Motor Function and ControlDescending Tracts
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2020
The motor cortex generates and controls motor commands, which are transmitted to the descending pyramidal and extrapyramidal tracts. The cerebral cortex consists of three reciprocally interconnected areas: primary motor cortex, supplementary motor cortex and premotor cortex (Figure 9.1). The primary motor cortex (Brodmann's area 4), located in the precentral sulcus, has a topographical representation of the body (motor homunculus) with the head, face and hands represented laterally and the legs and feet medially. The more complex the movement of a particular part of the body, the more motor cortex is devoted to it. The tongue, lips and hands have a much greater representation because of the complexity of their motor activity. The primary motor cortex is responsible for the control of voluntary movements.
Neuroanatomy overview
Michael Y. Wang, Andrea L. Strayer, Odette A. Harris, Cathy M. Rosenberg, Praveen V. Mummaneni in Handbook of Neurosurgery, Neurology, and Spinal Medicine for Nurses and Advanced Practice Health Professionals, 2017
The four lobes of the brain are named for the bone under which they sit and are separated by lateral and central sulci as follows: Frontal: The frontal lobe sits anterior to the central sulcus. It is responsible primarily for decision making, problem solving, and planning.Parietal: The parietal lobe sits posterior to the central sulcus. Its primary function is sensory and motor input. The sensory cortex and the motor cortex are located in the parietal lobe.Temporal: The temporal lobe is located inferior to the lateral sulcus. The primary functions of the temporal lobe are language, hearing, and memory.Occipital: The occipital lobe is located posterior to the temporal and parietal lobes. Its primary function is vision.
Nervous system
David Sturgeon in Introduction to Anatomy and Physiology for Healthcare Students, 2018
The next region of the frontal lobe is the primary motor cortex situated directly in front of the central sulcus that separates the frontal lobe from the parietal lobe (Figure 12.10). It generates nerve impulses that activate skeletal muscle and control the execution of movement on the opposite (contralateral) side of the body. The primary motor cortex is mapped so that specific areas control the movement of particular body parts. For example, foot and leg movements map to the part of the primary motor cortex closest to the midline. Parts of the body capable of a high degree of movement, such as the hands and lips, are represented by large areas of the primary motor cortex. The premotor cortex consists of a narrow strip of tissue situated between the prefrontal and primary motor cortices. It helps to anticipate and plan voluntary movement and controls learned motor skills necessary to play a musical instrument or type. It also seems to play a role in the initiation and onset of laughter in response to others laughing.
Methylphenidate-mediated motor control network enhancement in patients with traumatic brain injury
Published in Brain Injury, 2018
Charlie L. Dorer, Anne E. Manktelow, Judith Allanson, Barbara J. Sahakian, John D. Pickard, Andrew Bateman, David K. Menon, Emmanuel A. Stamatakis
The motor cortex (including the premotor cortex) plans and controls the execution of voluntary motor functions and is considered to be the major source of motor control. Cerebellar-thalamo-cortical interactions are thought to have a role in computing the pattern of muscle activation necessary in order to produce smooth co-ordinated movement (2). The cerebellum is thought to adapt movement by trial learning mechanisms, although what information is predicted or how the information is derived at the neural circuit level is still debated (3). The cerebellum also interacts with vestibular and reticular nuclei to provide bilateral postural control (4). Intact functionality of these systems provides the necessary means for efficient, goal directed movement and conversely, impaired activation of these systems results in compromised movement (5).
Transcranial Direct Current Stimulation of Motor Cortex Enhances Spike Performances of Professional Female Volleyball Players
Published in Journal of Motor Behavior, 2023
Seung-Bo Park, Doug Hyun Han, Junggi Hong, Jea-Woog Lee
In another aspect, although electrical stimulation was applied to the specific cortical area of M1 induced by tDCS in the present study, it might have affected adjacent areas, resulting in a somewhat more widespread area of target stimulation. This means that the premotor cortex, complex system of interconnected frontal lobe areas anterior to the primary motor cortex, s mainly responsible for motor functions. The upper motor neurons in the premotor cortex regulates motor behavior via extensive reciprocal connections with the primary motor cortex and axons projecting through the corticobulbar and corticospinal pathways that affect local circuit and lower motor neurons of the spinal cord and brainstem (Purves et al., 2001). In particular, the left dorsal premotor cortex activity is associated with complex motor coordination performance, meaning that tDCS has potential to improve visuomotor coordination (Pavlova et al., 2014). According to Tzvi et al. (2022), the cerebellum plays an essential role in the process of visuomotor adaptation. They noted that interaction with cortical structures, especially the premotor cortex, contributed mainly to this process. The cerebellum plays a central role in coordinating voluntary movements and motor skills including balance, coordination, and posture (Manto et al., 2012). These relationships suggest that activation of the premotor cortex and its interactions with the cerebellum could enhance the process of motor coordination by tDCS (Kwon et al., 2015; Tzvi et al., 2022).
Mirror therapy and treadmill training for patients with chronic stroke: a pilot randomized controlled trial
Published in Topics in Stroke Rehabilitation, 2019
P. Broderick, F. Horgan, C. Blake, M. Ehrensberger, D. Simpson, K. Monaghan
It is thus appropriate to hypothesize that additional mechanisms might account for the reduction in muscle tone. Following stroke, the functioning of the primary motor cortex (M1) regarding the execution of motor commands can be severely disrupted.22,53 This leads to rapid onset of unilateral paresis followed by lesion- and activity-dependent adaptive changes within the brains higher centers that are also facilitated by immobilization and disuse of the affected limbs.22,53 Spasticity and abnormal muscle tone emerge due to these successive changes.21,22 MVF has been shown to stabilize activity within ipsilesional and contralesional M1 following stroke.54 Additionally, treadmill training necessitates forced use of the paretic limb potentially reducing the repercussions of muscle contracture that can increase muscle tone symptoms and forced use may also lead to a reduction of the maladaptive activity dependent cortical reorganization that follows limb immobilization post-stroke.23,24 It is possible that the combination of mirror therapy and treadmill training serve to reduce these concomitant factors that facilitate the emergence and maintenance of increased muscle tone, resulting in its reduction.
Related Knowledge Centers
- Cerebral Cortex
- Posterior Parietal Cortex
- Premotor Cortex
- Primary Motor Cortex
- Supplementary Motor Area
- Frontal Lobe
- Primary Somatosensory Cortex
- Motor Control
- Precentral Gyrus
- Motor Planning