Quesmed Neuro pathways Flashcards
Which level of the brain do corticospinal tract decassate?
At the level of the pyramids in the medulla.
What does the corticospinal tract synapse with?
Spinal cord interneuorns mainly
Alpha motor neurons
Where do first order neurons for the spinothalamic synapse?
They enter the spinal cord and travel up Lissaeur’s tract to synapse with second order neurons in Lamina II
What is the second -> third order for spinothalamic?
Second order travels as the spinal leminiscus to synapse onto 3rd order neurons in the thalamus.
Which tract forms the fasiculus cuneatus and fasiculus gracilis?
Dorsal column from first Oder neurons. These travel up and synapse with second order neurons in the medulla with nucleus gracilis/cuneatus.
It forms the medial leminiscus to synapse with third Order neurons on the ventral posterolateral nucleus of thalamus.
What is a Lacunar stroke?
Stroke affecting the arteries supplying the deeper structures.
What is the blood supply to the internal capsule?
Lenticulostriate arteries
How does a stroke of the ACA present?
Supplies the medial surface of frontal lobe. Contralateral limbs, affecting LOWER limbs mainly with motor and sensory impairment.
How does a stroke of the MCA present?
Supplies lateral surface of frontal lobe. Contralateral limb, affecting UPPER limbs mainly with motor and sensory loss.
Homonymous hemianopia, one sided motor and sensory deficit.
What does the posterior inferior cerebellar artery supply?
Choroid plexus and 4th ventricle.
Stroke affecting posterior inferior cerebellar artery?
Loss of medullary function causes dysphagia, dysarthria and vestibular symptoms (due to cranial nerve 8 arising from here)
Why is there macula sparing in stroke?
Middle cerebral artery or posterior cerebral artery that both supplies macula is preserved.
What does Homonymous hemianopia, motor AND and sensory deficit indicate?
Middle cerebral artery stroke.
Homonymous hemianopia AND sensory deficit?
Posterior cerebral artery due to supply to thalamus for sensation.
