Brain Stem External Features Flashcards
How is the brain stem connected to the cerebellum?
By the 3 peduncles :
- SCP
- MCP
- ICP
Superior cerebellar peduncle connects what to what?
Cerebellum to the midbrain
Middle cerebellar peduncle connects what to what?
Cerebellum to pons
ICP connects what to what?
Cerebellum to medulla
Waite matter of the Brian’s team includes?
Longitudinal fibers
Horizontal fibers
Longitudinal fibers of Brian stem include?
Descending tracts
Ascending tracts
Association tract called medial longitudinal bundle
Horizontal fibers of brain stem include?
- Decussations
- Arcuate fibers in the medulla
Grey matter of brain stem include?
- Cranial nerve nuclei
- Olivary nuclei in medulla
- Pontine nuclei in their pons
- Red nucleus in the midbrain
What is reticular formation?
A core of mixed grey and white matters lying within the brain stem
The medulla obloingata extends from where to where?
Spinal cord to pons
What 3 elevations does the medulla oblongata have on its ventral surface?
Pyramid
Olive
ICP
The olive, pyramid and ICP are elevations on the ventral surface of the medulla oblongata on each side of what?
The anterior median fissure
List the 3 elevations on each side of anterior median fissure medial to lateral
Pyramid - olive - ICP
What is the pyramid made by?
Corticospinal tract
What does the pyramid form?
Motor decussation in the lower medulla
What is the olive made by?
Inferior olivary nucleus
What is the ICP made of?
Fibers connecting the medulla and cerebellum
What nerve attachments does the medulla oblongata show?
Last 4 cranial nerves : XII, IX, X, XI
Where on the medulla is nerve XII attached to?
Anterolateral sulcus ( between the pyramid and olive)
Where on the medulla are the IX, X, XI cranial nerves attached?
To the posterolateral sulcus ( between the olive & ICP)
Where is basis Pontis located?
- The middle of the pons
- It projects anteriorly
What does the basis pontis show?
- Sulcus for the basilar artery
- Transverse grooves between bundles of transverse fibers
What nerves does the pons give attachment to?
V, VI, VII, VIII
Where on the pons is the nerve V attached?
- To the junction of basis pontis and MCP
- Closer to upper border by 2 roots
For the Trigeminal nerve comment on the nerves
Sensory : Large, lateral
Motor : Small, medial
Where is nerve VI located on the pons?
- Lower border of pons, just above pyramid
Where on the pons is nerve VII located?
Cerebello-pontine angle ( Between MCP & ICP)
Comment on the roots of the facial nerve
Motor : Large, medial
Sensory nervous intermedius : Small, lateral
Where is nerve VIII attached?
Cerebello-pontine angle, lateral to VII
Comment on the roots of vestibulocochlear nerve
Vestibular- Medially
Cochlear - laterally
Where is the oculomotor nerve?
It emerges from the medial side of the cerebral peduncle
What structures wind around the cerebral peduncle?
- Optic tract
- Trochlear nerve
- Posterior cerebral artery
- Basal vein
What are the boundaries of the interpeduncular fossa?
Anteriorly - optic chiasma
Anterolaterally - optic tract
Posterolaterally - cerebral peduncle
Posteriorly - Upper border of pons
What are the contents of the interpeduncular fossa?
- Tuber cinereum
- Mammillary bodies
- Posterior perforated substance
- Oculomotor nerve
What is the Tuber cinereum?
- A convex mass of grey matter
- The median eminence of hypothalamus
How is the tuber cinereum connected with the posterior lobe of the pituitary gland?
Via the infuldibulum
What are the mammillary bodies?
2 rounded nuclei of hypothalamus
What is the posterior perforated substance?
An area of grey matter showing small holes pierced by the central branches of posterior cerebral artery
Where does the oculomotor nerve emerge from?
Medial surface of cerebral peduncle
Where is the anterior perforated substance located?
- Lateral to optic chiasma
- Pierced by central branches of anterior and middle cerebral arteries
The lower part of the back of medulla oblongata shows 3 elevations on each side of what?
Posterior median sulcus
What are the 3 elevations on the lower part of back of the medulla oblongata?
- Gracile fasciculus (tract) ending on gracile tubercle (nucleus)
- Cuneate fasciculus ending in cuneate tubercle
- ICP
The upper part of the medulla oblongata forms what?
Lower part of the floor of 4th ventricle
What is the base of the upper part of the back of medulla shoe rated from the pons with?
Medullary stria
What is the apex of the upper part of the back of the medulla continuous with?
Central canal
What is the base of the back of the pons made of?
Medullary stria
The apex of the back of pons is continuous with?
Cerebral aqueduct of sylvius
