SHANDONG UNIVERSITY Liu Zhiyu
The brain stem SHANDONG UNIVERSITY Liu Zhiyu The brain stem Consistsof Midbrain Pons Medulla oblongata The brain stem Position
The brain stem occupies the posterior cranial fossa of the skull Gross Appearance of the Brain Stem Ventral Surface of the Brain Stem
Medulla oblongata Pyramid: Composed of bundles of nerve fiber, pyramidal tract Decussation of pyramid: Formed by crossing fibers of pyramidal tract Olive: Produced by underlying inferior olivary nucleus Anterolateral sulcus : Emerge the roots of hypoglossal nerve Retroolivary sulcus : Emerge the roots of glossopharyngeal, vagus and accessory nerves Ventral Surface of the Brain Stem
Pons Basilar part Basilar sulcus Bulbopontine sulcus: There emerge, from medial to lateral, the abducent, facial and vestibulocochlear nerves Middle cerebellar peduncle Trigeminal nerve Emerges from the junction of basilar part and middle cerebellar peduncles Pontocerebellar trigone: The junction of medulla, pons and cerebellum Ventral Surface of the Brain Stem
Midbrain Crus cerebri Interpeduncular fossa Oculomotor nerve emerges on the medial side crus cerebri Posterior perforatedsubstance Dorsal Surface of the Brain Stem
Medulla oblongata Lower portion Gracile tubercle: produced by underlying gracile nucleus Cuneate tubercle: produced by underlying cuneate nucleus Inferior cerebellar peduncle Obex Upper portion: forms the lower half of rhomboid fossa Dorsal Surface of the Brain Stem
Pons Superior cerebellar peduncle Superior medullary velum Trochlear nerve Dorsal Surface of the Brain Stem
Midbrain Superior colliculus Constitute centers for visual reflexes Inferior colliculus Associated with auditory pathway Brachium of superior colliculus Brachium of inferior colliculus Fourth ventricle Position
Central canal fourth ventricle mesencephalic aqueductthird ventricle Position Situated ventral to cerebellum, and dorsal to pons and cranial half of medulla Floor of the Fourth ventricle Rhomboid Fossa
Boundaries Inferolateral: gracile and cuneate tubercles, inferior cerebellar peduncle Superolateral: superior cerebellar peduncle Lateral recess Floor of the Fourth ventricle Rhomboid Fossa
Features Median sulcus Sulcus limitans Vestibular area Overlies vestibular nuclei Acoustic tubercle Overlying dorsal cochlear nucleus Medial eminence Striae medullares Floor of the Fourth ventricle Rhomboid Fossa
Facial colliculus Overlies nucleus of abducent n. and genu of facial nerve Hypoglossal triangle Overlies hypoglossal nucleus Vagal triangle Overlies dorsal nucleus of vagus nerve Funiculus separans Area postrema Locus ceruleus Bluish-gray in color, it owes its color to a group of deeply pigmented nerve cells Roof of the Fourth ventricle
Anterior part: Formed by superior cerebellar peduncle and superior medullary velum Posterior part: Formed by inferior medullary velum and choroid plexus of fourth ventricle Three apertures Median aperture of fourth ventricle Two lateral apertures of fourth ventricle Tela choroidea and choroid plexus Internal structure of the brain Stem Internal structure of the brain Stem
Central canal Gray matter Cranial nerve nuclei Relaynuclei White matter Reticular formation of brain stem General somatic motor nuclei Special visceral motor nuclei General visceral motor nuclei Visceral sensory nuclei ( general and special ) General somatic sensory nuclei Special visceral motor nuclei Cranial nerve nuclei General somatic motor nuclei
Nucleus of oculomotor n. Nucleus of trochlear n. Nucleus of abducent n. Nucleus of hypoglossal n. General somatic motor nuclei
Nucleus of oculomotor n. Nucleus of trochlear n. Nucleus of abducent n. Nucleus of hypoglossal n. General somatic motor nuclei
Nucleus Site Cranial n. Function Nucleus of oculomotor n. Midbrain Supreior, inferior,and medial recti,inf. obliquus, levator palpebrae superioris trochlear n. Superior obliquus Nucleus of abducent n. Pons Lateral rectus Nucleus of hypoglossal n. Medulla Muscles of tongue Special visceral motor nuclei
Motor nucleus of trigeminal n. Nucleus of facial n. Nucleus ambiguus Accessory nucleus Special visceral motor nuclei
Motor nucleus of trigeminal n. Nucleus of facial n. Nucleus ambiguus Accessory nucleus Special visceral motor nuclei Medulla-cervical cord
Nucleus Site Cranial n. Function Motor nucleus of trigeminal n. Pons Masticatory muscles, anterior belly of digastric, mylohyoid Nucleus of facial n. Facial m., platysma, posterior belly of digastric, stylohyoid,stapedius Nucleus ambiguus Medulla ,, Skeletal m. of pharynx, larynx and upper part of esophagus Accessory nucleus Medulla-cervical cord Sternocleidomastoid, trapezius General visceral motor nuclei
