Nervous System Flashcards
Classifications of the spinal tracts
- Spinothalamic (Antero-lateral)
- Dorsal Column Medial Lemniscus 3. Spinocerebellar
- Trigemino-thalamic
Modalities for spinothalamic tract
Anterior: crude touch, pressure
Lateral: pain and temperature
Process for spinothalamic tract
1º neuron at drg
2º neuron at DH of grey matter @ spinal cord, decussates and crosses midline to
3º neuron at thalamus
sensory cortex (post central gyrus) in cerebral cortex (where sensory information is CONSCIOUSLY perceived)
Modalities for dorsal column medial lemniscus
- Fine, discriminative touch
- Vibration and pressure
- Conscious proprioception
Process for DCML
1º neuron at DRG, receives stimulus from Meissner’s corpuscles, Pacinian corpuscles
2º neuron at MEDULLA OBLONGATA decussates & crosses midline
3º neuron at THALAMUS where sensory information is processed and relayed to
sensory cortex
Functions of spinocerebellar system
- Control muscle tone
- Coordination
- Regulate movements
Process of spinocerebellar system
1º neuron at DRG
2º neuron at DH @ spinal cord
(1) Dorsal spinocerebellar tract (dominant), DO NOT CROSS –> inferior cerebellar peduncle (cerebellum)
(2) Ventral spinocerebellar tract, DECUSSATES –> superior cerebellar peduncle (cerebellum)
What are the 4 cutaneous mechanoreceptors
- Meissner’s corpuscles
- Merkel’s disc
- Ruffini nerve ending
- Pacinian corpuscle
Function of Meissner’s Corpuscle
Changes in texture, slow vibrations
Function of Merkel’s disc
Sustained touch and pressure
Function of Ruffini’s nerve endings
Sustained pressure
Classification of the Somatic Motor Pathways
PYRIMIDIDAL SYSTEM
1. Corticospinal tract
2. Corticobulbar tract (Nuclear)
EXTRAPYRIMIDAL SYSTEM
1. Rubrospinal tract
2. Tectospinal tract
3. Vestibulospinal tract
4. Reticulospinal tract
Function and process of rubrospinal tract
- Neuronal cell bodies of UMNs @ RED NUCLEUS of midbrain
- VH of spinal cord (synapse)
- LMNs → FLEXOR MUSCLES
Function and process of TECTOspinal tract
- Neuronal cell bodies of UMNs @ superior colliculus/ TECTUM of midbrain
- VH of spinal cord
- LMNs → REFLEX TO VISUAL STIMULI