• orbital
  • The US allows the evaluation of the extrinsic oculomotor muscles, although only little information about the optical nerve at the orbital apex and the degree of proptosis can be obtained. (eurorad.org)
  • Surgical Excision of Orbital Cysticercosis Lodged in Superior Oblique Muscle: Clinical Case Report. (nih.gov)
  • A contrast-enhanced computed tomographic scan of the orbit revealed the presence of a well-defined hypodense cystic lesion within the right superior oblique muscle.The patient was diagnosed with orbital space-occupying mass with acquired Brown syndrome. (nih.gov)
  • The orbit and its contents in 20-22 mm embryos of the North American actinopterygian Amia calva L., with particular reference to the evolutionary significance of an aberrant, nonocular, orbital muscle innervated by the oculomotor nerve and notes on the metameric character of the head in craniates. (wikipedia.org)
  • The last muscle is the inferior oblique, which originates at the lower front of the nasal orbital wall, and passes under the LR to insert on the lateral, posterior part of the globe. (wikipedia.org)
  • pathway
  • The direct proprioceptive pathway in the visual system begins at the oculomotor muscle. (posturmed.com)
  • It should be borne in mind, however, that the branched structure of the oculomotor nerve means that damage sustained at different points along its pathway, or damage caused in different ways (compression versus loss of blood supply, for example), will result in different muscle groups or, indeed, different individual muscles being affected, thus producing different presentation patterns. (wikipedia.org)
  • lacrimal
  • This is done either directly or indirectly, as in the lateral rectus muscle, via the lacrimal artery, a main branch of the ophthalmic artery. (wikipedia.org)
  • movements
  • Most commonly involved are facial muscles and the extraocular muscles, rarely the hands are performing mirror movements. (wikipedia.org)
  • The most common symptoms of facial synkinesis include: Eye closure with volitional contraction of mouth muscles Midfacial movements with volitional eye closure Neck tightness (Platysmal contraction) with volitional smiling Hyperlacrimation(also called Crocodile Tears) A case where eating provokes excessive lacrimation. (wikipedia.org)
  • Vertical movements require the coordinated action of the superior and inferior rectus muscles, as well as the oblique muscles. (wikipedia.org)
  • The oblique muscles are also primarily responsible for torsional movements. (wikipedia.org)
  • In addition to the movement of muscles, numerous areas in the brain contribute to involuntary and voluntary eye movements. (wikipedia.org)
  • parasympathetic
  • Compressive oculomotor nerve damage could result in compression of the parasympathetic fibers before any disruption of the motor fibers occurs, since the parasympathetic fibers run on the outside of the nerve. (wikipedia.org)
  • Conversely, parasympathetic stimulation causes contraction of the circular muscle and constriction of the pupil. (wikipedia.org)
  • fibers
  • In this case, the tonic muscle fibers remain in stress because their mechanism to relax is blocked by the proprioceptive system. (posturmed.com)
  • 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. (wikipedia.org)
  • The iris dilator muscle fibers course radially through the iris. (wikipedia.org)
  • There are two types of muscle that control the size of the iris: the iris sphincter, composed of circularly arranged muscle fibers, and the iris dilator, composed of radially arranged muscle fibers. (wikipedia.org)
  • An alpha motor neuron and the muscle fibers it innervates is a motor unit. (wikipedia.org)
  • The primary output of α-MNs is to extrafusal muscle fibers. (wikipedia.org)
  • contraction
  • Loss of motor function results in dorsiflexion, contractures of the toes, loss of the interosseous muscle function that leads to contraction of the digits, so-called hammer toes. (wikipedia.org)
  • For example, voluntary smiling will induce an involuntary contraction of the eye muscles causing the eye to squint when smiling. (wikipedia.org)
  • The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction. (wikipedia.org)
  • This posterior medial angle causes the eye to roll with contraction of either the superior rectus or inferior rectus muscles. (wikipedia.org)
  • Sympathetic stimulation of the adrenergic receptors causes the contraction of the radial muscle and subsequent dilation of the pupil. (wikipedia.org)
  • One of them is the autonomic constriction and contraction of certain muscles. (wikipedia.org)
  • spasm
  • Drugs such as tropicamide are used in medicine to permit examination of the retina and other deep structures of the eye, and also to reduce painful ciliary muscle spasm (see cycloplegia). (wikipedia.org)
  • Surgical
  • Surgical exploration of the superior oblique muscle was performed, and the cyst was removed from the eye and confirmed by histopathological examination. (nih.gov)
  • After surgery, an ocular motility examination revealed orthotropia in the primary position and downgaze, with mild restriction in levoelevation.Surgical removal could substitute for medical therapy when the cysticercosis is lodged in the superior oblique muscle, although, prior to surgery, important factors, such as patient requirements, surgical skills of the surgeon, and cyst placement, should be considered. (nih.gov)
  • Brain
  • Brain due to oculomotor muscles makes accommodation. (eyesvisions.com)
  • David A. Robinson discovered that the eye muscles require this dual velocity-position drive, and also proposed that it must arise in the brain by mathematically integrating the velocity signal and then sending the resulting position signal to the motoneurons. (wikipedia.org)
  • A brain catastrophe, or a rapidly increasing brain mass, can cause compression of the oculomotor nerve. (wikipedia.org)
  • Such damage could be a sign or symptom of an underlying disease such as diabetes mellitus, a brain tumor, a pancoast tumor (apex of lung) and diseases which may cause weakness in muscles or nerve damage, such as myasthenia gravis or oculopharyngeal muscular dystrophy. (wikipedia.org)
  • extrinsic
  • The CT scan showed a severe proptosis (distance from the bizigomatic line 29-30 mm, Fig. 1a), an increased thickness of all extrinsic oculomotor muscles, especially the medial straight muscle (12 mm on the right side and 11 mm on the left side Fig. 1b) and the superior straight muscle (8 mm on the right side and 10 mm on the left side, Fig. 1c). (eurorad.org)
  • CT and MR allow for a careful evaluation of the degree of proptosis and the extrinsic muscle thickness, and give information about the indirect signs of a compressive optic neuropathy. (eurorad.org)
  • In particular, an MRI offers more possibilities for the tissue typing because it shows early degenerative phenomena of the extrinsic muscles and structural variations of the postorbital cellular flail tissue. (eurorad.org)
  • Inferior oblique muscle Extrinsic eye muscle. (wikipedia.org)
  • innervation
  • 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. (wikipedia.org)
  • Yet another interpretation of the coelacanthiform basicranial muscle and its innervation. (wikipedia.org)
  • Below is a table of each of the extraocular muscles and their innervation, origins and insertions, and actions. (wikipedia.org)
  • Esotropia
  • CONCLUSIONS: Topical anesthesia requires a smaller amount of surgery and number of operated muscles to correct esotropia compared with classic surgery guidelines adapted to the surgeon's personal technique. (biomedsearch.com)
  • anterior
  • The four rectus muscles attach directly to the front half of the eye (anterior to the eye's equator), and are named after their straight paths. (wikipedia.org)
  • Each rectus muscle receives blood from two anterior ciliary arteries, except for the lateral rectus muscle, which receives blood from only one. (wikipedia.org)
  • lens
  • A year later, or maybe half a year after laser correction in nearsight patients muscles will be stronger and stronger pressure on the eyes, and a farsight patients muscles will increasingly pulling back the eyes, such destroying tailored optical system of the lens. (eyesvisions.com)