瞳孔散大筋
- 関
- musculus dilator pupillae
WordNet
- a surgical instrument that is used to dilate or distend an opening or an organ (同)dilater
- a drug that causes dilation
- a muscle or nerve that dilates or widens a body part
- of or relating to the pupil of the eye
Wikipedia preview
出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/12/31 13:13:36」(JST)
[Wiki en表示]
| Iris dilator muscle |
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| Iris, front view. (Muscle visible but not labeled.) |
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| The upper half of a sagittal section through the front of the eyeball. (Iris dilator muscle is NOT labeled and not to be confused with "Radiating fibers" labeled near center, which are part of the ciliary muscle.) |
| Latin |
musculus dilatator pupillae |
| Gray's |
subject #225 1013 |
| Origin |
outer margins of iris[1] |
| Insertion |
inner margins of iris[1] |
| Artery |
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| Nerve |
Long ciliary nerves (sympathetics) |
| Actions |
dilates pupil |
| Antagonist |
iris sphincter muscle |
The iris dilator muscle (pupil dilator muscle, pupillary dilator, radial muscle of iris, radiating fibers), is a smooth muscle[2] of the eye, running radially in the iris and therefore fit as a dilator. The pupillary dilator consists of a spokelike arrangement of modified contractile cells called myoepithelial cells. These cells are stimulated by the sympathetic nervous system[3]. In fact, the innervation of these cells comes from the parasympathetic component of cranial nerve III (Oculomotor Nerve)[4] . When stimulated by the sympathetic nervous system, the cells contract, widening the pupil and allowing for more light to pass through the eye. Pupillary dilation occurs in two situations: when light intensity changes and when we shift our gaze between distant and nearby objects[3]. The pupillary dilator acts as an antagonist to the pupillary constrictor which narrows the pupil and admits less light to the eye. It has its origin from the anterior epithelium.[5] It is innervated by the sympathetic system, which acts by releasing noradrenaline, which acts on α1-receptors.[6] Thus, when presented with a threatening stimuli that activates the fight-or-flight response, this innervation contracts the muscle and dilates the iris, thus temporarily letting more light reach the retina. The pupillary dilator acts as an antagonist to the pupillary constrictor which narrows the pupil and admits less light to the eye.
The dilator muscle is innervated more specifically by postganglionic sympathetic nerves arising from the superior cervical ganglion as the Sympathetic root of ciliary ganglion. They will follow both short ciliary and long ciliary nerves to reach the dilator muscle.
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Contents
- 1 Additional images
- 2 See also
- 3 References
- 4 External links
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Additional images
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Scheme showing sympathetic and parasympathetic innervation of the pupil and sites of lesion in a Horner's syndrome.
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Sympathetic connections of the ciliary and superior cervical ganglia.
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The iris dilator muscle fibers course radially through the iris.
See also
- Iris sphincter muscle
- Mydriasis
References
- ^ a b Gest, Thomas R; Burkel, William E. "Anatomy Tables - Eye." Medical Gross Anatomy. 2000. University of Michigan Medical School. 5 Jan. 2010 <http://anatomy.med.umich.edu/nervous_system/eye_tables.html>.
- ^ jneurosci.org Muscarinic and Nicotinic Synaptic Activation of the Developing..
- ^ a b Saladin, Kenneth (2012). Anatomy and Physiology. McGraw-Hill. pp. 616-617.
- ^ Swenson, Rand. "Eye Movements". Disorders of the Nervous System. http://www.dartmouth.edu/~dons/part_1/chapter_4.html.
- ^ "eye, human." Encyclopædia Britannica. Encyclopaedia Britannica Ultimate Reference Suite. Chicago: Encyclopædia Britannica, 2010.
- ^ Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4. Page 163
External links
- Description of function at tedmontgomery.com
- Slide at mscd.edu
- dilator+pupillae+muscle at eMedicine Dictionary
- BU Histology Learning System: 08010loa
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Sensory system – visual system – globe of eye (TA A15.2.1–6, TH 3.11.08.0-5, GA 10.1005)
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| Fibrous tunic (outer) |
| Sclera |
- Episcleral layer
- Schlemm's canal
- Trabecular meshwork
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| Cornea |
- Limbus
- layers
- Epithelium
- Bowman's
- Stroma
- Descemet's
- Endothelium
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| Uvea/vascular tunic (middle) |
| Choroid |
- Capillary lamina of choroid
- Bruch's membrane
- Sattler's layer
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| Ciliary body |
- Ciliary processes
- Ciliary muscle
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| Iris |
- Stroma
- Pupil
- Iris dilator muscle
- Iris sphincter muscle
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| Retina (inner) |
| Layers |
- Inner limiting membrane
- Nerve fiber layer
- Ganglion cell layer
- Inner plexiform layer
- Inner nuclear layer
- Outer plexiform layer
- Outer nuclear layer
- External limiting membrane
- Layer of rods and cones
- Retinal pigment epithelium
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| Cells |
Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell (Midget cell, Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K cell
Muller glia
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| Other |
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| Anterior segment |
