Spinal Cord Flashcards
(16 cards)
Spinal cord termination
Conus Medullaris (cone shaped structure) ~L1/L2 vertebral level
Begining of spinal cord
Foramen magnum
Cervical enlargement
nerves serving the upper limbs (C4-T1)
Lumbar enlargement
nerves serving the lower limbs (L2-S3)
Cauda Equina
Horse’s tail (after conus Medullaris) site of lumbar puncture and epidural-to avoid the spinal cord
Filum terminale
Arachnoid and Pia Mater extending from conus and connects to coccyx (acts as tether to anchor spinal cord in place)
3 regions of gray matter in spinal cord
Anterior (ventral) horn; Lateral horn; Posterior (dorsal) horn
Anterior (ventral) horn
Motor-efferent-outgoing
Lateral horn
Sympathetic; only found in T1-L2 levels as that’s where the sympathetic nervous system originates
Posterior (dorsal) horn
Sensory-afferent-incoming
White matter of spinal cord
myelinated axons arranged into tracts (carry info throughout CNS)
Ascending tracts
Carries sensory information (Spino-____)
Descending tracts
Carries motor information (_____-spinal)
Motor Pathway (Pyramidal [corticospinal] tracts)
initiates voluntary movement; 2 neurons in pathway
Upper motor neuron > cell body in motor cortex; synapse in ventral horn
Lower motor neuron > cell body in ventral horn; synapse with skeletal muscle (at NMJ)
Motor Pathway (extra Pyramidal tracts)
Coordinates voluntary movement
Sensory Pathway (all)
3 neurons
1 (primary) neuron: originates somewhere in body; cell body in dorsal root ganglia; synapse in dorsal horn
2 (secondary) neuron: originates in dorsal horn; synapses in thalamus
3 (tertiary) neuron: originates in thalamus; synapses in primary sensory cortex (post central gyrus)
