9. Cerebellum, Basal Ganglia, Extrapyramidal System Flashcards
(38 cards)
What do the extrapyramidal systems control?
Voluntary movement
What does the corticobulbar pathway control?
Muscles in the head and neck
Give the corticobulbar pathway
- Arise from the lateral aspect of the primary motor cortex
- Fibres converge and pass through genu of the internal capsule
- Go through pyramids of the medulla
- Synapse of motor nuclei of cranial nerves
- Lower motor neurons to muscles of head and neck
Which cranial nerves are not innervated bilaterally?
VII below the eyes
XII
Give the corticospinal pathway
- Cortex
- Posterior limb of internal capsule
- 85% decussate in the medulla and enter the lateral corticospinal tract
Terminate in the ventral horn - 15% remain ipsilateral in the anterior corticospinal tract
Decussate and terminate in the ventral horn
What are the symptoms of an upper motor neuron lesion?
Ipsilateral: weakness, hypertonicity, hyperreflexia, clonus, babinski’s sign
What happens in an upper motor neuron lesion to the facial nerve?
Face droops below eye on the contralateral side
What are the symptoms of a lower motor nerve lesion?
Ipsilateral: paralysis, muscle wasting, fasciculations, hypotonicity, hyporeflexia
What happens in a lower motor neuron lesion to the facial nerve?
Facial muscles are damaged above and below eyes
Where is the cerebellum situated in the skull?
Posterior cranial fossa
What membrane surrounds the cerebellum?
Tentorium cerebelli
What does the superior cerebellar peduncle connect the cerebellum to?
Midbrain
What does the middle cerebellar peduncle connect the cerebellum to?
Pons
What does the inferior cerebellar peduncle connect the cerebellum to?
Medulla
What is the name of the midline of the cerebellum?
Vermis
What are the lobes of the cerebellum?
Anterior
Posterior
Flocculonodular
What are the functional divisions of the cerebellum?
Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum
What does the vestibulocerebellum control?
Balance
What is the main nucleus in the vestibulocerebellum?
Fastigial
What problems are associated with the vestibulocerebellum?
Problems with walking, posture and eye movements
What does the spinocerebellum control?
Muscle tone and posture
What are the main nuclei in the spinocerebellum?
Globose and emboliform
What does the cerebrocerebellum control?
Muscle coordination, planning movement
What is the main nucleus in the cerebrocerebellum?
Dentate
