Neural Pathways Flashcards
(26 cards)
Neural Pathways(3)
1) Consist of tracts and Nuclei 2) Can be ascending(sensory) or descending(motor) 3) most decussate(cross)
Sensory (ascending pathways) 3 types and neurons#
Uses 2-3 Neurons 1)Primary 1st order 2) Secondary 2nd order 3) Tertiary 3rd Order
Primary Sensory pathway
Dendrite: sensory receptor Soma: dorsal root ganglion or sensory ganglion of cranial nerve
Secondary Sensory Pathway
Interneuron: Axon in Thalamus(conscious) or cerebellum(unconscious)
Tertiary Sensory Pathway
Interneuron; Soma in Thalamus
Posterior Funiculus-medial lemniscal FUNCTION
Conducts info related to LIMB Position discrimitive touch; precise pressure vibration (3 NEURONS)
Posterior Funiculus-medial lemniscal Pathways(1st 2nd 3rd)
1st) Enter SC and ascends in fascicules cuneatus or fasciculus gracilis 2nd) Synapse w 2 in medulla (decussate) axons project to thalamus 3rd) 2nd synapse with 3rd can carries impulse to cerebral cortex
Anterolateral pathway Function
Conducts info related to crude touch & pressure; pain; & temperature
Anterolateral pathway 2Parts
Anterior spinothalamic tract and Lateral spinothalamic tract
Anterolateral pathway 1st 2nd 3rd
1st)1st synapses w/ 2nd in posterior horn 2nd)Decussate before ascending (white commissure) 3rd synapses w/ 3rd at thalamus 3rd) 3rd goes to cerebral cortex
Spinocerebellar Pathway 2 parts and difference
1) Anterior spinocerebellar tract (Trunk; lower limbs) 2) Posterior spinocerebellar tract (also includes UPPER LIMB)
Spinocerebellar Pathway Function
Conducts info that coordinates body movement and maintains posture
Spinocerebellar Pathway Synapses (1-3)(anterior vs posterior)
1st) 1st synapses w/ 2nd at posterior horns 2nd) 2nd goes to cerebellum (Anterior: decussates in SC Posterior: does not decussate)
Motor (descending) pathways(3)
1) Have upper and lower motor neurons 2)Direct (pyramidal): conscious control of sk muscle (Originate in cerebral cortex ) 3)Indirect (extrapyramidal): unconscious control of sk muscle (Originate in brainstem)
Direct Motor pathway
(pyramidal) conscious control of sk muscle (Originate in cerebral cortex)
Indirect Motor Pathway
(extrapyramidal): unconscious control of sk muscle Originate in brainstem
Corticobulbar tract Char
Forms Primary Motor Cortex UMN synapses w/ LWN in brainstem (LMN forms several cranial nerves controlling) EYES/facial throat muscles back and neck
Corticobulbar track What type
DIRECT Motor
Corticospinal Tract Type
Direct motor
What does the Corticospinal tract From
Bulges in the Medulla(PYRAMIDS)
Lateral Corticospinal tract
UMN decussate in medulla; UMN in lateral funiculus synapse to LMN in ANTERIOR HORN LMN TO SK MUSLCE PERFORMING SKILLED MOVEMENT
Anterior Corticospinal Tract
UMN in anterior funiculus; UMN decussate in SC Synapse to LMN in anterior Horn; LMN to AXIAL SK MUSCLE
Rubrospinal Tract Type and what is regulates
Indirect(unconscious) Motor; Regulates precise movements and tone of limb flexor muscles
Rubrospinal Tract Originates?
Red nucleus of Mesencephalon(brain stem)
