week 6 lectures (central pathways) Flashcards
what are 4 components of central pathways?
cortex
thalamus
basal ganglia
cerebellum
what lobe does the calcarine sulcus define the boundary of?
the occipital lobe
where are connections to the cerebellum rooted in?
the pontine nuclei
what is the function of the thalamus?
acts as a hub for information flow
relays sensory information to the appropriate cortical regions
what parts of the brain modulate the thalamus?
the basal ganglia
the cerebellum
whats a potential theory for the cause of synestesia
the thalamus may relay information to the wrong cortical areas
are the output neurons of the thalamus exitatory or inhibitory?
excitatory
how and why does the thalamus shut down information flow?
inhibitory interneurons in the thalamus have powerful inhibitory effect on transmission
this is useful during sleep as the activity of the cortex is reduced
its also useful to shut down visual information everytime your eyes make rapid movements so we dont get a blurred visual flow
how does the thalamus act as in information hub?
- it recieves information from the cortex
- so there is reciprocal, point to point connections:
thalamocortical
corticothalamic
what two white matter tracts is the thalamus involved in?
the corona radiata
the internal capsule
what is the function of the basal ganglia?
it modulates thalamus responses
basal ganglia are spontaneously active and inhibitory neurons
an increased output from the basal ganglia makes the thalamus less responsive to the cortex
this means that cortical activity is reduced
it is involved in REWARD and MOTIVATION
it is implicated in parkinsons diseaese and depression
what is the function of the cerebellum?
It modulates the thalamus by exciting it
it has spontaneously active excitatory neurons
cerebellar output is modulated by cortical, sensory and proprioceptive data
it is involved in TIMING and PRECISION
it is implicated in motor coordination disorders and autistic spectrum disorder
alcohol has a profound effect on the cerebellum and leads to clumsiness
what are three cortical output tracts by the thalamus?
corticospinal- to the body
corticobulbar- tothe hindbrain. involved in moving muscles of the face, speech etc.
corticopontine- from the frontal cortex to the pontine nuclei and then to the cerebellum
