Spinal Cord Flashcards
What path does discriminative sensation take in the spinal cord?
Pseudounipolar neuron, ending in lamina’s 3 and 4/ Nucleus Proprius or in the gracile and cuneate faciculi.
They arranged in the fasculi like that of the homunculus. The lower limb in the gracile (medial) fasciculus and the upper limb in the cuneate fasciculus, with the hand neurons being located next to the dorsal intermediate sulcus.
Goes up to the brain to the primary sensory cortex
What path does non discriminative/ pain and temperature fibres take?
Pseudounipolar neuron the synapses on lamina’s 1 and 2.
They then decussate and enter the spinothalamic tract in the ventral funiculi. Up the spinal cord to the primary somatosensory cortex.
What path does the motor pathway take through the spinal cord?
UMN’s travel down the lateral funiculus and synapse with the LMN’s in the laminas 8 and 9. Then out the ventral root.
What is the myotactic reflex at the level of the spinal cord?
In order to coordinate the flexors and extensors to move smoothly. The discriminative fibres synapse in lamina 8 and 9 to the LMN’s to coordinate them efficiently.
Relatively fast, heavily myelinated
What is the withdrawal reflex at the level of the spinal cord?
Non discriminative sensation will travel to lamina’s 1 and 2. A fibre will then synapse in lamina 8/9 which cooridnates the LMN’s to work.
3 neurone reflex so polysynaptic reflex thus slower
Lamina 1 vs lamina 2
Both pain and temp fibres but lamina 2 has opiod receptors so anaesthetic will affect this.
What is the nucleus proprius?
Combination of laminas 3 and 4
What do laminas 5 and 6 deal with?
Noxious visceral stimuli
What is lamina 7 and what is the role of the dorsal nucleus of Clark?
Lamina 7 is mainly ANS however the dorsal nucleus of Clark contains the spinocerebellar tract plus involved in unconscious proprioreception.
How are lamina’s 8 and 9 arranged?
Broadly, the flexors are dorsal and the extensors ventral.
