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The oculomotor nerve is the third of twelve paired cranial nerves. It controls most of the eye movements (cranical nerves IV and VI also do some), constriction of the pupil, and holding the eyelid open. In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. ...
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). ...
Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ...
The medial rectus muscle is a muscle in the orbit. ...
The ciliary muscle is a muscle that affects zonules in the eye (fibers that suspend the lens in position during accommodation), enabling changes in lens shape for light focusing. ...
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. ...
Cranial nerves are nerves that emerge from the brainstem instead of the spinal cord. ...
An eye is an organ that detects light. ...
The oculomotor nerve arises from the anterior aspect of mesencephalon (midbrain). The muscles it controls are the ciliary muscle (affecting accommodation), and all extraocular muscles except for the superior oblique muscle and the lateral rectus muscle. In addition, it supplies parasympathetic fibres - which originate in the Edinger-Westphal nucleus - to the eye via the ciliary ganglion, and thus controls pupil constriction. In biological anatomy, the mesencephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. ...
The ciliary muscle is a muscle that affects zonules in the eye (fibers that suspend the lens in position during accommodation), enabling changes in lens shape for light focusing. ...
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). ...
The extraocular muscles are the six muscles that control the movements of the eye. ...
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 lateral rectus muscle is a muscle in the orbit that abducts the eyeball (makes it move outwards). ...
Anatomy and Physiology of the A.N.S. In contrast to the voluntary nervous system, the involuntary or autonomic nervous system is responsible for homeostasis, maintaining a relatively constant internal environment by controlling such involuntary functions as digestion, respiration, and metabolism, and by modulating blood pressure. ...
The Edinger-Westphal nucleus is the accessory parasympathetic nucleus of the oculomotor nerve, supplying the constricting muscles of the iris. ...
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). ...
In medicine, pupil constriction (also known as the pupillary reflex) is reduction of pupil size. ...
Anatomy of the oculomotor nerve On emerging from the brain, the nerve is invested with a sheath of pia mater, and enclosed in a prolongation from the arachnoid. It passes between the superior cerebellar and posterior cerebral arteries, and then pierces the dura mater in front of and lateral to the posterior clinoid process, passing between the free and attached borders of the tentorium cerebelli. It runs along the lateral wall of the cavernous sinus, above the other orbital nerves, receiving in its course one or two filaments from the cavernous plexus of the sympathetic, and a communicating branch from the ophthalmic division of the trigeminal. It then divides into two branches, which enter the orbit through the superior orbital fissure, between the two heads of the Rectus lateralis. Here the nerve is placed below the trochlear nerve and the frontal and lacrimal branches of the ophthalmic nerve, while the nasociliary nerve is placed between its two rami. The pia mater (Latin: tender mother, itself a translation from Arabic) is the delicate innermost layer of the meninges - the membranes surrounding the brain and spinal cord. ...
The Arachnoid mater is one of the three layers of the meninges, interposed between the dura mater and the pia mater and separated from the pia mater by the subarachnoid space. ...
The tentorium cerebelli (Latin: tent of the cerebellum) is an extension of the dura mater that seperates the cerebellum from the inferior portion of the occipital lobes. ...
The fourth of twelve cranial nerves, the trochlear nerve controls the function of the superior oblique muscle, which rotates the eye towards the nose and also moves the eye downward. ...
The Ophthalmic nerve is one of the three branches of the trigeminal nerve, one of the cranial nerves. ...
The superior ramus, the smaller, passes medialward over the optic nerve, and supplies the Rectus superior and Levator palpebræ superioris. The inferior ramus, the larger, divides into three branches. One passes beneath the optic nerve to the Rectus medialis; another, to the Rectus inferior; the third and longest runs forward between the Recti inferior and lateralis to the Obliquus inferior. From the last a short thick branch is given off to the lower part of the ciliary ganglion, and forms its short root. All these branches enter the muscles on their ocular surfaces, with the exception of the nerve to the Obliquus inferior, which enters the muscle at its posterior border. The optic nerve is the nerve that transmits visual information from the retina to the brain. ...
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). ...
Testing the oculomotor nerve Cranial nerves III, IV and VI are usually tested together. The examiner typically instructs the patient to hold his head still and follow only with the eyes a finger or penlight that circumscribes a large "H" in front of the patient. By observing the eye movements and eyelids, the examiner is able to obtain more information about the extraocular muscles, the levator palpebrae superioris muscle, and cranial nerves III, IV, and VI. Eye movements are the voluntary or involuntary movements of the eye. ...
