Brainstem Flashcards
• Recognize the three broad functions: conduit, cranial nerve and integrative.
- Conduit: information goes to the cortex and spinal cord through the brainstem, white matter tracts.
- Cranial nerves: head’s version of spinal nerves, but also nerves for taste, equilibrium, eye muscles etc.
- Integrative functions: complex motor patterns, cardiorespiratory control (Reticular formation, central core in brainstem.
_____ is the tissue anterior to ventricle.
Tegmentum
______ is the tissue posterior to ventricle.
Tectum
Three subdivisions of the brainstem…
Midbrain
Pons
Medulla
Name 4 structures of Anterior Medulla….
- Pyramidal decussation
- Olive (Lateral to pyramids)
- Anterior median fissure
- Anterolateral sulcus (between olive and Pyramid)
Name 8 structures of Posterior Medulla….
- Obex (looks like a pinhole)
- Gracile tubercle (Just lateral to obex)
- Cuneate Tubercle (lateral to Gracile tubercle)
- Posterior median sulcus
- Sulcus limitans
- Hypoglossal trigone (above obex)
- Vagal trigone (Lateral to Hypiglossal trigone)
- Facial Colliculus (above trigones)
Name 4 structures of Anterior Pons…
- Basal Pons
- CN V & VI
- CN VII (motor, sensory & intermediate roots)
- CN VIII (Vestibulocochlear)
Name 3 structures of Posterior Pons….
- Middle cerebellar peduncle (Lateral)
- Superior cerebellar peduncle (Medial to MCP)
- Lateral Lemniscus?
Name 6 structures of Midbrain…
- Cerebral aqueduct (Ends at 4th ventricle)
- Superior Colliculus (Superior to start of aqueduct)
- Inferior Colliculus (Inf to SC)
- Cerebral peduncles
- CN III & IV
- Inferior Branchium
Name 3 main fiber tract locations in brainstem…
- Coritcospinal tract (anterior)
- Spinothalamic tract (Anterolateral)
- Medial lemniscus (More variable in location)
_______ extends form caudal edge of pyramidal decussation to obex.
Caudal (Closed) medulla
*Rostral medulla is obex and up?
What unique structures would you expect to see in a cross section of the caudal medulla?
- Central canal
- Graclie and Cunteate Nuclei
- Internal arcuate fibers form medial lemniscus
- Pyramidal decussation
What unique structures would you expect to see in a cross section of the Rostral Medulla?
- fourth ventricle
- Inferior Olivary nuclei
- CN XII
- Internal arcuate fibers from IO to ICP
- Pyramids
What structures would you expect to see in the Caudal Pons?
- Inferior cerebellum peduncle: mostly within cerebellum at this level
- Middle cerebellar peduncle attaches pons to cerebellum
- ML: horizontal with feet lateral (compare to rostral medulla)
- Fourth ventricle present
What structures would you expect to see in the Rostral Pons?
- Superior cerebellar peduncle
- ML: horizontal with feet lateral, approaches STT
- Small ventricle space: at opening of aqueduct
What structures would you expect to see in the Caudal Midbrain?
- Inferior colliculi
- IV
- Decussation of SCP
What structures would you expect to see in the Rostral Midbrain?
- Superior colliculi
- III
- Red nucleus
- Substantia nigra
What supplies blood to Anterior and Medial brainstem?
Perforating branches of the vertebral-basilar system.
What supplies blood to lateral brainstem and Cerebellum?
Circumferential Arteries
There are ____ types of nerve fibers in the brainstem.
6
*Note no cranial nerve has all 6 types.
Which cranial nerves are motor axons for somatic skeletal muscle (Somatic motor fiber)?
III, IV, VI, XII
Which Cranial nerves are special sensory fibers?
I, II & VIII
Which Cranial nerves are branchiomeric nerves? (Contain several components that all innervate branchial muscle)
V, VII, IX, X & XI
