Ascending Tracts

Question 0

Sensory modalities we’re concerned with?

Answer 0

Proprioception and Nociception (pain)

Question 1

Where in the spinal cord?

Answer 1

Dorsal and lateral funiculi
Most superficial tracts in lateral funiculi
Pelvic limb tracts more superficial

Question 2

Pathway of conscious proprioception

Answer 2

Afferent neuron –> interneuron in medulla –> medial lemniscus –> thalamus –> relay neuron –> parietal lobe of cerebrum

Question 3

Dorsal and ventral spinocerebellar tracts

Answer 3

Unconscious proprioceptive
Caudal peduncle to cerebellum
No cross over
Pelvic limbs

Question 4

Cuneocerebellar tract

Answer 4

Unconscious proprioceptive
Caudal peduncle to cerebellum
No cross over
Thoracic limbs
Ascend in fasciculus cuneatus

Question 5

Rostral spinocerebellar and Cervicospinocerebellar tracts

Answer 5

Unconscious proprioceptive
Caudal peduncle to cerebellum
No cross over
Thoracic limbs and neck

Question 6

Fasciculus cuneatus

Answer 6

Conscious proprioceptive
Cerebral cortex of parietal lobe
100% crossover in medulla
Thoracic limbs

Question 7

Fasciculus gracilis

Answer 7

Conscious proprioceptive
Cerebral cortex of parietal lobe
100% crossover in medulla
Pelvic limbs

Question 8

Spinomedullary and Spinocervicothalamic tracts

Answer 8

Conscious proprioceptive
Cerebral cortex of parietal lobe
100% crossover in medulla
Both limbs and trunk

Question 9

Lateral spinothalamic tract

Answer 9

Nociception (pain)
Spinal cord to parietal lobe
Domestic animals - travels back and forth through BOTH lateral funiculi

Question 10

Damage to proprioception tracts?

Answer 10

loss of coordination = ataxia and abnormal gait

WITHOUT paresis/paralysis or spasticity

Question 11

Damage to pain tracts?

Answer 11

partial/complete loss of conscious pain perception

Question 12

Pain from Head

Answer 12

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

Question 13

Ascending Reticular Activating System (ARAS)

Answer 13

responsible for mentation = level of awareness
keeps cortex awake and aroused
sensory projection neurons –> RF –> thalamus –> relay neurons –> all cerebral cortex areas

Question 14

Reticular formation (RF)

Answer 14

collection of cell bodies in middle of brain stem

Question 15

Terminology associated with changes in mentation:
BAR - 
depressed/obtunded -
semicomatose/stuporous - 
comatose - 
brain dead -

Answer 15

BAR - normal
depressed/obtunded - dull, sleepy
semicomatose/stuporous - responds to pain stimulus
comatose - totally unresponsive, PLR and oculocephalic reflex intact
brain dead - totally unresponsive, PLR and oculocephalic reflex absent