All tracts in CNS

Dorsal Column–Medial Lemniscus Pathway (DCML)

• Originates in dorsal root ganglia (Aβ fibers);

• decussates in the medulla via internal arcuate fibers;

• ascends through fasciculus gracilis and cuneatus to nuclei gracilis/cuneatus, then via medial lemniscus to the thalamus (VPL); conveys fine touch, vibration, and proprioception.

Spinothalamic Tract (Anterolateral System)

• Originates in dorsal horn neurons (lamina I–V);

• decussates in spinal cord (anterior white commissure);

• ascends to thalamus (VPL) and somatosensory cortex;

• conveys pain, temperature, and crude touch.

Spinoreticular Tract

• Originates in dorsal horn;

• partially decussates in spinal cord;

• ascends to reticular formation and intralaminar thalamic nuclei;

• mediates arousal and emotional aspects of pain.

Spinomesencephalic Tract

• Originates in dorsal horn;

• decussates in spinal cord; ascends to periaqueductal gray and superior colliculus;

• functions in pain modulation and orienting reflexes.

Posterior Spinocerebellar Tract

• Originates in Clarke’s column (T1–L2);

• ascends ipsilaterally to cerebellum via inferior cerebellar peduncle;

• conveys unconscious proprioception from lower limbs.

Anterior Spinocerebellar Tract

• Originates in spinal border cells;

• double decussation in spinal cord and cerebellum;

• ascends to cerebellum via superior cerebellar peduncle;

• conveys unconscious proprioception from lower limbs.

Cuneocerebellar Tract

• Originates in accessory cuneate nucleus of the medulla;

• ascends ipsilaterally to cerebellum via inferior cerebellar peduncle;

• conveys unconscious proprioception from upper limbs.

Corticospinal Tract

• Originates in motor cortex (precentral gyrus);

• descends through internal capsule, cerebral peduncle, and medulla; 85–90% decussate at medullary pyramids forming the lateral corticospinal tract;

• controls voluntary limb and trunk movements.

Corticobulbar Tract

• Originates in face area of motor cortex; descends through internal capsule to cranial nerve nuclei III–VII and IX–XII;

• controls voluntary movement of face, tongue, and jaw muscles.*

Rubrospinal Tract

• Originates in red nucleus of the midbrain;

• decussates in ventral tegmentum;

• facilitates flexor tone and inhibits extensors, mainly in the upper limbs.

Pontine (Medial) Reticulospinal Tract

• Originates in pontine reticular formation;

• descends ipsilaterally;

• facilitates extensor tone and posture.*

Medullary (Lateral) Reticulospinal Tract

• Originates in medullary reticular formation;

• descends bilaterally;

• inhibits extensor tone and modulates voluntary movement.*

Lateral Vestibulospinal Tract

• Originates in lateral vestibular nucleus;

• descends ipsilaterally;

• maintains balance and posture by facilitating extensor tone.

Medial Vestibulospinal Tract

• Originates in medial vestibular nucleus;

• descends bilaterally;

• controls head and neck position for vestibulo-collic reflexes.

Tectospinal Tract

• Originates in superior colliculus (midbrain);

• decussates in dorsal tegmentum;

• mediates reflex turning of head and eyes toward visual or auditory stimuli.*

Olivospinal Tract

• Originates in inferior olivary nucleus (medulla);

• modulates motor activity through cerebellar feedback circuits.

Corticopontocerebellar Tract

• Originates in cerebral cortex;

• synapses in pontine nuclei; crosses to opposite side via middle cerebellar peduncle;

• conveys intended motor plan to cerebellum.*

Olivocerebellar Tract

• Originates in inferior olive;

• crosses midline and enters cerebellum via inferior cerebellar peduncle;

• important for motor learning and coordination.*

Vestibulocerebellar Tract

• Originates from vestibular nuclei and nerve;

• projects to flocculonodular lobe of cerebellum;

• maintains balance and coordinates eye movements.*

Reticulocerebellar Tract

• Originates in reticular formation;

• projects bilaterally to cerebellum;

• integrates posture and muscle tone control.*

Cerebellorubral Tract

• Originates in interposed nuclei of cerebellum;

• projects to red nucleus;

• coordinates cerebellar output with motor activity.*

Cerebellothalamic Tract

• Originates in dentate nucleus;

• projects to ventral lateral thalamic nucleus;

• transmits cerebellar output to motor cortex for movement coordination.*

Cerebellovestibular Tract

• Originates in fastigial nucleus;

• projects to vestibular nuclei;

• maintains equilibrium and posture.*

Dorsal Longitudinal Fasciculus

• Originates in hypothalamus;

• descends to parasympathetic and sympathetic nuclei in brainstem and spinal cord;

• regulates visceral and autonomic functions.*

Medial Forebrain Bundle

• Originates in olfactory, septal, hypothalamic, and midbrain nuclei;

• interconnects limbic and autonomic centers;

• regulates reward, motivation, and visceral responses.*

Hypothalamospinal Tract

• Originates in posterior hypothalamus;

• descends to intermediolateral cell column (T1–L2);

• mediates sympathetic responses such as pupil dilation and vasomotor tone.*

Solitariospinal Tract

• Originates in nucleus tractus solitarius (medulla);

• integrates visceral sensory input with autonomic reflex pathways.*