Exam One - Brainstem/Medulla Flashcards
What are the 3 primary vesicles?
Prosencephalon
Mesencephalon
Rhombencephalon
What are the two primary flextures?
cervical
cephalic
Where is the cervical flexure?
Separates the spinal cord and the rhombencephalon
Where is the cephalic flexture?
in the mesencephalon
What are the 5 secondary vesicles?
Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon
What are the 2 secondary flexures?
Pontine
telencephalic
Where is the pontine flexure?
divides hindbrain into metencephalon and myelencephalon
Where is the telencephalic flexure?
divides prosencephalon into diencephalon and telencephalon
Describe how CSF moves through the ventricles
lateral ventricles -> interventricular foramen -> third ventricle -> cerebral aquaduct -> 4th ventricle -> central canal
Contents of the brainstem
White matter
Gray Matter
Major afferent and efferent fiber connections with the cerebellum
Reticular Formation (medial and lateral nuclear components)
White matter in the brainstem
1 - ascending sensory fibers that originate from SC neurons and DRG neurons
2 - descending motor fibers that originate from neurons of the telencephalon and diencephalon
3 - ascending and descending fibers that originate from brainstem neurons
Grey matter in the brainstem:
Sensory and motor nuclei of cranial nerves
In the Brainstem, there are major ___________ and ____________ fiber connections with the _____________
afferent, efferent, cerebellum
Reticular Formation (medial and lateral nuclear components) in the brainstem
- Ascending reticular activating system (RAS)
- Central pattern generators
- Pain modulation centers
- nuclear centers
Reticular formation central pattern generators
networks of neurons that generate stereotypes, rhythmic motor behaviors such as walking, running, swimming, breathing, chewing, certain eye movements, shivering, scratching
reticular formation pain modulation centers
periaqueductal gray of the midbrain
reticular formation nuclear centers
control/modulate visceral special senses and reflexes related to these senses: cardiac and respiratory centers
Important ventral structures
crus cerebri, basilar pons, pyramids
important external features of the ventral surface
crus cerebri, basilar pons, anterior median fissure, pyramid, olive, pyramidal decussation
Parts of _____ and __________ form the floor of the 4th ventricle
pons, medulla
Features on the dorsal surface of the brainstem and the rhomboid fossa
obex
sulcus limitans
obex
the most caudal point of the 4th ventricle, as it narrows and communicates with the central canal of the SC
What features separates the open and closed medulla?
sulcus limitans
sulcus limitans
important landmark for functional anatomy of brainstem nuclei, separates the cranial nerves’ motor and sensory nuclei, motor nuclei are more MEDIAL and sensory nuclei are LATERAL
What continues caudally and rostrally with the medullar oblongata?
caudally - spinal cord at the level of foramen magnum
rostrally - pons
The medulla is __________. The portion that is caudal to the 4th ventricle is ___________. The portion located within the 4th ventricle is ______________.
subdivided, closed, open
What are the contents of the medullar oblongata?
- cranial nerve nuclei 8-12
- components of CN 5
- corticospinal and dorsal column.medial lemniscus
- dorsal column nuclei (nucleus gracile and cuneate)
- ascending and descending spinal cord tracts
- cardiac and respiratory centers
- nuclei related to cerebellar function - nuclei specific to the reticular formation
Alar and basal plates shift in which ventricle?
4th
cell groups medial to the sulcus limitans are ______, cell groups lateral to the sulcus limitans are _____________
motor, sensory
At what level does pyramidal decussation occur?
junction of medulla and central cord
At what level does sensory decussation occur?
closed medulla
What branches off the vertebral artery supply the medulla?
-anterior spinal artery
- posterior spinal artery
- Post. inf. cerebellar a. (PICA)
What branches off the basilar artery supply the medulla?
- ant. inf. cerebellar a (AICA)
blood supply of closed medulla (under obex)
-PICA
-PSA
-ASA
-VA
blood supply of open medulla
- PICA
- VA
-ASA
blood supply of medulla right under pons
- AICA
-PICA
-VA
-ASA
Which CN originate in medulla?
9,10,11,12
CN 9 damaged
- glossopharyngeal
- ipsilateral loss of pharyngeal sensation
CN 10 damaged
- vegus
- ipsilateral palatal weakness
CN 11 damaged
- spinal accessory
- ipsilateral weakness in trap and SCM muscles
CN 12 damaged
- hypoglossal
- ipsilateral weakness in the tongue
