Term
| what are the three sections of the brainstem? |
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Definition
- midbrain aka mesencephalon
- pons aka metencephalon
- medulla oblongata aka myelencephalon |
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Term
| boundaries of the midbrain: |
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Definition
- Posterior commissure of diencephalon
- Line drawn immediately caudal to the site of emergence of CN IV (trochlear n.)
Superior anterior (ventral) boundary
Caudal to mamillary bodies of hypothalamus
Inferior anterior (ventral) boundary
Superior pontine sulcus at the pontomesencephalic junction |
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Term
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Definition
Superior posterior (dorsal) boundary
Caudal to site of emergence of the trochlear n. (CN IV)
Inferior posterior (dorsal) boundary
Stria medullaris on the floor of the fourth ventricle
Superior anterior (ventral) boundary
Superior pontine sulcus at the pontomesencephalic junction
Inferior anterior (ventral) boundary
Inferior pontine sulcus at the pontomedullary junction |
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Term
| boundaries of medulla oblongata: |
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Definition
Superior posterior (dorsal) boundary
Stria medullaris of the fourth ventricle
Inferior posterior (dorsal) boundary
Plane just rostral to C1 ventral root emergence and caudal to the decussation of the pyramids
Superior anterior (ventral) boundary
Inferior pontine sulcus at the pontomedullary junction
Inferior anterior (ventral) boundary
Line drawn just caudal to the decussation of the pyramids |
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Term
| important structures of the midbrain: |
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Definition
- cerebral peduncles (crus cerebri, pes pedunculi)
- corticopontine, corticospinal, and corticobulbar tracts
- interpeduncular fossa
- oculomotor nerve (CN III) |
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Term
| important structures of the pons: |
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Definition
Basilar sulcus
Basal portion of the pons
Superior pontine sulcus (isthmus)
Inferior pontine sulcus
CNs VI (abducens), VII (facial), VIII (vestibulocochlear, auditory, statoacoustic ) |
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Term
| important structures of medulla: |
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Definition
Inferior pontine sulcus
CNs VI (abducens n.), VII (facial n.), VIII(vestibulochochlear n.)
Pyramids
Decussation of the pyramids
Anterior median fissure
Preolivary sulcus
CN XII (Hypoglossal n.)
Postolivary sulcus
CNs IX (glossopharyngeal n.), X (vagus n.) XI (bulbar part of the accessory n.)
Inferior olivary eminence |
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Term
| important structures of midbrain laterally: |
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Definition
Superior and inferior colliculi of the tectum (Corpora quadrigemina)
The optic and auditory reflex centers, respectively.
Lateral lemniscus (auditory pathway structure to inf. colliculus)
CN IV (Trochlear n.)
Brachium of the superior colliculus
Brachium of the inferior colliculus |
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Term
| important structures of the pons laterally: |
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Definition
Middle cerebellar peduncle (brachium pontis)
Motor and sensory root of CN V (trigeminal n.)
CN VII (facial n.) and Nervus intermedius of CN VII.
CN VIII (vestibulocochlear n.) |
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