- Anterior chamber
- Aqueous humour
- Posterior chamber
- Lens
- Capsule of lens
- Zonule of Zinn
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| Posterior segment |
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| Other |
- Ocular immune system
- Tapetum lucidum
- Keratocytes
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anat (g/a/p)/phys/devp/prot
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proc, drug (S1A/1E/1F/1L)
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Sensory system: Visual system and eye movement pathways
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| Visual perception |
1° (Bipolar cell of Retina) → 2° (Ganglionic cell) → 3° (Optic nerve → Optic chiasm → Optic tract → LGN of Thalamus) → 4° (Optic radiation → Cuneus and Lingual gyrus of Visual cortex → Blobs → Globs)
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| Muscles of orbit |
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Tracking
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Smooth pursuit: Parietal lobe · Occipital lobe
Saccade: Frontal eye fields
Nystagmus → Fixation reflex → PPRF |
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Horizontal gaze
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PPRF → Abducens nucleus → MLF → Oculomotor nucleus → Medial rectus muscle
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Vertical gaze
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Rostral interstitial nucleus → Oculomotor nucleus, Trochlear nucleus → Muscles of orbit
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Vestibulo-ocular reflex
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Semicircular canal → Vestibulocochlear nerve → Vestibular nuclei → Abducens nucleus → MLF (Vestibulo-oculomotor fibers) → Oculomotor nucleus → Medial rectus muscle
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| Pupillary reflex |
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Pupillary dilation
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1° (Posterior hypothalamus → Ciliospinal center) → 2° (Superior cervical ganglion) → 3° (Sympathetic root of ciliary ganglion → Nasociliary nerve → Long ciliary nerves → Iris dilator muscle)
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Pupillary light reflex
(constriction)
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1° (Retina → Optic nerve → Optic chiasm → Optic tract → Pretectal nucleus) → 2° (Edinger-Westphal nucleus) → 3° (Oculomotor nerve → Parasympathetic root of ciliary ganglion → Ciliary ganglion) → (4° Short ciliary nerves → Iris sphincter muscle)
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Accommodation
vergence
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1° (Retina → Optic nerve → Optic chiasm → Optic tract → Visual cortex → Brodmann area 19 → Pretectal area) → 2° (Edinger-Westphal nucleus) → 3° (Short ciliary nerves → Ciliary ganglion → Ciliary muscle)
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| Circadian rhythm |
Retina → Hypothalamus (Suprachiasmatic nucleus)
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anat (g/a/p)/phys/devp/prot
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proc, drug (S1A/1E/1F/1L)
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UpToDate Contents
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English Journal
- Ultrabiomicroscopic-histopathologic correlations in individuals with autosomal dominant congenital microcoria: three-generation family report.
- Ramirez-Miranda A, Paulin-Huerta JM, Chavez-Mondragon E, Islas-de la Vega G, Rodriguez-Reyes A.SourceAnterior Segment Department, Instituto de Oftalmologia Fundacion Conde de Valenciana, Mexico City, Mexico.
- Case reports in ophthalmology.Case Report Ophthalmol.2011 May;2(2):160-5. Epub 2011 May 13.
- BACKGROUND: Congenital microcoria (CMC) is due to a maldevelopment of the dilator pupillae muscle of the iris, with a pupil diameter of less than 2 mm. It is associated with juvenile open angle glaucoma and myopia. We report on a three-generation Mexican-Mestizo family with CMC. The eldest member's
- PMID 21677884
- Intraoperative phacoemulsification complication rates of second- and third-year ophthalmology residents a 5-year comparison.
- Woodfield AS, Gower EW, Cassard SD, Ramanthan S.SourceThe Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. alonzo.woodfield@gmail.com
- Ophthalmology.Ophthalmology.2011 May;118(5):954-8.
- OBJECTIVE: To determine whether year of residency is associated with intraoperative phacoemulsification complication rates.DESIGN: Retrospective cohort study.PARTICIPANTS: One attending physician supervised 691 resident-performed phacoemulsification procedures on 492 patients. Second- and third-year
- PMID 21539981
Japanese Journal
- 筋の生理学的特性を考慮した瞳孔光反射系モデルの構築
- 堺 浩之,山地 一禎,臼井 支朗
- 電子情報通信学会技術研究報告. MBE, MEとバイオサイバネティックス 98(672), 93-100, 1999-03-19
- 瞳孔光反射系は, 網膜に投射される光量を調節するといった明確な機能を持つ, 生体における不随意な制御系の典型例である. 本研究では, そうした瞳孔光反射系のうち, 特に生理学的な知見が豊富に存在する瞳孔筋系の特性に着目した数理モデルを構築した. 構築したモデルは, 光刺激に対して神経信号を生成する網膜・中枢神経系と, その信号に駆動される筋系の2つのサブシステムからなる. 瞳孔筋系は, 粘弾性モデ …
- NAID 110003287572
- 山地 一禎,平田 豊,臼井 支朗,長岡 俊治
- 電子情報通信学会技術研究報告. MBE, MEとバイオサイバネティックス 95(404), 1-6, 1995-12-09
- 瞳孔は自律神経系の支配下にあり外部から容易に観測可能なことから,近年,非侵襲的な自律神経系活動モニタとして注目されている.本研究では,まず,これまでに構築した瞳孔筋系モデルを用いた解析から,従来経験的にしか知られていない,自律神経系活動と瞳孔フラッシュ応答の特徴パラメータの関係を明らかにした.さらに,瞳孔筋系に内在するrange nonlinearity特性についても考察を加えることにより,瞳孔フ …
- NAID 110003287096
Related Links
- The iris dilator muscle (pupil dilator muscle, pupillary dilator, radial muscle of iris, radiating fibers), is a smooth muscle of the eye, running radially in the iris and therefore fit as a dilator. It has its origin from the anterior ...
Related Pictures
★リンクテーブル★
[★]
瞳孔散大筋
- 関
- pupillary dilator
[★]
[★]
- 関
- pupil