Ascending/Descending Pathways Each Subnuclei of thalamus relays information to a specific part of cerebral cortex
Primary Motor Cortex (M1) Primary Somatosensory cortex (S1) Anterior To cingulate gyrus of limbic lobe (memory/emotion)
Location Anterior to the central sulcus in the In the postcentral gyrus of parietal lobe Medial Geniculate To primary auditory cortex
precentral gyrus of the frontal lobe
Lateral Geniculate To primary visual cortex
Immediately anterior to it is the
premotor cortex (involved in Mediodorsal To prefrontal region (cognition)
planning and preparation)
Lateral (more specifically To primary somatosensory cortex
Function Voluntary movement of opposite half Receives sensation for light touch, the Ventral Posterior *This is for all somatosensory pathways (even for different
of the body proprioception, pain, temperature, and
Nucleus - posterior modalities)
vibration of opposite half of body
aspect of ventral tier)
Internal Capsule : white matter structure that contains ascending and descending axons
but the corticospinal tract makes up a large portion of it
● Location : inferomedial part of each cerebral hemisphere.
What happens if we damage the internal capsule? There is complete contralateral
paralysis (hemiplegia) due to the compaction of all motor fibers in this region
Brainstem : where the fibers decussate and enter the spinal cord
Primary Motor cortex vs Premotor Cortex
● Primary Motor cortex : produces coordinated (reaching/grasping) movements
involving the entire upper extremity
● Premotor cortex : produces movements in hand area to control fine finger
movements
Thalamus (gateway to cerebral cortex)
● Location : above the brainstem between the cerebral cortex and midbrain
● Function : relay motor and sensory signals to the cerebral cortex
Primary Motor Cortex (M1) Primary Somatosensory cortex (S1) Anterior To cingulate gyrus of limbic lobe (memory/emotion)
Location Anterior to the central sulcus in the In the postcentral gyrus of parietal lobe Medial Geniculate To primary auditory cortex
precentral gyrus of the frontal lobe
Lateral Geniculate To primary visual cortex
Immediately anterior to it is the
premotor cortex (involved in Mediodorsal To prefrontal region (cognition)
planning and preparation)
Lateral (more specifically To primary somatosensory cortex
Function Voluntary movement of opposite half Receives sensation for light touch, the Ventral Posterior *This is for all somatosensory pathways (even for different
of the body proprioception, pain, temperature, and
Nucleus - posterior modalities)
vibration of opposite half of body
aspect of ventral tier)
Internal Capsule : white matter structure that contains ascending and descending axons
but the corticospinal tract makes up a large portion of it
● Location : inferomedial part of each cerebral hemisphere.
What happens if we damage the internal capsule? There is complete contralateral
paralysis (hemiplegia) due to the compaction of all motor fibers in this region
Brainstem : where the fibers decussate and enter the spinal cord
Primary Motor cortex vs Premotor Cortex
● Primary Motor cortex : produces coordinated (reaching/grasping) movements
involving the entire upper extremity
● Premotor cortex : produces movements in hand area to control fine finger
movements
Thalamus (gateway to cerebral cortex)
● Location : above the brainstem between the cerebral cortex and midbrain
● Function : relay motor and sensory signals to the cerebral cortex
