spinal cord anatomy: descending tracts and spinal cord blood supply Flashcards
What part of the internal capsule of the ganglia contains the sensory fibers along with the corticospinal/pyramidal system (leg, trunk, arm, face)?
posterior limb
Once the corticospinal tract reaches the medulla, 85% of the fibers branch off and become the ____.
Lateral corticospinal tract
Once the corticospinal tract reaches the medulla, 15% of the fibers branch off and become the ____.
anterior corticospinal tract
What does the lateral corticospinal tract supply?
Everything except the axial muscles.
What does the anterior corticospinal tract supply?
axial muscles
Where does the rubrospinal tract originate?
red nucleus of the midbrain
The rubrospinal tract (does/does not) receive input from the cortex.
It does
What pathway is only found in the cervical segments?
rubrospinal tract
What does the rubrospinal tract innervate?
Flexors of the UE
Where does the medial vestibulospinal tract originate?
medial vestibular nucleus
What does the medial vestibulospinal tract innervate?
Head and neck muscles
Does the medial vestibulospinal tract become bilateral or does it stay unilateral?
It becomes bilateral for the cervical spine
Where does the lateral vestibulospinal tract originate?
lateral vestibular nucleus
Does the lateral vestibulospinal tract become bilateral or does it stay unilateral?
It stays unilateral
What pathways are believed to have involvement with muscle spasticity?
Reticulospinal tract
What do the reticulospinal tracts do as a whole?
Provide postural control/tone
Where does the medial reticulospinal tract originate?
Reticular formation in the PONS
Does the medial reticulospinal tract become bilateral or does it stay unilateral?
It stays unilateral
What does the medial reticulospinal tract do?
excites the extensors and axial muscles
Where does the lateral reticulospinal tract originate?
reticular formation of the MEDULLA
Does the lateral reticulospinal tract become bilateral or does it stay unilateral?
It is bilateral at ALL levels
What does the lateral reticulospinal tract do?
It excites the flexor muscles
What does the reticular formation receive information from?
cortex and basal ganglia
(true/false) The anterior spinal artery only goes down to the thoracic level.
False (it travels down the whole spinal cord)
What is considered as the “watershed of the spinal cord?”
anterior spinal artery
What arteries supply blood to the anterior spinal artery at every level?
anterior radicular arteries
where do the anterior radicular arteries branch off of?
the aorta
What level(s) of the spinal cord have the least amount of blood going to the anterior spinal artery?
T4-T8
The anterior spinal artery provides blood to ___ of the spinal cord.
2/3
The posterior spinal artery provides blood to __ of the spinal cord.
1/3 (dorsal columns)
Where is the venous plexus found in the vertebral column?
Epidural space
What is unique about the venous plexus in the vertebral column?
They do not have valves
