block 5 lecture 15 functional regions of the brain Flashcards
how many neuron pathways are there in the ascending pathways?
3 neuron pathways
what does the first order neuron do in the ascending pathway?
info from spinal cord or brain stem
what does the second order neuron do in the ascending pathway?
nucleus in CNS to thalamus
what does the third order neuron do in the ascending pathway?
thalamus to the sensory cortex
what happens in descending pathways?
upper motor neurons run from cerebrum/brainstem to the lower motor neuron in the spinal cord
what are the grooves in the brain called?
sulci
what are the lumps in the brain?
gyri
what are the boundries of the frontal lobe?
central sulcus and lateral sulcus
what is behind the central sulcus?
parietal lobe
what separates the parietal and occipital lobes?
parieto-occipital sulcus
what separates the frontal and parietal lobes?
the lateral sulcus
what is the pre central gyrus?
gyrus infront of the central lobe
what is the gyrus behind the central sulcus called?
post central gyrus
what does the precentral gyrus form?
primary motor cortex
what form the primary sensory cortex?
post central gyrus
what are the connections between the primary sensory and motor cortex?
fibers
why does a lesion to one of the primary cortex mean there are problems with sensory and motor systems?
connections between the two
what is the homonculi?
axons are arranged in a somatotropic arrangement
how are the head and face presented on the homunculi?
most laterally
how are the lower limbs represented on the homunculi?
medially
what are the exceptions to the homunculi arrangement?
somatosensory cortex, posterior columns
what is the journey of the corticospinal pathway?
arise in the primary motor cortex and run down via the internal capsule, through the pyramid and into the spinal cord
where is the pyramidal decussation?
at the end of the medulla
what are the fibers that decussate in the pyramids celled?
lateral corticospinal tract
where are the signs and symptoms of CNS problems?
usually conterolateraly
where are the signs and symptoms of PNS problems?
usually ipsilateral
how is the motor neuron for the upper face presented?
bilaterally
what do corticol and internal capsule lesions give rise to?
motor and sensory problems
what does a lesion in the pyramidal region cause?
purely motor problems
why does a lesion to the thalamus cause alot of problems?
alot of connections, alot of synapsing occurs here
how do lesions of the thalamus present?
controlateraly
how does the posterior colums rise?
ipsilaterally
what presents in a pons lesion?
discosiated sensory loss
what is the structure of the cerebellum?
two hemispheres and central vermis
what does the vestibular system of the thalamus control?
equilibrium and muscle tone
what is the hind brain also called?
rhombencephalon
what is the vestibular system also called?
floculanodular system
what does the palecerebellum control?
propulsive, stereotypes movement
what is the system of the palecerebellum?
spinocerebellum
what does the neurocerebellum control?
coordination of skilled voluntary movements
what is the formation of grey and white matter in the cerebellum?
grey is on the outside and white is on the inside
what does the right cerebellum control?
right side of the body
what does the vermis control?
the whole body
what are the two principle motor systems of the descending pathway?
pyramidal and extrapyramidal
what do the basal ganglia coordinate with?
upper motor neurons
what is the pyramidal system?
the direct activation pathway - voluntary movements
what is the extrapyramidal pathway?
the indirect pathway - control of movement
what is the indirect pathway for?
maintaining posture and balance, preplanned movement repertoire, compensatory movements, voluntary excitation on top of involuntary excitation
what does the indirect pathway facilitate?
selective activation or suppression of movements, initiation of movement, setting rate and force of movement, coordinating movement
what impulses does the indirect pathway control?
corticol neural impulses
what plans movement?
pre frontal cortex
what does the basal ganglia do to begin movement?
receives information which sends impulses to the cortex to initiate movement
