Neuro - Fall Exam 2

Most of the brain stem consists of ___ matter

White

The brain stem consists of what structures (from inferior to superior)

Medulla oblongata, pons, midbrain

Base of the brain stem

Medulla oblongata

The medulla is a control center for vital involuntary reflexes such as:

Swallowing, vomiting, sneezing, coughing, cardiovascular & respiratory activity

The junction between the medulla and pons has a prominent sulcus on the ___ side

Ventral

Sulcus on anterior brain stem separating the medulla from the pons

Pontomedullary sulcus

The caudal 2/3 medulla contains the continuation of the

Central canal

The widest portion of the ___ ventricle is found at the Pontomedullary junction

Fourth

CSF flows from the fourth ventricle to the subarachnoid space of the brain through the

Foramen of Luschka

The lateral walls of the rostral fourth ventricle are made up of the

Superior & inferior cerebellar peduncles

Eminences on ventral side of medulla

Pyramid

Pyramid of the medulla consists of ___ fibers

Corticospinal

Prominent oval swelling located laterally on the medulla

Olive

Where corticospinal tracts cross at the base of the ventral medulla

Pyramidal decussataion

Ridge on medulla that marks position of dorsal Spinocerebellar tracts

Tuberculum cinereum

Tubercles on dorsal side of rostral medulla where dorsal column medial lemniscus pathway terminates

Gracile & cuneate

Gracile is the ___ tubercle; cuneate is the ___ tubercle

Medial; lateral

__ cranial nerves are attached to the medulla & Pontomedullary junction

7

Cranial nerve emerging from the Pontomedullary junction most medially

Abducens (VI)

Cranial nerve emerging from Pontomedullary junction most laterally

Vestibulocochlear (VIII)

Cranial nerve emerging from Pontomedullary sulcus between the two other nerves

Facial (VII)

Cranial nerves emerging between olive & tuberculum cinereum

IX, X, XI

Cranial nerve emerging along ventral arterial sulcus between pyramid & olive

Hypoglossal (XII)

Rounded region of the brain stem between the midbrain & medulla

Pons

Main function of the pons

Modify respiratory output of medulla; connect cerebellum to rest of brain

Connects pons to cerebellum

Middle cerebellar peduncle

Connects medulla to cerebellum

Inferior cerebellar peduncle

Shallow groove along the midline of the ventral surface of the pons

Basilar sulcus

Cranial nerve emerging between pons and the middle cerebellar peduncle

Trigeminal (V)

The dorsal portion of the pons is called the

Tegmentum

The tegmentum contains all ___ tracts

Ascending & descending

The dorsal surface of the pons is formed by the floor of the

Fourth ventricle

The ventral surface of the midbrain extends from the pons to the

Mammillary bodies of the diencephalon

Columns of white matter on either side of the midbrain

Basis peduncul

The basis pedunculi consists of ___ fibers

Corticospinal, corticobulbar, corticopontine

Deep depression between the two basis pedunculi of the midbrain

Interpeduncular fossa

Cranial nerve emerging from side of interpeduncular fossa of the midbrain

Oculomotor (III)

The lateral surface of the midbrain is formed by the

Cerebral peduncle

The Tectum of the midbrain is formed by two ___ and two ___

Superior colliculi; inferior colliculi

The superior colliculi of the midbrain controls

Ocular movement

The inferior colliculi of the midbrain controls

Hearing

Cranial nerve emerging from midbrain immediately caudal to the inferior colliculus

Trochlear (IV)

The basilar section of the brain stem contains ___ structures

Motor

The tegmentum section of the brain stem contains ___ tracts

Ascending sensory

Longitudinal section of the midbrain posterior to the tegmentum

Tectum

Cranial nerves that also supply visceral organ, sensory & motor innervations of the neck, chest, and most of the abdominal organs (not the pelvis)

IX, X

Cranial nerves are numbered in ___ sequence

Rostrocaudal

Only cranial nerve to emerge from the dorsal surface of the brain stem

IV

Collection of neuronal cell bodies in the brain stem that connect or give rise to cranial nerves

Cranial nerve nuclei

Afferent sensory fibers enter the pons via the ___ nerve and terminate at the ___

Trigeminal; trigeminal sensory nucleus

Afferent fibers detecting where the body is in space

Proprioceptive

Proprioceptive fibers run through the ___ nerve & terminate in ___ in the medulla

Vestibulocochlear; vestibular & cochlear nuclei

Afferent visceral fibers terminate in the ___ of the medulla

Nucleus solitarius

Somatic efferent cell column sends motor fibers to cranial nerves ___

III, IV, VI, XII

Efferent nuclei branchiomotor cell column sends motor fibers to cranial nerves ___

V, VII, IX, X, XI

Efferent nuclei parasympathetic cell column sends parasympathetic fibers to cranial nerves ___

III, VII, IX, X

Muscle that abducts the eye

Lateral rectus

Muscle that adducts the eye

Medial rectus

Muscle that moves the eye up

Superior rectus

Muscle that moves the eye down

Inferior rectus

Muscle that moves the eye down & out

Superior oblique

Muscle that moves the eye up & out

Inferior oblique

Cranial nerves controlling eye movement

III, IV, VI

Cranial nerve responsible for moving the eye down & out

Trochlear (IV)

Cranial nerve responsible for abducting the eye

Abducens (VI)

The medial columns of the brain stem are ___; the lateral columns of the brain stem are ___

Motor; sensory

CN I

Olfactory

The olfactory nerve rests upon the

Cribriform plate

The olfactory nerve originates from the

Forebrain

The olfactory nerve terminates at the

Olfactory bulb

Olfactory nerve function

Smell

The olfactory nerve Innervates the

Olfactory epithelium

Only sensation that is not relayed through the thalamus

Olfaction

CN II

Optic

The optic nerve originates in the

Forebrain

The optic nerve terminates at the

Lateral geniculate nucleus

Optic tracts must cross at the ___ before they terminate

Optic chiasm

Optic nerve function

Vision & pupillary light reflex

The optic nerve Innervates the

Retina

CN III

Oculomotor

Motor cell bodies of the oculomotor nerve originate in the

Oculomotor nucleus

Parasympathetic cell bodies of the oculomotor nucleus originate at the

Edinger-Westphal nucleus

Oculomotor nerve function

Eyeball movement, pupil constriction, pupil accomodation

The oculomotor nerve Innervates

Rectus muscles, inferior oblique, Levator palpebra superioris, sphincter pupillae, ciliary muscle

CN IV

Trochlear

Trochlear nerve cell bodies originate in the

Trochlear nucleus

Trochlear nerve function

Eye movements (depress, abduct, or intort)

The trochlear nerve Innervates the

Superior oblique muscle

Cranial nerve with the longest intracranial course (most likely to be affected by hydrocephalus)

Trochlear (IV)

CN V

Trigeminal

Motor cell bodies of the trigeminal nerve originate in the

Trigeminal motor nucleus

Trigeminal sensory cell bodies originate at the

Trigeminal sensory nucleus

Trigeminal nerve function

Open & close mouth, tympanic membrane tension, corneal reflex, cough/sneeze reflex, jaw jerk reflex, general sensation

Sensor fibers of the trigeminal nerve innervate the

Face, scalp, cornea, nasal/oral cavities, dura mater

Motor fibers of the trigeminal nerve innervate the

Masseter, tensor tympani

CN VI

Abducens

Cell bodies of the abducens nerve originate at the

Abducens nucleus

Abducens nerve function

Lateral eye movement

The abducens nerve Innervates the

Lateral rectus msucle

CN VII

Facial