The brain stem 脑干 山东大学医学院 解剖教研室 李振华

学习方法 看外形，想内部，内外结合。 看断面，想立体，上下串联。 记重点，莫贪多，整理表格。

The brain stem 脑干 Consists of Midbrain 中脑 Pons 脑桥 Medulla oblongata 延髓

The brain stem 脑干 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 锥体: Composed of bundles of nerve fiber, pyramidal tract 锥体束 Decussation of pyramid 锥体交叉: Formed by crossing fibers of pyramidal tract Olive 橄榄: Produced by underlying inferior olivary nucleus 下橄榄核 Anterolateral sulcus 前外侧沟: Emerge the roots of hypoglossal nerve Retroolivary sulcus 橄榄后沟: Emerge the roots of glossopharyngeal, vagus and accessory nerves

Ventral Surface of the Brain Stem Pons Basilar part 基底部 Basilar sulcus 基底沟 Bulbopontine sulcus 延髓脑桥沟: There emerge, from medial to lateral, the abducent, facial and vestibulocochlear nerves Middle cerebellar peduncle 小脑中脚 Trigeminal nerve 三叉神经 Emerges from the junction of basilar part and middle cerebellar peduncles Pontocerebellar trigone 脑桥小脑三角: The junction of medulla, pons and cerebellum

Ventral Surface of the Brain Stem Midbrain Crus cerebri 大脑脚底 Interpeduncular fossa 脚间窝 Oculomotor nerve emerges on the medial side crus cerebri Posterior perforated substance 后穿质

Dorsal Surface of the Brain Stem Medulla oblongata Lower portion Gracile tubercle 薄束结节: produced by underlying gracile nucleus 薄束核 Cuneate tubercle 楔束结节: produced by underlying cuneate nucleus 楔束核 Inferior cerebellar peduncle 小脑下脚 Obex 闩 Upper portion: forms the lower half of rhomboid fossa

Dorsal Surface of the Brain Stem Pons Superior cerebellar peduncle 小脑上脚 Superior medullary velum 上髓帆 Trochlear nerve 滑车神经

Dorsal Surface of the Brain Stem Midbrain Superior colliculus 上丘 Constitute centers for visual reflexes Inferior colliculus 下丘 Associated with auditory pathway Brachium of superior colliculus 上丘臂 Brachium of inferior colliculus 下丘臂

Fourth ventricle 第四脑室 Position Central canal →fourth ventricle →mesencephalic aqueduct→third ventricle Position Situated ventral to cerebellum, and dorsal to pons and cranial half of medulla

Floor of the Fourth ventricle — Rhomboid Fossa 菱形窝 Boundaries Inferolateral: gracile and cuneate tubercles, inferior cerebellar peduncle Superolateral: superior cerebellar peduncle Lateral recess

Floor of the Fourth ventricle — Rhomboid Fossa 菱形窝 Features Median sulcus 正中沟 Sulcus limitans 界沟 Vestibular area 前庭区　 　　 Overlies vestibular nuclei Acoustic tubercle 听结节 Overlying dorsal cochlear nucleus Medial eminence 内侧隆起 Striae medullares 髓纹

Floor of the Fourth ventricle — Rhomboid Fossa 菱形窝 Facial colliculus 面神经丘 Overlies nucleus of abducent n. and genu of facial nerve Hypoglossal triangle 舌下神经三角 Overlies hypoglossal nucleus Vagal triangle 迷走神经三角 Overlies dorsal nucleus of vagus nerve Funiculus separans 分隔索 Area postrema 最后区 Locus ceruleus 蓝斑 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小脑上脚 and superior medullary velum 上髓帆 Posterior part: Formed by inferior medullary velum 下髓帆 and choroid plexus of fourth ventricle 第四脑室脉络丛 Three apertures Median aperture of fourth ventricle 第四脑室正中孔 Two lateral apertures of fourth ventricle 第四脑室外侧孔

Tela choroidea and choroid plexus 脉络丛和脉络组织

Internal structure of the brain Stem

Internal structure of the brain Stem Central canal Gray matter Cranial nerve nuclei 脑神经核 Relay nuclei 传导中继核 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 一般躯体运动核 Nucleus of oculomotor n.动眼神经核 Nucleus of trochlear n. 滑车神经核 Nucleus of abducent n. 展神经核 Nucleus of hypoglossal n.舌下神经核

General somatic motor nuclei 一般躯体运动核 Nucleus of oculomotor n.动眼神经核 Nucleus of trochlear n. 滑车神经核 Nucleus of abducent n. 展神经核 Nucleus of hypoglossal n.舌下神经核

General somatic motor nuclei Nucleus Site Cranial n. Function Nucleus of oculomotor n. Midbrain Ⅲ Supreior, inferior,and medial recti, inf. obliquus, levator palpebrae superioris trochlear n. Ⅳ Superior obliquus Nucleus of abducent n. Pons Ⅵ Lateral rectus Nucleus of hypoglossal n. Medulla Ⅻ Muscles of tongue

Special visceral motor nuclei 特殊内脏运动核 Motor nucleus of trigeminal n. 三叉神经运动核 Nucleus of facial n. 面神经核 Nucleus ambiguus 疑核 Accessory nucleus 副神经核

Special visceral motor nuclei 特殊内脏运动核 Motor nucleus of trigeminal n. 三叉神经运动核 Nucleus of facial n. 面神经核 Nucleus ambiguus 疑核 Accessory nucleus 副神经核

