Neuro - Brainstem and Cranial Nerves Flashcards
What are the sections of the brainstem?
Mid brain
Pons
Medulla
What pathways pass through the brainstem?
All pathways to and from the cerebral cortex
How is the cerebellum connected to the brainstem?
it is attached to the pons via 3 cerebella peduncles (white fibre tracts)
What cranial nerves does the brainstem contain?
3-12 except for 11
What is the horizontal section of the midbrain?
Posteriorly, we have the tectum (roof) and the tegmentum in the centre, with the ventricular system separating the two sections. Then anteriorly, we have two sections of the base.
What are cerebral peduncles?
These bring pathways (corticospinal and corticobulbar) down from the cerebral cortex - not to be confused with the cerebellar peduncles
What does the mid brain contain?
Cerebral peduncles
Aqueduct
Superior (visual) colliculi
Inferior (auditory) colliculi
What does the pons contain?
4th ventricle
Middle cerebellar peduncle
Cranial nerves V, VI, VII, VIII
What is the open medulla?
Upper medulla
What does the open medulla contain?
No roof to the 4th ventricle due to no cerebellum
Contains inferior olivary nucleus
What is the closed medulla?
Lower medulla
What does the closed medulla contain?
4th ventricle has tapered down and formed the central canal so is surrounded by neural tissue therefore closing the medulla.
Dorsal columns are found here
Visible decussation of the pyramids
Where is decussation of the medulla found?
Closed lower medulla
What is the medulla?
Rostral continuation of the spinal cord
What does the medulla contain on its anterior surface?
Pyramids with tracts from the cerebral cortex to the spinal cord.
What does the posterior surface of the medulla contain?
Dorsal column that are either open or closed dependent on the presence of the cerebellum.
From what 2 arteries does the brainstem blood supply come from?
Anterior and posterior arteries
Where is the anterior artery derived from?
Internal carotid artery
Where is the posterior artery derived from?
Vertebrobasilar system (main supply for brainstem)
What are GSA neurones?
General somatic afferent - general sensation from the skin, muscle and joints of the head and neck.
What are GSE neurones?
General somatic efferent - Fibres innervate skeletal muscle
What are GVA neurones?
General visceral afferent - afferent from organs of head neck thorax and abdomen.
What are GVE neurones?
Fibres in the preganglionic parasympathetic neurones to the cranial, thoracic and abdominal viscera.
What are SSA neurones?
Special somatic afferent - fibres carry special senses of hearing and balance
What are SVA neurones?
Special visceral afferent - fibres carry taste sensation from tongue
What are SVE neurones?
Special visceral efferent - innervate skeletal muscle of the jaw, face, larynx and pharynx.
What cranial nerves emerge from the midbrain?
III, IV
What cranial nerves emerge from the pons?
V, VI, VII, VIII
What cranial nerves emerge from the medulla?
IX, X, XII