An eyelid is a thin fold of skin and muscle that covers and protects an eye. ...
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. ...
Since the oculomotor controls most of the eye muscles, it may be easier to detect damage to it. Damage to this nerve, termed oculomotor nerve palsy is known by the down n' out symptoms. The affected eye will be looking downward, because the superior oblique (innervated by CN IV), is unantagonized by the paralyzed superior rectus and inferior oblique and looking outwards, because the lateral rectus (innervated by CN VI) is unantagonized by the paralyzed medial rectus. There will also be strabismus. 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 superior rectus muscle is a muscle in the orbit that elevates, adducts, and rotates the eye medially. ...
The inferior oblique muscle is a muscle in the orbit that adducts (medially rotates) and elevates the eyeball. ...
The lateral rectus muscle is a muscle in the orbit that abducts the eyeball (makes it move outwards). ...
The medial rectus muscle is a muscle in the orbit that adducts the eyeball (makes it move inwards). ...
Strabismus prevents bringing the gaze of both eyes to the same point in space Strabismus, also known as heterotropia, squint, crossed eye, wandering eye, or wall eyed, is a disorder in which the eyes do not point in the same direction. ...
They may show a degree of ptosis, or drooping of the eyelid, because the levator palpebrae superioris muscle (eyelid lifting muscle) is also innervated by the oculomotor nerve. Ptosis is the paralysis of the muscles of the eyelid. ...
The oculomotor nerve also controls the constriction of the pupils. This can be tested in two main ways. By moving a finger towards a person's face to induce accommodation, as well as them going cross-eyed, their pupils should constrict. The human eye The pupil is the central transparent area (showing as black). ...
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). ...
Shining a light into their eyes should also make their pupils constrict. Both pupils should constrict at the same time, independent of what eye the light is actually shone on.
See also Anisocoria is a condition characterized by an unequal size of the pupils. ...
The oculomotor nerve () is the third of twelve paired cranial nerves. ...
External links | Major nerves (also see Peripheral nervous system) | | Cranial nerves: I olfactory | II optic | III oculomotor | IV trochlear | V trigeminal | V1 ophthalmic (lacrimal, frontal, supratrochlear, supraorbital, nasociliary, ciliary ganglion) | V2 maxillary (sphenopalatine ganglion) | V3 mandibular (buccal - auriculotemporal - lingual - inferior alveolar - otic ganglion) | VI abducens | VII facial (chorda tympani, nervus intermedius) | VIII vestibulocochlear (cochlear, vestibular) | IX glossopharyngeal | X vagus (recurrent laryngeal, Alderman's nerve) | XI accessory | XII hypoglossal eMedicine is an online clinical medical knowledge base that was founded in 1996. ...
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. ...
NeuroNames is a system of nomenclature for the brain and related structures. ...
Nerves (yellow) Nerves redirects here. ...
The peripheral nervous system or PNS, is part of the nervous system, and consists of the nerves and neurons that reside or extend outside the central nervous system--to serve the limbs and organs, for example. ...
Cranial nerves are nerves that emerge from the brainstem instead of the spinal cord. ...
The olfactory nerve is the first of twelve cranial nerves. ...
The optic nerve is the nerve that transmits visual information from the retina to the brain. ...
The fourth of twelve cranial nerves, the trochlear nerve controls the function of the superior oblique muscle, which rotates the eye towards the nose and also moves the eye downward. ...
The trigeminal nerve is the fifth (V) cranial nerve, and carries sensory information from most of the face, as well as motor supply to the muscles of mastication (the muscles enabling chewing), tensor tympani (in the middle ear) and other muscles in the floor of the mouth, such as the...
The Ophthalmic nerve is one of the three branches of the trigeminal nerve, one of the cranial nerves. ...
The Lacrimal Nerve is the smallest of the three branches of the ophthalmic. ...
The Frontal Nerve is the largest branch of the ophthalmic, and may be regarded, both from its size and direction, as the continuation of the nerve. ...
The supratrochlear nerve, smaller than the Supraorbital nerve, passes above the pulley of the Obliquus superior, and gives off a descending filament, to join the infratrochlear branch of the nasociliary nerve. ...
The supraorbital nerve arises from the orbit by the supraorbital foramen and supplies the upper eyelid and forehead integuments. ...
The Ophthalmic nerve is one of the three branches of the trigeminal nerve, one of the 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). ...
The Maxillary nerve is one of the three branches of the trigeminal nerve, one of the cranial nerves. ...
