Spinal Cord Organization January 9 2008 Spinal Cord
- Slides: 36
Spinal Cord Organization January 9, 2008
Spinal Cord 31 segments terminates at L 1 -L 2 special components - conus medularis - cauda equina no input from the face
Spinal Cord, Roots & Nerves Dorsal root Ventral root Spinal nerve
Dorsal Root Ganglion Cell bodies of 1 st order sensory neurons Afferent
Spinal Cord Cross Section Dorsal root sensory afferent Ventral root motor efferent
Cross Section of Spinal Cord White matter peripheral Central canal Gray matter central
Volume of Gray & White Matter Gray matter enlarges at cervical and lumbar regions. White matter increases at higher levels of the cord.
Central Gray Matter Motor neurons 2 nd order sensory neurons Interneurons Motor neuron = lower motor neuron = anterior horn cell = second order motor neuron Glial cells
Organization of Gray Matter Pain Temperature
Organization of Gray Matter Position sense Vibration Pressure Touch
Organization of Gray Matter Position sense Neck & base of Posterior Horn from legs Between T 1 and L 2 enlarged Dorsal nucleus of Clarke 2 nd order sensory neuron going to cerebellum
Organization of Gray Matter Intermediolateral Horn Interomediolateral horn Between T 1 and L 2 enlarged Sympathetic neurons (preganglionic)
Sympathetic Innervation
Organization of Gray Matter Intermediolateral Horn . At S 2, S 3, and S 4 Parasympathetic neurons (preganglionic)
Parasympathetic Innervation
Organization of Gray Matter Modulates motor activity via gamma motor neurons Adjusts briskness of deep tendon reflexes
Organization of Gray Matter Nuclei of alpha and gamma motor neurons Innervates muscle spindles and muscles
Lower Motor Neurons Alpha motor neurons originate from Rexed lamina IX ventral – dorsal organization ventral extensor muscles dorsal flexor muscles medial – lateral organization medial proximal muscles lateral distal muscles
Somatotopic Organization
Coordinating Role of Interneurons
Breathing Nuclei of alpha and gamma motor neurons LMNs from spinal levels C 3, C 4 & C 5 innervate the phrenic nerve Controls diaphragm
Control Functions Nuclei of alpha and gamma motor neurons At levels S 1 - S 4 LMNs form Onuf’s nucleus Innervates anal and urethral spincters; needed for sexual function
Sacral cord
Configuration of Gray Matter Abundant white matter high in the spinal cord Enlargement of gray matter at the cervical level Innervates arm muscles
Configuration of Gray Matter Enlargement in thoracic region for sympathetic neurons Enlargement in lumbar region for motor neurons to the legs Minimal white matter at the lower cord
Descending Motor Pathway Upper motor neuron 1 st order neuron synapses on LMN Crossed pathway Lateral corticospinal Uncrossed pathway Anterior corticospinal
Somatotopic Organization
Spinal Cord Tracts Unconscious position sense movement feedback
Ascending & Descending Tracts • ↑ Sensory – Gracile tract • Leg position & vibration – Cuneate tract • Arm position & vibration – Dorsal spinocerebellar tract • Strength & muscle speed – Ventral spinocerebellar tract • Modulation; interneurons – Lateral spinothalamic tract • Pain & temperature – Anterior spinothalamic tract • Light touch – Spinocervical thalamic tract • Kinesthetic movement & discriminative touch • ↓ Motor – Corticospinal tract • Speed & agility – Reticulospinal tract • Differential facilitation of motor neurons – Rubrospinal tract • Fix movement errors – Lateral vestibulospinal tract • Extensor & posture – Medial vestibulospinal tract • Flexor & head position – Tectospinal tract • Head turning
Ascending Tracts Sensory Position Vibration Sensory Pain Temperature
Spinal Cord Injury Position Pain Brown – Sequard Syndrome
Transverse vs Hemi Cord Syndrome
Anterior vs Posterior Cord Syndromes
Blood Supply to Spinal Cord
Traumatic Spinal Cord Injury DUI: $100 addt’l fine South Carolina Spinal Cord Injury Research Board
Monday Brainstem
- Art-labeling activity figure 13.6a (1 of 2)
- Figure 13-2 spinal nerves
- Spinal cord anatomy
- Spinal cord structure
- Spinal cord organization
- 2008 2008
- Autonomic nervous system table
- Dorsal nerve cord vs notochord
- Interneuron
- Sulcus limitans
- Diet for spinal cord injury patient
- Spinal cord structures
- Somatic nervous system
- Spinal cord
- Spinal cord 31 pairs
- Corticospinal tract.
- Posterior median furrow
- Christopher reeve ventilator
- Blastocoal
- Spinal cord
- Spinal cord histology diagram
- Components of the reflex arc
- Spinal cord anatomy
- Functional unit of nervous system
- Articularis cubiti
- Poikilothermism and spinal cord injury
- Tethered cord icd 10
- Hyporeflexia and hyperreflexia
- Spinal cord cross section
- Spinal angiogram
- Spinal cord muscles
- Boston scientific spinal cord stimulator
- Connective tissue layer
- Intervertebral disc prolapse
- Spinal cord diagram
- Spinal cord spasticity
- Spinal cord level