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Encyclopedia > Sphincter pupillae
Iris sphincter
Iris, front view. (Muscle visible but not labeled.)
The upper half of a sagittal section through the front of the eyeball. ("Circular fibers" labeled near center.)
Latin m. sphincter pupillae
Gray's subject #225 1013
Origin:
Insertion:
Blood:
Nerve: short ciliary nerves
Action: constricts pupil
Antagonist: iris dilator muscle
MeSH [1]
Dorlands/Elsevier m_22/12550831

The iris sphincter muscle (pupillary sphincter, circular muscle of iris, circular fibers) is a muscle in the part of the eye called the iris. The human iris The iris is the green/grey/brown area. ... Wikipedia does not yet have an article with this exact name. ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ... A typical adult human skeleton consists of the following 206 bones, though a small portion of the human population have an extra bone, occurring in the form of an extra rib. ... A typical adult human skeleton consists of the following 206 bones, though a small portion of the human population have an extra bone, occurring in the form of an extra rib. ... List of human nerves External links List of nerves This is an incomplete list, which may never be able to satisfy certain standards for completeness. ... An antagonist is a kind of muscle that act in opposition to the movement generated by the agonists and are responsible for returning a limb to its initial position. ... The Iris dilator muscle is a muscle of the human body. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Elseviers logo Elsevier, the worlds largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. ... The human iris The iris is the green/grey/brown area. ... A top-down view of skeletal muscle Muscle is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... Closeup of a blue-green human eye. ... The human iris The iris is the green/grey/brown area. ...


It is found in vertebrates and some cephalopods. Classes and Clades Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ... Orders Subclass Nautiloidea †Plectronocerida †Ellesmerocerida †Actinocerida †Pseudorthocerida †Endocerida †Tarphycerida †Oncocerida †Discosorida Nautilida †Orthocerida †Ascocerida †Bactritida Subclass †Ammonoidea †Goniatitida †Ceratitida †Ammonitida Subclass Coleoidea †Belemnoidea †Aulacocerida †Belemnitida †Hematitida †Phragmoteuthida Neocoleoidea (most living cephalopods) Sepiida Sepiolida Spirulida Teuthida Octopoda Vampyromorphida The cephalopods (head-foot) are the mollusk class Cephalopoda characterized by bilateral body...


In humans, it functions to constrict the pupil in bright light (pupillary reflex) or during accommodation. The human eye The pupil is the central transparent area (showing as black). ... In medicine, pupil constriction (also known as the pupillary reflex) is reduction of pupil size. ... Human eye The Accommodation Reflex is a reflex action of the eye, in response to focusing on a near object, then looking at distant object (and vice versa). ...


It is controlled by parasympathetic fibers that originate from the Edinger-Westphal nucleus, travel along the oculomotor nerve (CN III), synapse in the ciliary ganglion, and then enter the eye via the short ciliary nerves It has been suggested that Parasympatholytic be merged into this article or section. ... The Edinger-Westphal nucleus is the accessory parasympathetic nucleus of the oculomotor nerve, supplying the constricting muscles of the iris. ... The oculomotor nerve () is the third of twelve paired cranial nerves. ... The ciliary ganglion is small parasympathetic ganglion lying in the orbit between the optic nerve and the lateral rectus muscle that is associated with the nasociliary nerve (a branch of the ophthalmic division of the trigeminal nerve). ...


See also

Miosis should not be confused with meiosis, the cellular division process involved in sexual reproduction. ...

