Final Exam (based off review) Flashcards
Lecture & Lab
What are the 4 Somtosensory Conscious Pathways?
- Dorsal Column Upper Tract (Cuneatus)
- Dorsal Column Lower Tract (Gracilis)
- Anterior Spinothalamic Tract
- Lateral Spinothalamic Tract
Somatosensory Conscious Pathways Order:
1st order neuron (DRG) >DR> 2nd order (medulla) neuron > 3rd order neuron (VP thalamus) > internal capsule > corona radiata > postcentral gyrus
Dorsal Column Pathway (Lower tract, fasciculus gracilis):
DRG (1st cell body)
DR
Fasciculus gracilis (first axon)
Nucleus gracilis (2nd cell body)
Medial lemniscus (second axon “decussate”)
VP thalamus (3rd cell body)
Internal capsule (third axon)
Corona radiate
Postcentral gyrus
Dorsal Column Pathway (Upper tract, fasciculus cuneatus):
DRG (1st cell body)
DR
Fasciculus cuneatus (first axon)
Nucleus cuneatus (2nd cell body)
Medial lemniscus (second axon “decussate”)
VP thalamus (3rd cell body)
Internal capsule (third axon)
Corona radiata
Postcentral gyrus
Anterior Spinothalamic Tract Pathway:
DRG > DR > DH > AST > VP Thalamus > Internal Capsule > Corona Radiata > Postcentral gyrus
Lateral Spinothalamic Tract Pathway:
DRG > DR > DH > LST > VP Thalamus > Internal Capsule > Corona Radiata > Postcentral gyrus
Where do the dorsal column tracts 2nd order neuron decussate?
medulla (medial lemniscus)
What type of sensations are the dorsal column tracts responsible for?
fine touch and proprioception
What type of sensations is the anterior spinothalamic tract responsible for?
crude touch and pressure
What type of sensations is the lateral spinothalamic tract responsible for?
pain and temperature
What are the 2 Somatosensory Unconscious Pathways?
- Anterior Spinocerebellar Tract
- Posterior Spinocerebellar Tract
Anterior Spinocerebellar Tract:
DRG > DR > DH > lateral column (deccusate) > AST > inferior peduncles > cerebellar cortex
Posterior Spinocerebellar Tract:
DRG > DR > DH > lateral column (deccusate) > PST > superior cerebral peduncles > cerebellar cortex
What type of sensations are the Posterior & Anterior Spinocerebellar Tract Pathways responsible for?
Subconscious proprioception
What are the 3 Somatomotor Conscious Pathways? (pyramidal tracts)
corticospinal pathway
anterior corticospinal tract
lateral corticospinal tract
corticobulbar tracts
What are the somatomotor pathways responsible for?
subconscious movement of muscle
What type of sensations is the anterior corticospinal tract responsible for?
gross motor
What type of sensations is the lateral corticospinal tract responsible for?
fine motor
Corticospinal pathway:
What type of sensations is the corticospinal tract responsible for?
subconscious movements of the body
Lateral corticospinal pathway: (Contralateral) 75%-90% Fine Motor
Precentral gyrus (UMN) >
Corona radiata >
Internal capsule >
Cerebral peduncles >
Pyramids >
LCT >
Lateral Column >
Ventral horn (LMN)
Anterior corticospinal pathway: (Contralateral) 10%-25% Gross Motor
Precentral gyrus (UMN) >
Corona radiata >
Internal capsule >
Cerebral peduncles >
Pyramids >
ACT >
Lateral Column >
Ventral horn (LMN) (decussate)
Corticobulbar tract pathway:
Precentral gyrus (UMN) >
Corona radiata >
Internal capsule >
Cerebral peduncles >
Motor nuclei of cranial nerves 3-12 (LMN)
What type of sensations is the corticobulbar tract responsible for?
subconscious movements of the head