Spinal Tracts: Ascending And Descending Tracts Flashcards
What are the ascending tracts of the spinal cord?
Responsible for sensory information. Divided into the conscious sensory tracts and the unconscious sensory tracts.
What is the role of the anterior spinothalamic tract?
Crude touch and pressure.
What is the role of the lateral spinothalamic tract?
Pain and temperature.
What is the role of the dorsal column tract?
Fine touch, propioception and vibration.
What is the significance of the fasiculus gracilis?
Dorsal column pathway below T6 for the lower limbs.
What is the significance of the fasiculus cuneatus?
Dorsal column pathway above T6 for the upper limbs.
What are the unconscious sensory tracts?
Spino-cerebellar
Spino-tectal
Spino-olivary
Spino-reticular
What is the role of the spino-olivary tract?
Transmit propioceptive information to the inferior olivary nucleus, for balance.
What is the role of the spino-cerebellar tract?
Unconscious propioceptive information from the muscle spindles and Golgi Tendon to the cerebellum.
What is the role of the spino-reticular tract ?
Provides information to reticular formation for consciousness, awareness and emotional response to pain.
What is the role of the spino-tectal tract?
Sensory information to transmit to the superior colliculi for orientation of our eyes and head.
What are the descending tracts?
Motor actions which are divided into pyramidal and extra-pyramidal tracts.
What are the pyramidal tracts?
Tracts which arises from the cortex and travels through the pyramids of the medulla. This includes the corticospinal and corticobulbar tract.
What are the extrapyramidal tracts?
Arise from the brain stem and are responsible for unconscious motor actions, not passing through the pyramids of the medulla:
Tectospinal
Vestibulospinal
Reticulospinal
Rubrospinal
What is the role of the anterior corticospinal tract?
Voluntary control of the ipsilateral and contralateral axial and trunk muscles. It is ipsilateral at the pyramids.
What is the role of the lateral corticospinal tracts?
Voluntary control of the contralateral distal limbs. Makes up a majority of fibres which decassate at the pyramids.
What is the role of the rubrospinal tract?
Extrapyramidal tract which is responsible for fine control and flexor muscles.
What is the role of the tectospinal tract?
Originates from the superior colliculi to transmit to the head and eyes for orientation in response to auditory and visual stimuli.
What is the role of the medial vestibulospinal tract?
Act on the head and neck ipsilateral extensor muscles for posture and balance, exiting at the cervical segment.
What is the role of the lateral vestibulospinal tract?
Acts on the appendicular extensor muscles of the limbs, exiting at the thoracic segment.
What is the role of the medial reticulospinal tract?
Arises from the pons to increase muscle tone and facilitate voluntary movement.
What is the role of the lateral reticulospinal tract?
Receives information from the corticoreticular fibres. It arises from the medulla and inhibiting voluntary movement and reduce muscle tone, involved in automatic breathing.
Lesion to the pyramidal tract?
Positive Babinski sign with dorsiflexion, hyperreflexia, hypertonia and weakness.
Lesion to the extrapyramidal tract?
Parkinsonism with rigidity, tremor and postural defects. Dystopia may occur, which is involuntary muscle spasms.
How does an UMN lesion present?
Hypertonic
Hyperreflexia
Clonus
Weakness
Positive babinski sign
How does a LMN lesion present?
Fasiculation
Muscle atrophy
Hypotonia
Hyporeflexia
Flaccid paralysis