External links

Muscles of the Head — Neck — Trunk — Upper limb — Lower limb— LIST OF ALL MUSCLES

scalp: occipitofrontalis (occipitalis, frontalis) | (Gray's s105) A top-down view of skeletal muscle Muscle is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... This is a list of muscles of the human anatomy. ... The scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly. ... The Occipitofrontalis is a term used by some to describe a muscle of the human body, with two parts: the occipital part/belly, and the frontal part/belly. ... The Occipitalis muscle is a muscle of the human body. ... The Frontalis is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


eyelid: orbicularis oculi - corrugator supercilii - depressor supercilii | (Gray's s106) An eyelid is a thin fold of skin and muscle that covers and protects an eye. ... The Orbicularis oculi is a muscle of the human body. ... Left obicularis oculi notice the corrugator muscle at the top The Corrugator supercilii is a small, narrow, pyramidal muscle, placed at the medial end of the eyebrow, beneath the Frontalis and Orbicularis oculi. ... The Depressor supercilii is an eye muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


nose: procerus - nasalis - depressor septi nasi - dilatator naris posterior - dilatator naris anterior - levator labii superioris alaeque nasi | (Gray's s107) Human nose in profile You may be looking for Nose, a town in Japan, or The Nose, a story by Nikolai Gogol and an opera by Dmitri Shostakovich. ... Procerus muscle Origin/Proximal Attatchment: From fascia over the lower of the nasal bone Insertion/Distal Attatchment: Into the skin of the lower part of the forehead between the eyebrows Action/Relevance: Draws down the medial angle of the eyebrow giving expressions of frowning Innervation: Buccal branch of the facial... The Nasalis (Compressor naris) is a sphincter-like muscle of the nose whose function is to compress the nasal cartilege. ... The Depressor septi nasi is a muscle of the human body, in the nose. ... The Dilatator naris posterior is placed partly beneath the Quadratus labii superioris. ... The Dilatator naris anterior is a delicate fasciculus, passing from the greater alar cartilage to the integument near the margin of the nostril; it is situated in front of the Dilatator naris posterior muscle. ... The levator labii superioris alaeque nasi muscle is, translated from Latin, the lifter of the upper lip and of the wing of the nose. It is the muscle with the longest name in the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


mouth: levator labii superioris - levator anguli oris - zygomaticus (major, minor) - mentalis - depressor labii inferioris - depressor anguli oris - buccinator - orbicularis oris - risorius | (Gray's s108) Sagittal section of nose mouth, pharynx, and larynx. ... The Levator labii superioris is a muscle of the human body used in facial expression. ... The Levator anguli oris is a muscle of the human body. ... The Zygomatic major is a muscle of the human body. ... The Zygomaticus minor is a muscle of the human body. ... The Mentalis is a muscle of the human body. ... The Depressor labii is part of a small quadrilateral muscle. ... The Depressor anguli oris is a muscle of the human body. ... The Buccinator is a thin quadrilateral muscle, occupying the interval between the maxilla and the mandible at the side of the face. ... The orbicularis oris is the sphincter muscle around the mouth. ... The Risorius is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


mastication: masseter - temporalis - pterygoid (lateral, medial) | (Gray's s109) Mastication or chewing is the process by which food is torn and/or crushed by teeth. ... In human anatomy, the masseter is one of the muscles of mastication. ... The temporalis muscle is one of the muscles of mastication. ... The lateral pterygoid is a muscle of mastication with two heads. ... The medial pterygoid is a muscle of mastication with two heads. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


extraocular: levator palpebrae superioris - rectus (superior, inferior, medial, lateral) - oblique (superior, inferior) | intraocular: ciliary - iris dilator - iris sphincter | (Gray's s227) The extraocular muscles are the six muscles that control the movements of the eye. ... The levator palpebrae superioris muscle is a muscle in the orbit that elevates the superior (upper) eyelid. ... The superior rectus muscle is a muscle in the orbit that elevates, adducts, and rotates the eye medially. ... The inferior rectus muscle is a muscle in the orbit that depresses, adducts, and rotates the eye laterally. ... The medial rectus muscle is a muscle in the orbit that adducts the eyeball (makes it move inwards). ... The lateral rectus muscle is a muscle in the orbit that abducts the eyeball (makes it move outwards). ... The superior oblique muscle is a muscle in the orbit that causes the eye to look downwards when it is already directed medially (looking towards the nose). ... The inferior oblique muscle is a muscle in the orbit that adducts (medially rotates) and elevates the eyeball. ... Closeup of a blue-green human eye. ... Grays FIG. 872- The choroid and iris. ... The Iris dilator muscle is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


