Brainstem and floor of the IVth ventricle Flashcards
What is the rhomboid fossa?
diamond shaped floor of the IVth ventricle
What is the median sulcus?
divides the rhomboid fossa into triangular left and right halves
On each side, what extends towards the lateral margin of the brainstem?
Lateral recess extends towards the lateral margin of the brainstem and is in continuity, through a small lateral aperture (foramen of Luschka) with the subarachnoid space of the cerebellopontine angle
What is the foramen of Magendie?
The foramen of Magendie (also called median aperture) is one of the foramina in the ventricular system and links the fourth ventricle and the cisterna magna
What is the foramen of Luschka?
The foramen of Luschka is a natural aperture between the fourth ventricle and the subarachnoid space at the cerebellopontine angle.
What is the facial colliculus?
round swelling caused by the fibres of the facial nerve (CN CN VII) in the substance of the pons curving around the nucleus of the abducens nerve (CN VI) at the level of the superior fovea
What are the medullary striae?
aberrant ponto-cerebellar fibres passing from the pons t the cerebellum. They divide the floor of the IVth ventricle into a rostral pontine half and caudal medullary half
What is the locus coeruleus?
bluish-grey pigmented noradrenergic cells under the ependyma at the rostral half of the sulcus limitans
What is the hypoglossal trigone?
medial triangular area overlying the hypoglossal (CN XII) nerve nucleus
What is the vagal trigone?
intermediate triangular area overlying the vagus (CN X) nerve nucleus
What is the vestibular trigone?
lateral triangular area overlying the vestibulocochlear (CN VIII) nerve nucleus
What is the obex?
inferior apex of the rhomboid fossa
What is the area postrema?
a small tongue-shaped area immediately rostro-lateral to the obex - site commonly associated with nausea control (chemoreceptive trigger zone for the emetic response)
