Neuroanatomy 2 (ascending and descending tracts) Flashcards
how many column does the white matter of the spinal cord have (between the H shaped grey matter)
4
posterior column
anterior column
2 lateral columns
what is the H shaped grey matter in the spinal cord divided into
Horns
2 posterior
2 anterior
what is different in spinal segments T1-L2
there is a lateral horn which contains sympathetic neurones
sympathetic neruons exit at T1-L2
what arteries supply blood to the spinal cord
Longitudinal arteries
Segmental arteries
Radicular arteries
what are the 3 longitudinal arteries supplying the spinal cord
Anterior spinal artery
2 posterior spinal arteries
what are the segmental arteries derived from
vertebral, intercostal and lumbar arteries
where do radicular arteries travel
along the posterior and anterior roots
how is blood drained from the spinal cord
longitudinal and segmental veins
what is the epidural space
space between the dura mater and the bone containing adipose tissue and the anterior and posterior epidural Venus plexuses
where is the primary somatosensory cortex (first place we feel things lol)
Post-central gyrus cortex
sensory - deal with ur feelings AFTER lol
what happens to white matter as you descend the spinal cord
it becomes less
how do somatic sensory neruons get to the post-central gyrus
ascends via spinal cord
what makes up the dorsal column
fascicles gracilis
fascicles cuneatus
is the dorsal column ascending or descending
ascending
what does the dorsal column/medial lemniscus system do
transmits fine touch information and proprioception up the spinal cord to the brain
where do the sensory info in the dorsal column travel
Through the medulla (crosses over at medulla) synapsing in the nucleus gracilis and nucleus cuneas
up through the pons via the medial lemniscus
through the medulla via the medial meniscus
into the thalamus where they synapse again then up into the sensory cortex
how many neurons are involved in the dorsal column
3
what nerves ascend via the spinothalamic tract
pain
temperature
deep pressure
how is information passed up through the spinothalamic tract to the sensory cortex
synapse 1 at the cervical or lumbar cord CROSSES straight away
travels up through the medulla and pons into the midbrain
synapses in the thalamus
then goes onto the sensory cortex
where is the primary motor cortex
the precentral gyrus
why does the right motor cortex control muscles on the left side of the body
because motor fibres cross the midline
what are the ascending tracts
the dorsal column
the spinothalamic tract
what are the descending tracts
Corticospinal/Pyramidal tract
Tectospinal tract
Reticulospinal tract
Vestibulospinal tract
what travels down the corticospinal tract
fine, precise movement, particularly of distal limb muscles eg. digits
why is the corticospinal tract also called the pyramidal
because the tract forms visible ridges on the anterior surface of the medulla
where do nerves cross over in the corticospinal tract
straight away at level of entry
what are the motor systems outside of the pyramidal tract referred to as
extrapyramidal system
what is the tectospinal tract
tract mediating reflex head and neck movement due to visual stimuli
stays in cervical segments
what is the internal capsule
white matter area where lots of modalities pass through
what is the reticulospinal tract
fibres originate in pons and facilitate extensor movements and inhibit flexor movements
vestibulospinal tract
receives info from the vestibular apparatus and gives balance lol
what is brown-sequard’s syndrome
hemisection of the spinal cord - depending on where different tracts cross determines where there is weakness and loss of sensation ect
cranial nerve and motor system on one side
reflexes give ipsilateral hyperflexia and extensor plantar reflex
ipsilateral loss of vibratory sensory and proprioception and contralateral loss of temperature