The sphenopalatine ganglion is a parasympathetic ganglion found in the spheno-maxillary fossa. ...
The mandibular nerve is the third branch (V3) of the trigeminal nerve. ...
A branch of the mandibular nerve (which is itself a branch of the trigeminal nerve), the buccal nerve transmits sensory information from skin over the buccal membrane (in general, the cheek) and from the second and third molar teeth. ...
The auriculotemporal nerve is a branch of the mandibular nerve (Viii) and supplies motor fibres to the temporomandibular joint and parasympathetic fibres to the parotid glands. ...
The Lingual Nerve supplies the mucous membrane of the anterior two-thirds of the tongue. ...
The inferior alveolar nerve is a branch of the mandibular nerve, which is itself the third branch (V3) of the fifth cranial nerve, the trigeminal nerve (cranial nerve V). ...
The Otic Ganglion is a parasympathetic ganglion located immediately below the foramen ovale. ...
The sixth out of twelve cranial nerves, the abducens nerve controls the lateral rectus muscle - this means that the action of this nerve controls each eyes ability to look laterally (away from the midline). ...
The facial nerve is seventh of twelve paired cranial nerves. ...
The chorda tympani are nerves of special sensation given off the facial nerve (VII) inside the skull. ...
The nervus intermedius, or intermediate nerve, is the part of the facial nerve (cranial nerve VII) located between the motor component of the facial nerve and the vestibulocochlear nerve (cranial nerve VIII). ...
The vestibulocochlear nerve is the eighth of twelve cranial nerves and also known as the auditory nerve. ...
The Cochlear nerve (n. ...
The Vestibular nerve is one of the two branches of the Vestibulocochlear nerve (the cochlear nerve is the other. ...
The glossopharyngeal nerve is the ninth of twelve cranial nerves. ...
The vagus nerve is tenth of twelve paired cranial nerves and is the only nerve that starts in the brainstem (somewhere in the medulla oblongata) and extends all the way down past the head, right down to the abdomen. ...
The recurrent laryngeal nerve is a branch of the vagus nerve (the tenth cranial nerve) which supplies motor function and sensation to the larynx (voice box). ...
The Auricular branch of the tenth cranial or vagus nerve is often termed the Aldermans nerve. ...
The accessory nerve is the eleventh of twelve cranial nerves. ...
The hypoglossal nerve is the twelfth cranial nerve. ...
Posterior spinal nerves: greater occipital The term spinal nerve generally refers to the mixed spinal nerve, which is formed from the dorsal and ventral roots that come out of the spinal cord. ...
The greater occipital nerve is a spinal nerve arising between the first and second cervical vertebrae, along with the lesser occipital nerve. ...
C1-C4 - Cervical plexus: lesser occipital | greater auricular | lesser auricular | phrenic | ansa cervicalis The cervical plexus is a plexus of the ventral roots of the first four cervical spinal nerves which are located from C1 to C4 cervical segment near the neck. ...
The lesser occipital nerve is a spinal nerve arising between the first and second cervical vertebrae, along with the greater occipital nerve. ...
The greater auricular nerve originates from the cervical plexus, composed of branches of spinal nerves C2 and C3. ...
The lesser auricular nerve originates from the cervical plexus, composed of branches of spinal nerves C2 and C3. ...
The phrenic nerve arises from the third, fourth, and fifth cervical spinal nerves (C3-C5). ...
The ansa cervicalis (or ansa hypoglossi in older literature) is a loop of nerves that are part of the cervical plexus. ...
C5-C8, T1 - Brachial plexus: supraclavicular branches (dorsal scapular, suprascapular, long thoracic) | lateral cord (musculocutaneous, lateral antibrachial cutaneous, lateral head of median nerve) | medial cord (ulnar, medial head of median nerve, medial antibrachial cutaneous, medial brachial cutaneous) | posterior cord (axillary, radial) The brachial plexus is an arrangement of nerve fibres (a plexus) running from the spine (vertebrae C5-T1), through the neck, the axilla (armpit region), and into the arm. ...
The dorsal scapular nerve arises from the brachial plexus, specifically from spinal nerves C4 and C5. ...
The Nervus suprascapularis (Suprascapular nerve) is a nerve of the plexus brachialis. ...
The long thoracic nerve supplies motor innervation to the serratus anterior muscle. ...
The Lateral cord is a division of the brachial plexus. ...
The major end branch of the lateral cord, courses inferiorly within the anterior arm, supplying motor fibers to the arm muscles that flex the forearm (the biceps brachii and brachialis). ...
