Ascending Tracts Flashcards
Sensory modalities we’re concerned with?
Proprioception and Nociception (pain)
Where in the spinal cord?
Dorsal and lateral funiculi
Most superficial tracts in lateral funiculi
Pelvic limb tracts more superficial
Pathway of conscious proprioception
Afferent neuron –> interneuron in medulla –> medial lemniscus –> thalamus –> relay neuron –> parietal lobe of cerebrum
Dorsal and ventral spinocerebellar tracts
Unconscious proprioceptive
Caudal peduncle to cerebellum
No cross over
Pelvic limbs
Cuneocerebellar tract
Unconscious proprioceptive Caudal peduncle to cerebellum No cross over Thoracic limbs Ascend in fasciculus cuneatus
Rostral spinocerebellar and Cervicospinocerebellar tracts
Unconscious proprioceptive
Caudal peduncle to cerebellum
No cross over
Thoracic limbs and neck
Fasciculus cuneatus
Conscious proprioceptive
Cerebral cortex of parietal lobe
100% crossover in medulla
Thoracic limbs
Fasciculus gracilis
Conscious proprioceptive
Cerebral cortex of parietal lobe
100% crossover in medulla
Pelvic limbs
Spinomedullary and Spinocervicothalamic tracts
Conscious proprioceptive
Cerebral cortex of parietal lobe
100% crossover in medulla
Both limbs and trunk
Lateral spinothalamic tract
Nociception (pain)
Spinal cord to parietal lobe
Domestic animals - travels back and forth through BOTH lateral funiculi
Damage to proprioception tracts?
loss of coordination = ataxia and abnormal gait
WITHOUT paresis/paralysis or spasticity
Damage to pain tracts?
partial/complete loss of conscious pain perception
Pain from Head
100% crossover
CN V –> trigeminal ganglion –> pons (spinal tract of CN V –> nucleus of spinal tract of CN V) –> medial lemniscus –> thalamus –> internal capsule –> parietal lobe of opposite side
Ascending Reticular Activating System (ARAS)
responsible for mentation = level of awareness
keeps cortex awake and aroused
sensory projection neurons –> RF –> thalamus –> relay neurons –> all cerebral cortex areas
Reticular formation (RF)
collection of cell bodies in middle of brain stem