hearing: auricularis anterior - stapedius - tensor tympani | (Gray's s228-Gray's s232) Hearing, or audition, is one of the traditional five senses, and refers to the ability to detect sound. ... The muscles of the auricula. ... The stapedius is the smallest striated muscle in the human body. ... The tensor tympani muscle arises from the auditory tube and inserts onto the handle of the malleus, damping down vibration in the ossicles and so reducing the amplitude of sounds. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


larynx: cricothyroid - posterior cricoarytenoid - lateral cricoarytenoid - arytenoid - thyroarytenoid | (Gray's s236) The pharynx (plural pharynx), or voicebox, is an organ in the neck of mammals involved in protection of the trachea and sound production. ... The cricothyroid muscle attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage, tilting the thyroid forwards and lengthening the vocal cords. ... The posterior cricoarytenoid muscles allow the rima glottidis to be opened; they therefore have the opposite effect to the lateral cricoarytenoid muscles. ... The lateral cricoarytenoid muscles allow the rima glottidis to be closed, protecting the airway; they therefore have the opposite effect to the posterior cricoarytenoid muscles. ... The Arytænoideus is a single muscle, filling up the posterior concave surfaces of the arytenoid cartilages. ... The Thyreoarytænoideus (Thyroarytenoid) is a broad, thin, muscle which lies parallel with and lateral to the vocal fold, and supports the wall of the ventricle and its appendix. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


tongue: extrinsic (genioglossus - hyoglossus - chondroglossus - styloglossus) intrinsic (superior longitudinal - inferior longitudinal - transversus - verticalis) | (Gray's s242) Tongue The tongue is the large bundle of muscles on the floor of the mouth that manipulates food for chewing and swallowing. ... The Genioglossus is a muscle of the human body. ... The Hyoglossus is a muscle of the human body. ... The Chondroglossus is sometimes described as a part of the Hyoglossus, but is separated from it by fibers of the Genioglossus, which pass to the side of the pharynx. ... The Styloglossus, the shortest and smallest of the three styloid muscles, arises from the anterior and lateral surfaces of the styloid process, near its apex, and from the stylomandibular ligament. ... The Superior longitudinal muscle is a muscle of the human body. ... The Inferior longitudinal muscle is a muscle of the human body. ... The Transversus muscle is a muscle of the human body. ... The Verticalis muscle is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


palate: levator veli palatini - tensor veli palatini - musculus uvulae - palatoglossus - palatopharyngeus | (Gray's s243) The palate is the roof of the mouth in humans and vertebrate animals. ... The Levator veli palatini is a muscle of the human body. ... The Tensor veli palatini muscle (or Tensor palati) is a muscle of the human body. ... The Musculus uvulæ (Azygos uvulæ) arises from the posterior nasal spine of the palatine bones and from the palatine aponeurosis; it descends to be inserted into the uvula. ... The Palatoglossus is a muscle of the human body. ... The Palatopharyngeus muscle is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...


pharynx: pharyngeal constrictor (inferior, middle, superior) - stylopharyngeus - salpingopharyngeus | (Gray's s244) The pharynx (plural: pharynges) is the part of the neck and throat situated immediately posterior to the mouth and nasal cavity, and cranial to the esophagus, larynx, and trachea. ... The Inferior pharyngeal constrictor muscle is a muscle of the human body. ... The Middle pharyngeal constrictor muscle is a muscle of the human body. ... The Superior pharyngeal constrictor muscle is a muscle of the human body. ... Grays Fig. ... The Salpingopharyngeus muscle is a muscle of the human body. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...



 

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