Special visceral motor nuclei Medulla-cervical cord Nucleus Site Cranial n. Function Motor nucleus of trigeminal n. Pons Ⅴ Masticatory muscles, anterior belly of digastric, mylohyoid Nucleus of facial n. Ⅶ Facial m., platysma, posterior belly of digastric, stylohyoid, stapedius Nucleus ambiguus Medulla Ⅸ,Ⅹ, Ⅺ Skeletal m. of pharynx, larynx and upper part of esophagus Accessory nucleus Medulla-cervical cord Ⅺ Sternocleidomastoid, trapezius

General visceral motor nuclei 一般内脏运动核 Accessory oculomotor nucleus 动眼神经副核 Superior salivatory nucleus 上泌涎核 Inferior salivertory nucleus 下泌涎核 Dorsal nucleus of vagus n. 迷走神经背核

General visceral motor nuclei Nucleus Site Cranial n. Function Accessory oculomotor nucleus Midbrain Ⅲ Sphincter pupillae and ciliary m. Superior salivatory nucleus Pons Ⅶ Submandibular, sublingual and lacrimal glands Inferior salivertory nucleus Medulla Ⅸ Parotid gland Dorsal nucleus of vagus n. medulla Ⅹ Many cervical, thoracic and abdominal viscera

Visceral sensory nuclei ( general and special ) Nucleus of solitary tract 孤束核

Visceral sensory nuclei ( general and special ) Nucleus Site Cranial n. Function Nucleus of solitary tract Medulla Ⅶ,Ⅸ,Ⅹ Taste and visceral sensation

General somatic sensory nuclei 一般躯体感觉核 Mesencephalic nucleus of trigeminal n. 三叉神经中脑核 Pontine nucleus of trigeminal n. 三叉神经脑桥核 Spinal nucleus of trigeminal n. 三叉神经脊束核

General somatic sensory nuclei Nucleus Site Cranial n. Function Mesencephalic nucleus of trigeminal n. Midbrain Ⅴ 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 特殊躯体感觉核 Cochlear nuclei 蜗神经核 Vestibular nuclei 前庭神经核

Special somatic sensory nuclei Nucleus Site Cranial n. Function Cochlear nuclei Pons and medulla Ⅷ Sense of hearing Vestibular nuclei Sense of equilibrium

Relay nuclei 中继核 Superior colliculus 上丘 Nucleus of inferior colliculus下丘核 Red nucleus 红核 Substantia nigra 黑质 Pretectal area 顶盖前区 Superior olivery nucleus 上橄榄核 Pontine nucleus 脑桥核 Nucleus ceruleus 蓝斑核 Gracile nucleus 薄束核 Cuneate nucleus 楔束核 Inferior olivary nucleus 下橄榄核

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 内侧丘系 Spinothalamic tract 脊髓丘脑束 （Spinal lemniscus 脊髓丘系） Trigeminothalamic tract 三叉丘脑束 （Trigeminal lemniscus 三叉丘系） Lateral lemniscus 外侧丘系

Ascending tracts Medial lemniscus Central thalamic radiation VPL 内侧丘系 VPL 3°neurons Medial lemniscus Gracile and cuneate nuclei 2°neuron Decussation of medial lemniscus Fasciculus cuneatus T4 Fasciculus gracilis Spinal ganglion 1°neuron

Ascending tracts Spinothalamic tract Central thalamic radiation 脊髓丘脑束 （Spinal lemniscus脊髓丘系） VPL 3°neurons Spinal lemniscus anterior spinothalamic tract LaminaⅠ,Ⅳ~Ⅶ 2°neuron Lateral spinothalamic tract Spinal ganglia 1°neuron

Ascending tracts Trigeminothalamic tract Central thalamic radiation 三叉丘脑束 （Trigeminal lemniscus三叉丘系） VPM 3°neurons Pontine nucleus of V 2°neuron Trigeminal lemniscus Trigeminal ganglion 1°neuron Spinal tract of trigeminal n. Spinal nucleus of V 2°neuron

Ascending tracts Lateral lemniscus 外侧丘系

Descending tracts Pyromidal tract 锥体束 Rubrospinal tract 红核脊髓束 Corticospinal tract 皮质脊髓束 Corticonuclear tract 皮质核束 Rubrospinal tract 红核脊髓束 Tectospinal tract 顶盖脊髓束 Vestibulospinal tract 前庭脊髓束 Reticulospinal tract 网状脊髓束

Reticular Formation of Brain Stem Ascending reticular activating system (ARAS) 上行网状激动系统 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 脑桥被盖 Basilar part 基底部 Directed upward continuation of medulla oblongata Basilar part 基底部 Contain both longitudinal and transverse fibers intermixed with pontine nuclei

Midbrain Rectum of midbrain 中脑顶盖 Cerebral peduncle 大脑脚 Tegmentum 被盖 Includes superior and inferior colliculi Cerebral peduncle 大脑脚 Tegmentum 被盖 contain ascending tracts, mesencephalic aqueduct, central gray matter, recticular formation and so on Substentia nigra 黑质 Crus cerebri 大脑脚底 Pyramidal tract 锥体束 middle three-fifths of the crus Frontopontine tract 额桥束 medial one-fifth Pariatotempopontine tract 顶颞桥束 lateral one-fifth

Midbrain Rectum of midbrain 中脑顶盖 Cerebral peduncle 大脑脚 Tegmentum 被盖 Includes superior and inferior colliculi Cerebral peduncle 大脑脚 Tegmentum 被盖 contain ascending tracts, mesencephalic aqueduct, central gray matter, red nucleus, recticular formation and so on Substentia nigra 黑质 Crus cerebri 大脑脚底 Pyramidal tract 锥体束 middle three-fifths of the crus Frontopontine tract 额桥束 medial one-fifth Pariatotempopontine tract 顶颞桥束lateral one-fifth