The Brainstem

What are the three major parts of the brainstem?

Mesencephalon, pons, and medulla oblongata

Which brainstem structure connects with the spinal cord?

Medulla oblongata

Which brainstem structure connects with the telencephalon?

Pedunculus cerebri

What are the three cerebellar peduncles?

Pedunculus cerebellaris superior, medius, and inferior

What is another name for the inferior cerebellar peduncle?

Corpus restiforme

What is another name for the middle cerebellar peduncle?

Brachium pontis

What is another name for the superior cerebellar peduncle?

Brachium conjunctivum

What ventral midbrain structure is also called the crus cerebri?

Pedunculus cerebri

Which large ventral structure is characteristic of the pons?

Pons

Which peduncle forms the major lateral connection between pons and cerebellum?

Middle cerebellar peduncle

Which paired ventral medullary elevations contain corticospinal fibers?

Pyramids

What is the crossing of corticospinal fibers in the caudal medulla called?

Decussation of pyramids

Which ventrolateral medullary prominence lies lateral to the pyramid?

Olive

Which cranial nerve emerges from the ventral surface of the midbrain?

Oculomotor nerve

Which cranial nerve is the only cranial nerve to emerge dorsally from the brainstem?

Trochlear nerve

Which cranial nerve emerges from the lateral aspect of the pons?

Trigeminal nerve

Which cranial nerve emerges near the midline at the pontomedullary junction?

Abducent nerve

Which two cranial nerves emerge at the cerebellopontine angle?

Facial and vestibulocochlear nerves

Which cranial nerves emerge from the postolivary sulcus?

Glossopharyngeal, vagus, and accessory nerves

Which cranial nerve emerges from the preolivary sulcus?

Hypoglossal nerve

What are the paired dorsal midbrain elevations involved in visual reflex pathways?

Superior colliculi

What are the paired dorsal midbrain elevations involved in auditory pathways?

Inferior colliculi

What dorsal pontine structure overlies the trochlear nerve?

Superior medullary velum

What dorsal pontine elevation is produced by fibers of the facial nerve looping over the abducens nucleus?

Facial colliculus

What dorsal brainstem area contains vestibular nuclei?

Vestibular area

What transverse fibers cross the floor of the fourth ventricle?

Striae medullares

What dorsal medullary swelling overlies the nucleus gracilis?

Gracile tubercle

What dorsal medullary swelling overlies the nucleus cuneatus?

Cuneate tubercle

What triangular area of the floor of the fourth ventricle overlies the hypoglossal nucleus?

Hypoglossal trigone

What triangular area of the floor of the fourth ventricle overlies the dorsal vagal nucleus?

Vagal trigone

What is the caudal point of the fourth ventricle where it narrows into the central canal?

Obex

What groove separates the two sides of the dorsal brainstem and spinal cord?

Dorsal median sulcus

What structure lies lateral to the gracile fasciculus in the dorsal medulla?

Cuneate fasciculus

What are the three major internal components of the brainstem?

Gray matter, white matter, and reticular formation

What are the two major components of brainstem gray matter?

Cranial nerve nuclei and proper nuclei

What are the two major components of brainstem white matter?

Long tracts and proper tracts

What is the basis of the mesencephalon called?

Basis pedunculi or crus cerebri

What is the basis of the pons called?

Pars basilaris pontis

What is the basis of the medulla called?

Pyramis

What is the tegmentum of the mesencephalon called?

Pars tegmentalis mesencephali

What is the tegmentum of the pons called?

Pars tegmentalis pontis

What is the tegmentum of the medulla called?

Pars tegmentalis medullae oblongatae

What is the tectum of the mesencephalon called?

Lamina tecti or lamina quadrigemina

What structure forms the tectum-related roof component of the pons?

Velum medullare superius

What structure forms the tectum-related roof component of the medulla?

Velum medullare inferius

What four functional groups classify cranial nerve nuclei in the brainstem?

Somatomotor, visceromotor, somatosensory, and viscerosensory

What autonomic functional type is represented by visceromotor cranial nerve nuclei?

Parasympathetic

What are the two positional groups of somatomotor cranial nerve nuclei?

Ventrolateral and dorsomedial nuclear groups

Which cranial nerve nuclei form the optomotor group?

Oculomotor, trochlear, and abducens nuclei

What is the main somatic motor nucleus of cranial nerve III called?

Nucleus principalis nervi oculomotorii

Which oculomotor-associated nucleus is named after Perlia?

Nucleus centralis Perlia

Which parasympathetic oculomotor nucleus is also called the Edinger-Westphal nucleus?

Nucleus accessorius nervi oculomotorii

Which nucleus gives rise to the trochlear nerve?

Nucleus nervi trochlearis

Which nucleus gives rise to the abducens nerve?

