Neuro Practical 2.1.2 Flashcards
what pathway carries discriminative touch ,proprioception, and vibration
dorsal column pathway
what pathway carries pain, crude touch, and temperature?
spinothalamic
what is the dorsal column pathway?
peripheral receptor -DRG - fasiculus cunateus/gracilis - nucelus cuneatus/ gracilis - internal arcuate fibres - medial lemniscus - VPL thalamus - internal capsule - corona radiata - post central gyrus
what is the spinothalamic pathway?
peripheral receptor - DRG - dorsal horn - ventral white commisure - spintothalamic tract of spinal cord - spinal lemnisucs - VPL thalamus - internal capsule - corona radiata - post central gyrus
- In which thalamic nucleus do neurons carrying sensory information for the head and neck synapse?
VPM
- In which thalamic nucleus do neurons carrying sensory information from the rest of the body synapse?
VPL
What areas of grey matter form the boundaries of the internal capsule on a horizontal section
caudate, lentiform, thalamus
What is the functional arrangement of fibres within the internal capsule?
anterior, genu, posterior - Anterior limb contains fibres associated with higher functions (e.g. thalamo-frontal connections). Posterior limb contains major ascending somatosensory fibres (and descending motor fibres – you will see those next time!)
Where is the primary somatosensory cortex?
The somatosensory cortex is located on the post central gyrus. This is the gyrus immediately posterior to the central sulcus, the only sulcus extending from the great longitudinal fissure to the lateral fissure.
what is the sensory homunculus?
. The feet are located on the superior / medial surface, the face is located on the inferior / lateral surface of the gyrus (refer to your lecture slides to remind you of this topographical organisation as well as the distribution of cerebral arteries across the cerebral hemispheres).
What is the principal arterial blood supply to the region of primary somatosensory cortex receiving information from the lower limb?
anterior cerebral
- What is the principal arterial blood supply to the region of primary somatosensory cortex receiving information from the head?
middle cerebral artery
where are DRGs located?
in the dural root sleeve, located in the intervertebral foramen
what is a dorsal root ganglion?
A collection of sensory neuron cell bodies outside of the CNS
C2 / C3 dermatome
C6 dermatome
T4 dermatome
T10 dermatome
L4 dermatome
c2/c3 = posterior scalp and neck
c6= anterior arm and thumb
t4 = nipple
t10 = bellybutton
l4 = knee (L3/L4)
s1 = ankle (s1/s2)
what does the spinocerebellar pathway do?
process information about posture and motor coordination
Where is general sensory information for the head and neck carried?
trigeminal nerve
where will the cell bodies of the trigeminal nerve synapse?
the trigeminal ganglion which lies outwith the brainstem, the neurones will synapse in one of the following nuclei - in order of superior to inferior
mesencephalic
cheif sensory
nucleus of spinal tract of trigeminal
What type of sensory information is associated with each of the trigeminal nerve
brainstem nuclei?
mesencephalic = proprioception
cheif sensory = touch and pressure
nucleus of the spinal trat = pain and temperature
Trigeminothalamic fibres (second order neurons) will decussate in the brain stem and then travel to the thalamus. Where in the thalamus do these fibres synapse with third order neurons?
VPM of the thalamsu
how many neurones are in the spinocerebellar pathway?
2
where do the cell bodies of the spinocerebellar pathway lie
DRG (1) and dorsal grey horn of the spinal cord (2)
what are the two principal tract relating to the spinocerebellar pathway?
dorsal spinocerebellar tract - axons do not deccussate
ventral spinocerebellar tract - axons do decussate
on what side does the spinocerebellar tract rise
the dorsal spinocerebellar tract ascend ipsilaterally and enters the cerebellum through the inferior cerebellar peduncle from the medulla
the ventral spinocerebellar tract ascends contralaterally and decussate back in the brainstem before entering the cerebellum though the superior cerebellar peduncle from the midbrain
