出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2018/03/26 17:24:59」(JST)
脳: 橋 | |
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大脳
間脳
中脳
橋
延髄
脊髄
小脳
脳の矢状断。茶色が橋。
脳内での橋の位置。橋を赤で示す。左図は側面から、右図は正面から見たとき(画像出典:Anatomography)
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名称 | |
日本語 | 橋 |
英語 | Pons |
関連構造 | |
上位構造 | 脳幹 |
構成要素 | 第四脳室 |
動脈 | 橋動脈 |
静脈 | 横橋静脈、外側橋静脈 |
画像 | |
アナトモグラフィー | 三次元CG |
Digital Anatomist | 左側面 内側 |
関連情報 | |
IBVD | 体積(面積) |
Brede Database | 階層関係、座標情報 |
NeuroNames | 関連情報一覧 |
NIF | 総合検索 |
MeSH | Pons |
グレイの解剖学 | 書籍中の説明(英語) |
テンプレートを表示 |
橋(きょう、羅: 英: pons)は、脳の部位の一つ。脳幹に含まれ、前後を中脳と延髄とに挟まれる。第四脳室の腹側壁をなす。第四脳室をはさんで背側には小脳がある。
前腹側から脳幹の外観を観察すると、小脳の腹側からのびた強大な線維束(中小脳脚)が、脳幹の一部を乗り越え、これをつつむように盛り上がってみえることから、この部位を小脳からでた「橋」にみたてて、この名がついた。
延髄の上方に続く部分で、腹方の著しく膨出した橋底部と、延髄の直接の続きである背方の橋背部(被蓋)とからなる。橋底部には橋核という巨大な灰白質があり、その内部を錐体路と皮質橋核路が貫いて走る。橋核の神経細胞は大脳皮質からきた皮質橋核路の線維を受け、反対側の小脳半球へ大量の線維(中小脳脚)を送るすなわち、小脳は橋核を介して大脳皮質の支配を受けている。
三叉神経、外転神経、顔面神経、聴神経といった多くの脳神経核が存在する。脳神経が出る部位である。脳幹を経由する多くの伝導路が通過する他、大脳皮質からの運動性出力を橋核、中小脳脚を経由して、小脳へと伝える経路などが存在する。
橋の形を様々な方向から見た動画。橋を赤で、中脳と延髄を茶色で、それ以外の所を半透明にして示してある。(画像出典:Anatomography)
橋の下部の横断面の模式図。外転神経核や顔面神経核、前庭神経核などを含む
ウィキメディア・コモンズには、橋 (脳)に関連するカテゴリがあります。 |
この項目は、医学に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めています(プロジェクト:医学/Portal:医学と医療)。 |
Pons | |
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Pons in the brainstem
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Anteroinferior view of the medulla oblongata and pons
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Details | |
Part of | Brain stem |
Artery | pontine arteries |
Vein | transverse and lateral pontine veins |
Identifiers | |
MeSH | D011149 |
NeuroNames | 547 |
NeuroLex ID | birnlex_733 |
TA | A14.1.03.010 |
FMA | 67943 |
Anatomical terms of neuroanatomy
[edit on Wikidata]
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The pons is part of the brainstem, and in humans and other bipeds lies inferior to the midbrain, superior to the medulla oblongata and anterior to the cerebellum.
The pons is also called the pons Varolii ("bridge of Varolius"), after the Italian anatomist and surgeon Costanzo Varolio (1543–75).[1] This region of the brainstem includes neural pathways and tracts that conduct signals from the brain down to the cerebellum and medulla, and tracts that carry the sensory signals up into the thalamus.[2]
The pons in humans measures about 2.5 centimetres (0.98 in) in length. Most of it appears as a broad anterior bulge rostral to the medulla. Posteriorly, it consists mainly of two pairs of thick stalks called cerebellar peduncles. They connect the cerebellum to the pons and midbrain.[2]
The pons contains nuclei that relay signals from the forebrain to the cerebellum, along with nuclei that deal primarily with sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture.[2]
Within the pons is the pneumotaxic center consisting of the subparabrachial and the medial parabrachial nuclei. This center regulates the change from inhalation to exhalation.[2]
The pons is implicated in sleep paralysis, and may also play a role in generating dreams.[citation needed]
The pons is in the brainstem situated between the midbrain and the medulla oblongata, and in front of the cerebellum. The pons can be broadly divided into two parts: the basilar part of the pons (ventral pons), and the pontine tegmentum (dorsal pons).
During embryonic development, the metencephalon develops from the rhombencephalon and gives rise to two structures: the pons and the cerebellum.[2] The alar plate produces sensory neuroblasts, which will give rise to the solitary nucleus and its special visceral afferent (SVA) column; the cochlear and vestibular nuclei, which form the special somatic afferent (SSA) fibers of the vestibulocochlear nerve, the spinal and principal trigeminal nerve nuclei, which form the general somatic afferent column (GSA) of the trigeminal nerve, and the pontine nuclei which relays to the cerebellum.
Basal plate neuroblasts give rise to the abducens nucleus, which forms the general somatic efferent fibers (GSE); the facial and motor trigeminal nuclei, which form the special visceral efferent (SVE) column, and the superior salivatory nucleus, which forms the general visceral efferent fibers of the facial nerve.
A number of cranial nerve nuclei are present in the pons:
The functions of these four cranial nerves (V-VIII) include sensory roles in hearing, equilibrium, and taste, and in facial sensations such as touch and pain, as well as motor roles in eye movement, facial expressions, chewing, swallowing, and the secretion of saliva and tears.[3]
The pons first evolved as an offshoot of the medullary reticular formation.[4] Since lampreys possess a pons, it has been argued that it must have evolved as a region distinct from the medulla by the time the first agnathans appeared, 505 million years ago.[5]
Location and topography of Pons (animation)
Axial section of the pons, at its upper part
Hind- and mid-brains; posterolateral view
Median sagittal section of brain
Nuclei of the pons and brainstem
Cerebrum. Deep dissection. Inferior dissection.
arjun korah.2007
was invoked but never defined (see the help page).Saladin Kenneth S.(2007) Anatomy & physiology the unity of form and function. Dubuque, IA: McGraw-Hill
Wikimedia Commons has media related to Pons. |
Nervous system
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Central nervous system |
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Peripheral nervous system |
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Anatomy of the pons
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Dorsal/ (tegmentum) |
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Ventral/ (base) |
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Other grey: Raphe/ reticular |
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関連記事 | 「Po」 |
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