Nucleus nervi abducentis

Which nucleus supplies motor fibers of the trigeminal nerve?

Nucleus motorius nervi trigeminalis

Which trigeminal nucleus receives spinal-tract sensory input?

Nucleus tractus spinalis nervi trigeminalis

What is another name for the principal sensory nucleus of the trigeminal nerve?

Nucleus pontinus

Which trigeminal nucleus is associated with the mesencephalic tract?

Nucleus tractus mesencephalici nervi trigeminalis

What are the four nuclei of the trigeminal group?

Motor nucleus, spinal trigeminal nucleus, principal sensory nucleus, and mesencephalic trigeminal nucleus

Which nucleus gives rise to the facial nerve?

Nucleus nervi facialis

Which nucleus is shared by the facial and glossopharyngeal-vagus groups?

Nucleus tractus solitarii

Which parasympathetic nucleus belongs to the facial group?

Nucleus salivatorius superior

What are the nuclei of the facial group?

Facial nucleus, solitary tract nucleus, and superior salivatory nucleus

What are the two cochlear nuclei?

Nucleus cochlearis ventralis and nucleus cochlearis dorsalis

What are the four vestibular nuclei?

Superior, inferior, medial, and lateral vestibular nuclei

Which vestibular nucleus is named nucleus vestibularis lateralis?

Lateral vestibular nucleus

Which vestibular nucleus is named nucleus vestibularis medialis?

Medial vestibular nucleus

Which vestibular nucleus is named nucleus vestibularis superior?

Superior vestibular nucleus

Which vestibular nucleus is named nucleus vestibularis inferior?

Inferior vestibular nucleus

What are the main nuclei included in the vestibulocochlear group?

Ventral and dorsal cochlear nuclei plus superior, inferior, medial, and lateral vestibular nuclei

Which branchial motor nucleus belongs to the glossopharyngeal-vagus group?

Nucleus ambiguus

Which sensory nucleus belongs to the glossopharyngeal-vagus group?

Nucleus tractus solitarii

Which parasympathetic nucleus belongs to the glossopharyngeal group?

Nucleus salivatorius inferior

Which parasympathetic nucleus belongs to the vagus nerve?

Nucleus dorsalis nervi vagi

What are the nuclei of the glossopharyngeal-vagus group?

Nucleus ambiguus, nucleus tractus solitarii, inferior salivatory nucleus, and dorsal vagal nucleus

Which two nuclei belong to the accessory nerve group?

Nucleus ambiguus and nucleus spinalis

Which nucleus gives rise to the hypoglossal nerve?

Nucleus nervi hypoglossi

Which proper nuclei are located in the medulla oblongata?

Nucleus gracilis, nucleus cuneatus, inferior olivary group, and accessory cuneate nucleus

Which proper nuclei are located in the pons?

Pontine nuclei and accessory acoustic nuclei

Which proper nuclei are located in the mesencephalon?

Red nucleus, substantia nigra, superior colliculus, and inferior colliculus

What is another name for the nucleus gracilis?

Goll nucleus

What is another name for the nucleus cuneatus?

Burdach nucleus

Which pathway has the nucleus gracilis and nucleus cuneatus as relay stations?

Dorsal funiculus-medial lemniscus pathway

Which nucleus receives input from the fasciculus gracilis?

Nucleus gracilis

Which nucleus receives input from the fasciculus cuneatus?

Nucleus cuneatus

What are the components of the inferior olivary group?

Principal, medial accessory, and dorsal accessory olivary nuclei

Which tract connects the inferior olive to the cerebellum?

Tractus olivocerebellaris

Which tract provides rubro-olivary connections to the inferior olive?

Tractus tegmentalis centralis

Which descending tract connects the inferior olive with the spinal cord?

Tractus olivospinalis

Which ascending tract connects the spinal cord with the inferior olive?

Tractus spinoolivaris

What is another name for the accessory cuneate nucleus?

Monakow nucleus

Which tract arises from the accessory cuneate nucleus?

Tractus cuneocerebellaris

Which nuclei receive corticopontine fibers?

Nuclei pontis

Which tract carries fibers from cerebral cortex to pontine nuclei?

Tractus corticopontinus

Which tract carries fibers from pontine nuclei to the cerebellum?

Tractus pontocerebellaris

What are the accessory acoustic nuclei of the pons?

Nucleus corporis trapezoidei, superior olive, and nucleus lemnisci lateralis

Which nucleus belongs to the trapezoid body?

Nucleus corporis trapezoidei

Which auditory relay nucleus lies in the pons and is named for the olive?

Oliva superior

Which auditory relay nucleus is associated with the lateral lemniscus?

Nucleus lemnisci lateralis

Which midbrain nucleus receives corticorubral fibers?

Nucleus ruber