Exam #1: Introduction to the Brainstem Flashcards
What are the three structures of the brainstem?
1) Midbrain
2) Pons
3) Medulla
Where is the cerebral aqueduct in relation to the brainstem?
Between the tectum & tegmentum of the midbrain
What is the anterior median fissure?
Ventral fissure of the brainstem
What is the posterior median sulcus?
Dorsal sulcus of the braimstem
Where is the 4th ventricle in relation to the brainstem?
Posterior to the pons i.e. rostral medulla
What is the rule of four?
12 Cranial Nerves
3 Parts of the brainstem
= 4 CN per section of the brainstem
Where do CN I & II come from? What about III & IV?
- Brain itself, NOT the brainstem
- III= ventral midbrain
- IV= dorsal midbrain
Where do CN V, VI, VII, & VIII origiante?
Pontomedullary junction
Where do CN IX, X, XI, & XII originate?
Brainstem
What is the infandibulum? Where is it located? What kind of symptoms are seen with a tumor of the infandibulum?
Pituitary stalk–the optic chiasm is directly over
Tumor= changes in vision
What CN originates inferior to the Corpora Quadrigemini?
CN IV
What is the rhomboid fossa? What is contained in the Rhomboid fossa?
4th ventricle
Facial colliculus–CN VII
What is the hypoglossal trigone?
This is where the hypoglossal nerve comes off the brainstem; the hypoglossal nucleus is deep to the trigone
What is the vagal trigone?
This is where the vagus nerve comes off the brainstem; the vagal nucleus is deep to the trigone
What are the Gracile Tubercle & Cuneate Tubercle?
Swelling in the medulla from the Facisuclus Gracilis (medial) & Fasiculis Cuneatus (lateral)
What is the sulcus limitans?
In the floor of the fourth ventricle, the sulcus limitans separates the cranial nerve motor nuclei (medial) from the sensory nuclei (lateral)
- Between= both
*Separates midline structure from lateral structures
What is the open medulla?
Where the 4th ventricle becomes visible on cross-section in the rostal medulla/ near the ponto-medullary junction
What is the function of the basilar pons?
Motor function
What is the function of the tegmentum?
Multisynaptic network of neurons that is involved in many unconscious homeostatic and reflexive pathways.
What is the function of the tectum?
Corpora Quadragemi
Superior= auditory
Inferior= hearing
What is the hallmark for the medulla? What tells you if you’re rostral or caudal?
Inferior olivary nucleus= hallmark for the medulla
*Open vs. closed i.e. 4th ventricle tells you if you’re rostral or caudal
What is the inferior cerebellar peduncle?
Connects the spinal cord and medulla oblongata with the cerebellum
What is the middle cerebellar peduncle?
Connect the cerebellum to the pons
What is the superior cerebellar peduncle?
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What is the periaqueductal gray? What is the function?
Gray matter that surrounds the cerebral aqueduct in the midbrain; functions to transmit pain signals
What are the four CN that are both motor & sensory?
CN V
CN VII
CN IX (Glossopharyngeal)
XN X (Vagus)
Describe the CN orientation around the olive.
Medial= CN XII Lateal= CN IX, X, XI
Where is the nucleus located for CN XI?
In the spinal cord–“Spinal Accessory”
