Lecture 5- Motor Ad Sensory Pathways Flashcards
Most ascending sensory pathways (except olfactory) are relayed via the ……… and project to ……… …….?
Thalamus
cerebral cortex
Area ……: Broca’s area:
contains movement patterns for
making …….. ……… ……… ………?
44
Speech sounds and writing
Major descending motor tracts from ……. ……. generally bypass ……… on the way down to thespinal cord.
cerebral cortex
thalamus
Stimulation of motor cortex produces muscle contraction on
…………….. side of body.
contralateral
Basal ganglia concerned with controlled purposeful
movements. They integrate info from ……… …….., process it and project it back to ……. through the ………..
cerebral cortex
cortex
thalamus
Functional disturbances of basal ganglia will cause ……… ………?
movement disorders.e.g Parkinson’s
Motor pathways:
Corticospinal tract is the main pathway controlling ……. ……..?
Voluntary pathways
Motor pathways:
Axons originate from …….. ……. …….. cell bodies in the cerebral motor cortex (in posterior frontal lobe) and pass to the medulla where they form the ……….. ………
upper motor neuron
medullary pyramids.
Motor pathways:
Most fibres decussate at pyramids to form the ……… ……… …….?
lateral corticospinal tract.
Fibres that don’t decussate form the ……… …….. …….?
anterior (ventral) corticospinal tract.
Motor pathway:
Synapse with …… …… ……. in the ……… ……… horn of spinal cord grey matter.
lower motor neurons
anterior (ventral)
Lateral corticospinal => mediates …….. control of movement of …… and motor functions of CN IX, CN X and CN XII (9,10,11)
(decussates at pyramids).
voluntary
limbs
Ventral corticospinal =>………. tract that eventually crosses the spinal cord to synapse with ……. horn and control of ……. muscles.
uncrossed
anterior
axial
Rubrospinal => from …….. …….. to spinal cord. Role in control of …….. …….?
red nucleus
flexor tone
Vestibulospinal => from …… ……. to spinal cord. Role in control of ……… …….. and maintenance of ……… And ………
vestibular nuclei
extensor tone
posture and balance
Somatosensory “Body sense” • Pain • Temperature • Simple touch • Proprioception (perception of .......) • Kinesthesia (perception of .........) • Stereognosis (perception of ..... and ...... of objects by touch).
position
movement
Size and shape
Somatosensory afferents feed into ……… and also distribute to ……… ………. and cerebellum.
reflexes
cerebral cortex
Nociceptors (pain) = ……. …… receptors
50% skin
Proprioceptive info transmitted via ……. ……., ……… …… …… and joint receptors
muscle spindles
golgi tendon organ
Larger receptive fields for areas of skin that ……. need …… ………
don’t
fine resolution.
For ……. …….. sensation multiple small receptive fields, packed closely.
finer tactile
Two-point discrimination:
~ 2-3mm on …… ……
~35-40mm on ……
~40mm on ……
Fingertips
Arm
Back
Somatotopic organisation:
each body region represented in a particular ……. …….
cortical area.
Represented in proportion to their sensory innervation – not
actual ……. …….
body size
