Neurophys Flashcards
(55 cards)
Rubrospinal tract
originates in red nucleus and decussates and projects to interneurons in lateral spinal cord. stimulation produces stimulation of flexors and inhibits extensors-primarily hands
Where are Pacinian corpuscles found and what do they detect?
found in subcutaneous skin surrounding unmyelinated nerve endings, sense vibration/tapping
What is the hypothalamus the autonomic center for (2)?
Temperature regulation center, thirst and food intake regulatory centers
Lateral corticospinal tract
from inferior medulla, decussates and descends into SC, terminates in ventral horn of all spinal levels
What is the overall function of the cerebellum? What 3 areas are in the cerebellum?
central control of movement, vestibulocerebellum, pontocerebellum, spinocerebellum
Where does the optic N and optic tract end? Where does it go from there?
end in lateral geniculate body of the thalamus, fibers from there form the geniculocalacrine tract and pass to occipital lobe of cortex
Medullary reticulospinal tract
originates in medullary reticular formation and projects to spinal cord interneurons in intermediate gray area. Stimulation has inhibitory effect on flexors and extensors but mainly extensors
Where are Ruffini corpuscles found and what do they detect?
they are encapsulated
detect pressure
Medial reticulospinal tract
arises from pons, facilitates voluntary movement and increases muscle tone
tectospinal tract
originates in superior colliculus and projects to cervical spinal cord. Involved in control of neck muscles
Lesions above the pontine reticular formation but below the midbrain
cause decerebrate rigidity because of removal of cintral inhibition from the pontine reticular formation
lateral spinothalamic tract function
pain and temp
Lateral vestibulospinal tract
originates in Deiters nucleus and projects to ipsilateral motoneurons and interneurons. Stimulation causes a powerful stimulation of extensors and inhibition of flexors
Corticospinal tract pathway up to division
Orig in cerebral cortex, neurons converge and descend through internal capsule then through crus cerebri of midbrain, then pons then into medulla-in the most infereior medulla divide into 2 tracts
What are the exceptions of the corticobulubar tract fibers that do not innervate motor neurons bilaterally?
UMN for CNVII have contralateral innervation
UMN for CNXII have contralateral innervation
What provides inputs to corticospinal tracts
primary motor cortex, premotor cortex and supplementary motor N
What is the course of the dorsal column system?
primary afferent neurons have cell bodies in dorsal root. Axons ascend ipsilaterally to nucleus gracillis and nucleus cuneatus of medulla. From medulla, 2nd order neurons cross midline to contralteral thalamus, 3rd order ascend to somatosensory corte
Corticobulbar tract pathway
arise from primary motor cortex, fibers converge and pass through internal capsule of brainstem and terminate on motor nuclei of cranieal nerves. Here they synapse with LMN and innervate M of head and neck
Rubrospinal tracts
originates from red nucleus in midbrain, decussates and desends into SC, control fine control of hand movements
What is the midbrain the autonomic center for?
Micturition center
lateral reticulospinal tract
arises in medulla, inhibits voluntary movement and decreases muscle tone
posterior spinocerebellar tracts
carry proprioception info from lower limbs to ipsilateral cerebellum
Effect of lesion above the lateral vestibular nucleus
cause decerebrate rigidity because of the removal of inhibition from higher centers
What does DCML transmit?
fine touch (tactile), vibration and proprioception