The lateral antibrachial cutaneous nerve (branch of musculocutaneous nerve, also sometimes spelled antebrachial) passes behind the cephalic vein, and divides, opposite the elbow-joint, into a volar and a dorsal branch. ...
Diagram from Grays anatomy, depicting the peripheral nerves of the upper extremity, amongst others the median nerve The median nerve is a nerve that runs down the arm and forearm. ...
The Medial cord is a division of the brachial plexus. ...
Grays Fig. ...
Diagram from Grays anatomy, depicting the peripheral nerves of the upper extremity, amongst others the median nerve The median nerve is a nerve that runs down the arm and forearm. ...
The Medial Antibrachial Cutaneous Nerve (internal cutaneous nerve, also sometimes spelled antebrachial) arises from the medial cord of the brachial plexus. ...
The Medial Brachial Cutaneous Nerve (lesser internal cutaneous nerve; nerve of Wrisberg) is distributed to the skin on the ulnar side of the arm. ...
The Posterior cord is a division of the brachial plexus. ...
The axillary nerve is a nerve of the human body, that comes off the posterior cord of the brachial plexus at the level of the axilla (armpit) and carriers nerve fibers from C5 and C6. ...
The radial nerve is a nerve in the human body, that supplies the arm, the forearm and the hand. ...
T2-T11: intercostal The thoracic spinal nerves T3 through T12. ...
T12, L1-L5 - Lumbar plexus: iliohypogastric | ilioinguinal | genitofemoral | lateral femoral cutaneous | femoral | obturator Grays Fig. ...
The Iliohypogastric Nerve arises from the first lumbar nerve. ...
The Ilioinguinal Nerve, smaller than the Iliohypogastric nerve, arises with it from the first lumbar nerve. ...
In human anatomy, the genitofemoral nerve originates from the upper part of the lumbar plexus of spinal nerves. ...
The Lateral Femoral Cutaneous Nerve (external cutaneous nerve) arises from the dorsal divisions of the second and third lumbar nerves. ...
The Femoral Nerve supplies innervation the anterior portion of the leg. ...
The Obturator Nerve arises from the ventral divisions of the second, third, and fourth lumbar nerves; the branch from the third is the largest, while that from the second is often very small. ...
S1-S4 - Sacral plexus: gluteal | posterior femoral cutaneous | tibial | sciatic | sural | common peroneal In human anatomy, the Sacral plexus refers to the nerve plexus emerging from the sacral vertebrae (S1-S4), and which provides nerves for the pelvis and lower limbs. ...
The Superior Gluteal Nerve () arises from the dorsal divisions of the fourth and fifth lumbar and first sacral nerves: it leaves the pelvis through the greater sciatic foramen above the Piriformis, accompanied by the superior gluteal vessels, and divides into a superior and an inferior branch. ...
The Posterior Femoral Cutaneous Nerve (small sciatic nerve) is distributed to the skin of the perineum and posterior surface of the thigh and leg. ...
The Tibial Nerve The tibial nerve passes through the popliteal fossa to pass below the arch of soleus. ...
The sciatic nerve is a large nerve that runs down the lower limb. ...
The sural nerve (short saphenous nerve), formed by the junction of the medial sural cutaneous with the peroneal anastomotic branch, passes downward near the lateral margin of the tendo calcaneus, lying close to the small saphenous vein, to the interval between the lateral malleolus and the calcaneus. ...
The Common peroneal nerve is a branch of the Sciatic nerve. ...
S2-S5 - Pudendal plexus: perforating cutaneous | pudendal | visceral | muscular | anococcygeal The pudendal plexus is not sharply marked off from the sacral plexus, and as a consequence some of the branches which spring from it may arise in conjunction with those of the sacral plexus. ...
The Perforating Cutaneous Nerve usually arises from the posterior surface of the second and third sacral nerves. ...
The pudendal nerve is responsible for orgasm, urination, and defecation in both sexes. ...
The Visceral Branches arise from the third and fourth, and sometimes from the second, sacral nerves, and are distributed to the bladder and rectum and, in the female, to the vagina; they communicate with the pelvic plexuses of the sympathetic. ...
The Muscular Branches are derived from the fourth sacral, and supply the Levator ani, Coccygeus, and Sphincter ani externus. ...
Anococcygeal Nerves: The fifth sacral nerve receives a communicating filament from the fourth, and unites with the coccygeal nerve to form the coccygeal plexus. ...
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