Somatosensory Pathways Flashcards
Which four sensory modalities does the Anterolateral Sytem relay?
Pain
Temperature
Non-discriminative touch
Pressure
Which three sensory modalities do the Dorsal Columns relay?
Tactile sense
Vibratory sense
Positional sense
Which sensory modalities do the somatosensory pathways to the cerebellum relay?
Proprioception
Name the five Anterolateral systems?
Spinohypothalamic tract Spinotectal tract Spinomesencephalic tract Spinoreticular tract Spinothalamic tract
Name the two Dorsal columns?
Fasiculus Cuniatus - lateral
Fasiculus Gracilis - medial
Name the three Somatosensory pathways to the cerebellum?
Rostral spinocerebellar tract
Posterior spinocerebellar tract - Ipsi-lateral
Anterior spinocerebellar tract - Contra-lateral
Within the dorsal horn of the spinal cord, which laminae does Pain and Temperature synapse into?
Laminae I/II
Within the dorsal horn of the spinal cord, which laminae does proprioception synapse into?
Laminae V
Within the dorsal horn of the spinal cord, which laminae does mechanoreception synapse into?
Laminae III/IV
Which tract does ‘conscious proprioception and fine touch’ ascend within and how does it travel?
Dorsal column - Ipsilateral
Which tract does ‘pain and temperature’ ascend within and how does it travel?
Lateral spinothalamic tract - contralateral
Which tract does ‘pressure and crude touch’ ascend within and how does it travel?
Anterior spinothalamic - contralateral
How does the cerebellum receive Ipsilateral proprioception?
Fibres travelling ipsilaterally travel up the Posterior spinocerebellar tract
Fibres travelling contralaterally travel up the Anterior spinocerbellar tract and enter the cerebellum via the superior cerebellar peduncle.
Which tract is affected by sensory ataxia?
Dorsal columns
In sensory ataxia, the loss of concious proprioception leads to what symptoms?
Broad gait + stomping
Positive Rhomberg’s sign
In sensory ataxia, the loss of fine touch leads to what symptoms?
loss of two-point discrimination
Where does fine touch from the face go to?
Chief sensory nucleus of V passing contralateral beyond this point
Where does pain and temperature from the head and neck go to?
Spinal nucleus of V (continuous with dorsal horn laminae I/II), it passes contralaterally beyond this point
After fine touch fibres have crossed over inside the lower medulla, which fibre tract takes them to the thalamus?
Medial lemniscus
How does the posterior spinocerebellar tract enter the cerebellum?
Via the inferior cerebellar peduncle
Pain and temperature fibres from the thalamus go to which three places?
Insula
Primary somatosensory cortex (post-central gyrus)
Cingulate gyrus (limbic system)
