lecture 20 Flashcards
(28 cards)
describe the difference btwn muscle spindle and muscle tendon location
muscle spindles located within muscles, muscle tendons located within skeletal muscle tendons
describe the difference btwn muscle spindle and muscle tendon detection
spindles detect change in length of muscles, while tendon detects changes in tension of the muscle
review - where is the substantia gelatinosa?
posterior dorsal horn of sc
review - where is the nucleus proprius?
posterior dorsal horn of sc, anterior to sub gel
review - where is the dorsal nucleus (Clarke’s Column)?
almost in bridge btwn two sides of sc gray matter but just lateral
list the relevant ascending pathways of the sc
- dorsal column system (cuneate fasciculus, gracile fasciculus)
- dorsal lateral fasciculus (Lissaurer’s tract)
- dorsal posterior spinocerebellar tract
- ventral spinocerebellar tract
list the relevant descending pathways of the sc
- lateral motor systems (lateral corticospinal tract, rubrospinal tract)
- medial motor systems (reticulospinal tract, vestibulospinal tract and tectospinal tract)
- anterior corticospinal tract
where do the mechanosensory pathways terminate in the sc?
posterior (dorsal) columns
where do the mechanosensory pathways cross over?
level of caudal medulla (after nucleus cuneatus)
there are 4 mechanosensory pathways, where do they go?
3 to cerebrum
1 to cerebellum
what is the convoluted mechanosensory pathway from the body to the cerebellum for?
why does this make sense?
- unconcious proprioception
- makes sense bc cerebellum is involved in coordinating precise movements and muscle tone
describe the pathway for mechanosensation from the head to the cortex
- pain, temp, touch, pressure (teeth), etc
- trigeminal nuclei –> trigeminal spinal nucleus –> trigeminal nucleus (mesencephalic and main sensory) –> trigeminal lemnciscus –> ventral posterior medial nucleus of thalamus –> primary somatic sensory cortex
trigeminal main sensory nucleus connected to?
trigeminal motor nucleus (important for descending pathways)
how is the primary somatosensory cortex organized?
somatotopicly
where does the somatosensory association cortex (posterior parietal) receive its input from?
primary and secondary somatic sensory cortices
from the posterior parietal cortex, where is information passed?
to the inferior parietal cortex
what would be the result of damage to the right side of the inferior parietal gyrus?
left spacial neglect
what would be the result of damage to the right side of the temporal-parietal junction?
left spacial neglact
why doesn’t damage to the inferior parietal gyrus or the temporal-parietal junction cause visual deficits?
patients ignore the left side of their body as well as the space it occupies
what would be the result of stimulating the right side of the angular gyrus? explain.
out-of-body experience
(right angular gyrus integrates visual information - sight of your body and the information that creates the minds representation of the body, thus, representation in our brain can be dissociated from our real body)
describe left side neglect
- the left parietal cortex only oversees attention to the right side of the bosy and the space it occupies
- the right parietal cortex mediates attention to both sides
- lesion to the right parietal cortex gives rise to contralateral neglect because the left side has lost its only surveillance
what would be the result of stimulating the left side of the angular gyrus?
sensation of a shadowy person lurking right behind them
where do the pain/temperature pathways terminate in the sc?
dorsal horn –> spinothalamic tract (anterolateral system)
what are the main tracts in the anterolateral pathway?
- spinothalamic
- spinoreticular
- spinomesencephalic
