ANAT2004 Neuroanatomy - Brainstem Lecture Review

Fill-in-the-blank practice flashcards covering brainstem neuroanatomy, cranial nerve nuclei, internal fiber tracts, extrapyramidal pathways, and brainstem blood supply based on lecture notes.

The three major embryological divisions of the brainstem seen on a medial sagittal section are the mesencephalon, metencephalon, and __________.

myelencephalon

The longitudinal groove on the floor of the fourth ventricle that separates medial motor areas from lateral sensory areas is the __________.

sulcus limitans

During embryonic development of the neural tube, sensory neurons develop in the alar plate while motor neurons originate in the __________ plate.

basal

All ascending general sensory fibers run from the spinal cord through the brainstem to reach the __________.

thalamus

The network of white matter fibers ascending through the reticular formation to regulate sleep, arousal, and alertness is known as the __________.

Ascending Reticular Activating System (ARAS)

In the ventral tier of the lateral thalamic nuclei, the medial geniculate nucleus relays auditory input, while the lateral geniculate nucleus relays __________ input.

visual

The ventral posteriolateral (VPL) nucleus receives general sensation from the body, whereas the ventral posteriomedial (VPM) nucleus receives general sensation from the __________.

head

The medulla oblongata measures approximately $3\,\text{cm}$ in length, whereas the pons and midbrain each measure __________.

$$2.5\,\text{cm}$$

The rostral portion of the roof of the rhomboid fossa is formed by the superior cerebellar peduncles bridged by the __________.

superior medullary velum

On the floor of the fourth ventricle, the facial colliculus is an elevation formed by axons of CN VII looping around the nucleus of __________.

CN VI (abducens nerve)

The landmark at the caudal apex of the rhomboid fossa where the fourth ventricle narrows into the central canal is the __________.

obex

At the decussation of the pyramids in the caudal medulla, approximately __________ of corticospinal fibers cross over to form the lateral corticospinal tract.

$$90\%$$

The olivary eminences located laterally on the anterior surface of the medulla mark the position of the underlying __________ nuclei.

inferior olivary

Pontocerebellar fibers originate from scattered pontine nuclei, decussate, and enter the cerebellum via the __________ cerebellar peduncles.

middle

The gray matter surrounding the central canal/aqueduct of the midbrain that is involved in pain-inhibition pathways is the __________.

periaqueductal gray (PAG)

The corpora quadrigemina on the dorsal midbrain consist of the superior colliculi for visual/pupillary reflexes and the inferior colliculi for the __________ pathway.

hearing

Degeneration of dopamine-producing neurons within the darkly pigmented __________ in the midbrain leads to Parkinson disease.

substantia nigra

The rubrospinal tract originates in the red nucleus of the midbrain and promotes goal-directed flexion of the __________ limbs.

upper

Medial brainstem motor pathways (vestibulospinals, reticulospinals, tectospinals) descend in the anterior columns of the spinal cord to excite __________ muscles for posture and balance.

extensor

A patient with damage to cortical/pyramidal pathways but an intact brainstem exhibits __________ posturing, characterized by upper limb flexion and lower limb extension.

decorticate

In decerebrate rigidity, both upper and lower limbs are extended because damage extending into the midbrain abolishes the function of the __________ tract.

rubrospinal

The posterior inferior cerebellar artery (PICA) branches directly off the __________ artery.

vertebral

The Anterior Inferior Cerebellar Artery (AICA) and Superior Cerebellar Artery (SCA) both branch directly off the __________ artery.

basilar