Accessory oculomotor nucleus Superior salivatory nucleus Inferior salivertory nucleus Dorsal nucleus of vagus n. General visceral motor nuclei
Nucleus Site Cranial n. Function Accessory oculomotor nucleus Midbrain Sphincter pupillae and ciliary m. Superior salivatory nucleus Pons Submandibular, sublingual and lacrimal glands Inferior salivertory nucleus Medulla Parotid gland Dorsal nucleus of vagus n. medulla Many cervical, thoracic and abdominal viscera Visceral sensory nuclei ( general and special )
Nucleus of solitary tract Visceral sensory nuclei ( general and special )
Nucleus Site Cranial n. Function Nucleus of solitary tract Medulla ,, Taste and visceral sensation General somatic sensory nuclei
Mesencephalic nucleus of trigeminal n. Pontine nucleus of trigeminal n. Spinal nucleus of trigeminal n. General somatic sensory nuclei
Nucleus Site Cranial n. Function Mesencephalic nucleus of trigeminal n. Midbrain Proprioception of head Pontine nucleus of trigeminal n. Pons Tactile sensation of head Spinal nucleus of trigeminal n. Medulla Pain and temperature sense of head Special somatic sensory nuclei
Cochlear nuclei Vestibular nuclei Special somatic sensory nuclei
Nucleus Site Cranial n. Function Cochlear nuclei Pons and medulla Sense of hearing Vestibularnuclei Sense of equilibrium Relay nuclei Superior colliculus Nucleus of inferior colliculus
Red nucleus Substantia nigra Pretectal area Superior olivery nucleus Pontine nucleus Nucleus ceruleus Gracile nucleus Cuneate nucleus Inferior olivary nucleus Non-cranial nerve nuclei
Nucleus Site Superior colliculus Midbrain Nucleus of inferior colliculus Red nucleus Substantia nigra Pretectal area Superior olivery nucleus Pons Pontine nucleus pons Nucleus ceruleus Gracile nucleus Medulla (underneath gracile tubercle) Cuneate nucleus Medulla (underneath cuneate tubercle) Inferior olivary nucleus Medulla White matter Ascending tracts Medial lemniscus
Spinothalamic tract Spinal lemniscus Trigeminothalamic tract Trigeminal lemniscus Lateral lemniscus Ascending tracts Medial lemniscus Central thalamic radiation VPL
3neurons Medial lemniscus Gracile and cuneate nuclei 2neuron Decussation of medial lemniscus Fasciculus cuneatus T4 Fasciculus gracilis Spinal ganglion 1neuron Ascending tracts Spinothalamic tract Central thalamic radiation
Spinal lemniscus VPL 3neurons Spinal lemniscus anterior spinothalamic tract Lamina,~ 2neuron Lateral spinothalamic tract Spinalganglia 1neuron Ascending tracts Trigeminothalamic tract Central thalamic radiation
Trigeminal lemniscus VPM 3neurons Pontine nucleus ofV 2neuron Trigeminal lemniscus Trigeminal ganglion 1neuron Spinal tract of trigeminal n. Spinal nucleus ofV 2neuron Ascendingtracts Lateral lemniscus Descending tracts Pyromidal tract Rubrospinal tract Tectospinal tract
Corticospinal tract Corticonuclear tract Rubrospinal tract Tectospinal tract Vestibulospinal tract Reticulospinal tract Reticular Formation of Brain Stem
Ascending reticular activating system (ARAS) Motor central and vital centres Reticulospinal tract Cardiovascular center Respiratory center Serotonergic rapheal nuclei The characters of internal structure of brain stem Medulla oblongata Lower part (closed part) Two decussations
Decussations of medial lemniscus Decussations of pyramid Medulla oblongata Upper part (open part)
Appearance of inferior olivary nuculeus and inferior cerebellar peduncle Enlargement of central canal to form the fourth ventricle floor Pons Tegmentum of pons Basilar part
Directed upward continuation of medulla oblongata Basilar part Contain both longitudinal and transverse fibers intermixed with pontine nuclei Midbrain Rectum of midbrain Cerebral peduncle Tegmentum
Includes superior and inferior colliculi Cerebral peduncle Tegmentum contain ascending tracts, mesencephalic aqueduct, central gray matter, recticular formation and so on Substentia nigra Crus cerebri Pyramidal tract middle three-fifths of the crus Frontopontine tract medial one-fifth Pariatotempopontine tract lateral one-fifth Midbrain Rectum of midbrain Cerebral peduncle Tegmentum
Includes superior and inferior colliculi Cerebral peduncle Tegmentum contain ascending tracts, mesencephalic aqueduct, central gray matter, red nucleus, recticular formation and so on Substentia nigra Crus cerebri Pyramidal tract middle three-fifths of the crus Frontopontine tract medial one-fifth Pariatotempopontine tract lateral one-fifth