The extrapyramidal tracts all originate in the brainstem and do not pass through the pyramids.Contrast this to the corticospinal tract were the cerebral cortex connects to spinal motor neurons, and controls movement of the torso, upper and lower limbs.Įxtrapyramidal Tracts The muscles of the face, head and neck are controlled by the corticobulbar system, which terminates on motor neurons within brainstem motor nuclei. The corticobulbar tract is composed of the upper motor neurons of the cranial nerves. According to Harvey (2008), the cervical upper motor neurons are centrally located within the corticospinal tract while the lumbar and sacral neurons are peripherally located, which explains neurological patterns of loss seen with certain types of incomplete spinal cord injuries where the peripheral rim of the spinal cord is undamaged.Ĭorticobulbar Tract Most of the fibers, approximately 85%, cross the midline in the decussation of the pyramids in the brain stem and then descend through the spinal cord in the lateral corticospinal tract, while the other 15% cross within the spinal cord at the level they terminate and are carried within the medial corticospinal tract. Its projections are primarily contralateral and have a strong influence on the activity of groups of spinal motoneurones, which innervate distal muscles of the hands and feet. Primary motor cortex is the main source of input to this tract, but the premotor and supplementary motor cortex also contribute fibres. Also called the pyramidal tract as it is the only point where all the fibres are collected together without contamination by other fibre tracts in the medullary pyramids of the brain stem. They can be divided into two tracts.Ĭorticospinal Tract Ĭarries information from the cerebral cortex to the spinal cord. The pyramidal tracts are responsible for the conscious, voluntary control of the body and face muscles. The pyramidal tracts are named as such due to their course through the pyramids of the medulla oblongata. Extrapyramidal: unconscious, reflexive or responsive control of muscles from various brainstem structures to postural or anti-gravity muscles.Pyramidal: conscious control of muscles from the cerebral cortex to the muscles of the body and face and.These functional groups contain several anatomical tracts, one for each side of the body: These motor tracts can be grouped functionally into Extrapyramidal and Pyramidal tracts

Some of these are under conscious control and others under unconscious, reflexive or responsive control. There are many motor tracts in the spinal cord. anterior and posterior spinocerebellar and cuneocerebellar tracts ĭescending Motor Pathways There are three spinocerebellar tracts, viz. The cell bodies of the primary sensory neurons that bring this information from such receptors to the spinal cord are located in the dorsal root ganglia. Spinocerebellar Tract: Carry unconscious proprioceptive information gleaned from muscle spindles, Golgi tendon organs, and joint capsules to the cerebellum.Conveys proprioception, light touch and vibration.

In the spinal cord, this pathway travels in the dorsal column, and in the brainstem, it is transmitted through the medial lemniscus hence the name dorsal column-medial lemniscus pathway. the neural pathways by which sensory information from the peripheral nerves is transmitted to the cerebral cortex. Dorsal Column Medial Lemniscal Pathway: The dorsal column pathway is one of the ascending tracts i.e.The lateral spinothalamic tract carries information about pain and temperature, and the anterior spinothalamic tract carries information about crude touch. This pathway comprises of three neutron sets and forms part of the somatosensory system. The spinothalamic tracts: The spinothalamic tract, one of the most important pathways of the nervous system, lies anteriolaterally to the ventral horn of the spinal grey matter.

In humans the major sensory pathways include: There are many sensory tracts and pathways carrying different types of sensory information from the periphery to the cerebral cortex. Located in the white matter of the spinal cord, the ascending sensory tracts arise from either the the cells of the spinal ganglia or the intrinsic neurons within the grey matter that receive primary sensory input. Information detected by sensory receptors in the periphery is transmitted along ascending neural tracts in the spinal cord. The spinal cord, basically a highway for nerves, streamlines sensory and motor signals to the brain and the body.

Somatic nervous system pathway