Flashcards in Lab Section 3 Deck (45):
what nucleus creates the anterior tubercle and what does it project from and to?
anterior nucleus of the thalamus
receives input from the mammilary bodies and projects to the cingulate gyrus
which two thalamic nuclei are involved in emotion?
anterior nucleus and dorsomedial nucleus
which two thalamic nuclei are involved in motor function? where do they receive input from and where do they project to?
Ventral anterior and ventral lateral nuclei
both receive input from the basal ganglia and cerebellum
both project to the premotor cortex and the VL projects to the precentral gyrus also
which two thalamic nuclei are involved in somatosensory function? How are they different?
VPL and VPM
VPL receives input from the body and the VPM receives input from the face
which thalamic nucleus is involved with visual perception and language?
which thalamic nucleus is involved with audition? what are its inputs and projections?
medial geniculate nucleus
input from the inferior colliculus
projects to the auditory cortex
which thalamic nucleus is involved with vision? what are its inputs and projections?
lateral geniculate nucleus
input from the optic tracts
projects to the visual cortex
which thalamic nucleus is involved with attention and arousal? where does it project to?
projects to the basal ganglia and diffusely to the cortex
when does information from the medial lemniscal system cross?
at the internal arcuate fibers in the medulla. Travels from the gracile and cuneate nuclei to the medial lemniscus
what does protopathic information travel on before it crosses the spinal cord? where does it make its first synapse?
dorsal horn of the gray matter
Where does protopathic information cross the spinal cord?
in the anterior white commissure near to where it entered the cord
where does the ALS synapse? Where does it go following that synapse?
diffusely around the brainstem but mostly in the reticular formation
goes to the VPL (mostly) and DM nuclei of the thalamus
Injury to the spinocerebellar system will cause deficits on what side?
where does the dorsal spinocerebellar tract enter the cerebellum?
through the inferior cerebellar peduncle
how does the spinocerebellar tract first travel through the CNS? where does it synapse?
via the gracile and cuneate fasciculi
synapses in Clarke's Nucleus and the Accessory Cuneate Nucleus respectively
after the first synapse, how does the body's proprioceptive information travel?
as the dorsal spinocerebellar tract
name the four nuclei of the trigeminal nerve and what types of information they are associated with.
Principal sensory nucleus- epicritic information
spinal nucleus- pontine portion is epicritic, medullary portion is protopathic
mesencephalic nucleus- proprioceptive information
motor nucleus- motor (although receives proprioceptive input for reflexes)
describe the flow of facial epicritic sensation.
CN V > Principal sensory nucleus and pontine portion of the spinal nucleus > (cross midline) > medial lemniscus > VPM of thalamus > internal capsule > S1
describe the flow of facial protopathic sensation.
CN V > descending spinal tract of V > spinal nucleus > (cross midline) > reticular formation > VPM of thalamus > internal capsule > S1
describe the flow of facial proprioceptive information.
CN V mesencephalic tract > mesencephalic nucleus of V > motor nucleus of V > reticular formation > cerebellum
describe the motor component of trigeminal
corticobulbar tract > motor nucleus of V > CN V > muscles of mastication
what does the corticobulbar tract do and what will happen with unilateral damage to it?
controls the cranial nerve nuclei
contralateral weakness-not significantly because of bilateral projections (excluding CN VII and XII)
describe the corticopontine tract.
it is a motor tract that descends from the cortex and terminates on the pontine nuclei
where do the pontine nuclei project to?
the contralateral middle cerebellar peduncle
describe the cortico-rubro-olivary circuit
the cortex projects to the red nucleus > inferior olive > cerebellum
describe the main pathway of the corticospinal tract.
cortex > internal capsule > crus cerebri > basis of the pons (corticospinal tracts) > pyramids > decussation of the pyramids > lateral corticospinal tract
what is the secondary option for the corticospinal tract?
instead of decussating, some fibers continue ipsilaterally and form the ventral corticospinal tract to supply the axial musculature
is the corticospinal tract typically damaged?
it is usually damaged in conjunction with the extrapyramidal tracts to cause marked paralysis
what pathway do the basal ganglia contribute to?
the cortex projects to the basal ganglia. information flows out of the globus pallidus to the VL and VM of the thalamus. These nuclei project back to the premotor and motorcortices
what two structures project to the VL and VM nuclei of the thalamus?
the cerebellum and the globus pallidus
what are the four major extrapyramidal pahways?
rubrospinal, vestibulospinal, tectospinal and reticulospinal
what two pathologies could lessen motor tone? how can they be distinguished?
ventral root or dorsal root disease
distinguished between by motor or sensory deficits
what is one consequence of peripheral motor neuron disease that does not occur in sensory neuron diseases?
motor neuron disease causes fasciculations and eventual muscle fiber death
what are the muscle tone and reflex characteristics for upper and lower motor neuron damage?
LMN- flaccid paralysis and hyporeflexia
UMN- at first, same as LMN but eventually developing a spastic paralysis and hyperreflexia
what is the pattern of paralysis of the face?
LMN- the whole face will droop
UMN- the forehead is spared because it receives innervation bilaterally (above the facial nucleus)
where do the bilateral projections to the forehead come from?
they come from a portion of the cingulate gyrus that has to do with emotional behavioral responses
what is the major visual pathway?
the geniculo-calcarine pathway
describe the major flow of visual information.
optic nerve> optic chiasm (some) > optic tract > Lateral geniculate nucleus > internal capsule > optic radiations> calcarine sulcus and V1
what are the three alternative endpoints for visual information?
which two areas of the midbrain are important in the pupillary light response?
the pretectal area and the Edinger Westphal nucleus
what is the role of the superior colliculus in vision?
allows rapid orientation of our eyes and body to a visual event
where are the only unilateral portions of the auditory tract?
in CN VIII and its cochlear nuclei (ventral and dorsal)
where do some second order auditory neurons synapse and what eventually carries all of the information to the inferior colliculus?
the superior olive
the lateral lemniscus
where does the lateral lemniscus terminate and where does the information go from there?
inferior colliculus> brachium of the IC > medial geniculate nucleus > internal capsule > auditory radiations > heschl's gyri