for motor control.

Function

The primary function of Brodmann area 4 is to generate neural impulses that control the execution of movement. These impulses are sent to the spinal cord and then to the muscles, resulting in voluntary movement. The area is somatotopically organized, meaning different parts of the area correspond to different parts of the body, a concept known as the motor homunculus.

Clinical Significance

Damage to Brodmann area 4 can result in motor deficits such as paralysis or paresis of the muscles controlled by the affected area. This can occur due to stroke, traumatic brain injury, or other neurological conditions. Understanding the function and location of BA4 is crucial for neurosurgery and neurology.

Related Areas

• Brodmann area 6: Involved in the planning of movements.
• Brodmann area 3: Part of the primary somatosensory cortex.
• Motor cortex: Includes BA4 and other areas involved in motor control.
• Precentral gyrus: The gyrus where BA4 is located.

See Also

• Cerebral cortex
• Frontal lobe
• Motor homunculus
• Pyramidal cells
• Betz cells