brainstem nuclei and tracts Flashcards
are descending tracts motor or sensory
motor
are ascending tracts motor or sensory
sensory
brainstem
- a pathway for tracts running between higher and lower neural centers
- located between cerebrum and spinal cord
- produces automatic behaviors necessary for survival
brainstem consists of …
deep gray matter surrounded by white matter fiber tracts
which nerves are in the pontomedullary junction
- trigeminal nerve
- abducens nerve
- facial nerve
- vestibulocochlear nerve
three levels of motor and sensory pathways
- cortex/basal ganglia/ cerebellum/thalamus
- brainstem
- spinal cord
corticobulbar tract
from the cortex to the brainstem
corticospinal tracts
from the cortex to the spinal cord
primary motor pathways
- corticobulbar
- corticospinal tracts
lateral corticospinal tract function
conveys commands to the body (playing the piano, tap dancing)
anterior corticospinal tract function
controls trunk muscles (core exercises)
what do the 3 levels of sensory pathways recieve input from
sensory receptors
direct connection between the cerebellum, basal ganglia, and final common pathway
none
feedback loops involving two independent subcortical systems …
modulate activity at the brainstem and cortical levels
what does the cerebral aqueduct separate
anterior and posterior midbrain
substantial nigra function
- dopamine production to inhibit the basal nuclei excitatory neurons
- voluntary movement
midbrain nuclei
- red nuclei
- nuclei of cranial nerves 3 and 4
- substantial nigra
red nuclei
- contains numerous blood vessels
- receives info from the cerebrum and cerebellum
- issues subconscious motor commands concerned with muscle tone and posture
midbrain tracts
- motor tracts
- sensory axons
- cerebral peduncles
midbrain motor tract
- include pyramidal system
- pass downward on the midbrain’s ventral surface
midbrain sensory axons
- including spinothalamic tract
- ascend along the dorsal midbrain
midbrain cerebral peduncles
- efferent projections include corticobulbar and corticospinal axons
corpora quadrigemina parts
- two superior colliculi
- two inferior colliculi
superior colliculi
- visual system
- relaying input from the optic tract to the lateral geniculate bodies of the thalamus
inferior colliculi
- auditory pathway
- send information to the medial geniculate bodies of the thalamas
reticular activating system
present throughout the brainstem and is involved in the sleep-wake cycle
pons nuclei
- sensory and motor nuclei for trigeminal, abducens, facial, and vestibulocochlear nerves
- apneustic and pneumotaxic centers work with the medulla (maintains respiratory rythym)
- raphe nuclei
- reticular activing system
pons tracts
- superior, middle, and inferior cerebellar peduncles
- motor and sensory tracts traverse the anterior surface of the pons
- sensory fibers are posterior to the motor fibers
medulla nuclei
- autonomic nuclei
- sensory and motor nuclei of glossopharyngeal, vagus, accessory, and hypoglossal nerves
- relay nuclei
medulla autonomic nuclei
- cardiovascular (alter rate and force of cardiac contractions, alter the tone of vascular smooth muscle)
- respiratory rhythmicity centers (receive input from the pons)
- additional centers (emesis, deglutition, coughing, hiccuping, and sneezing)
medulla relay nuclei
- nucleus gracilis
- nucleus cuneatus
- olivary nuclei
nucleus gracilis and nucleus cuneatus
pass somatic sensory information to the thalamas
olivary nuclei
relay info from the spinal cord, cerebral cortex, and the brainstem to the cerebellar cortex
medulla tracts
corticospinal tracts
what forms the medullary pyramids
large motor corticospinal tracts
