Cranial nerves
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| ANATOMY EXAM 3 STUDY GUIDE – HEAD & NECK
CRANIAL NERVES
MUSCLES (53)
MNEMONICS/STUDY TIPS LAB 1: TRIANGLES & ROOT OF NECK Mnemonic – Carotid sheath contents: I see 10 CCs in the IV I see = Internal Carotid artery 10 = CN X (vagus nerve) (posterior) CC = Common Carotid artery (medial) IV = Internal Jugular Vein (lateral) Relations of important nerves and vessels to the anterior scalene muscle Structures passing anterior to anterior scalene Vagus n. Phrenic n. Thyrocervical trunk branches Subclavian v. Structures passing posterior to anterior scalene Brachial plexus Subclavian a. LAB 2: FACE, SCALP, & PAROTID REGION Mnemonic – Motor branches of the facial nerve (CN VII): To Zanzibar By Motor Car OR Two Zebras Bit My Coccyx Temporal Zygomatic Buccal Marginal mandibular Cervical Mnemonic – Scalp nerve supply: GLASS Greater occipital/Great auricular Lesser occipital Auriculotemporal Supratrochlear Supraorbital Scalp blood supply External carotid artery branches Occipital Posterior auricular Superficial temporal Internal carotid artery branches Supraorbital Supratrochlear Mnemonic – Innervation of muscles Facial nerve innervates muscles of facial expression Mandibular nerve innervates muscles of mastication Mnemonic – External carotid artery branches (in ascending order): Some Angry Lady Figured Out PMS Superior thyroid Ascending pharyngeal Lingual Facial Occipital Posterior auricular Maxillary Superficial temporal Mnemonic – Scalp Layers: SCALP Skin Connective tissue Aponeurosis Loose areolar tissue Pericardium LAB 3: CRANIAL CONTENTS, REFLECTION OF HEAD, PHARYNX Epidural hematoma Anterior branch of middle meningeal artery (MMA) courses superiorly to cross pterion Trauma to side of head may cause fractures of bones forming the pterion and consequently rupture the MMA located in this region Since MMA course between dura and calvaria, in epidural space, hemorrhage in this location is called an epidural hematoma Subdural hematoma A blow to the head the jerks the brain inside the skull can cause the tearing of a cerebral vein, usually as it enters the superior sagittal sinus Since cerebral veins course between the dura and arachnoid maters, a hemorrhage in this location is called a subdural hematoma Clinical correlation – hematomas on CTs Epidural hematomas: lens shape Subural hematomas: crescent shape Subarachnoid hematomas: conform to the shape of sulci Arachnoid granulations Projections of subarachnoid space that serve to return CSF to the venous system On inner aspect of the calvaria you will notice small shallow depressions The depressions are caused by the arachnoid granulations Clinical correlation – Middle Meningeal artery Its anterior branch crosses the area of the pterion Fractures through this area result in tearing of the middle meningeal artery with consequence of an epidural hematoma Mnemonic – foramen ovale contents: OVALE Otic ganglion (just inferior) V3 Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramina in posterior cranial fossa: all structures pass through temporal or occipital bones Internal auditory meatus – CN VII, VIII Jugular foramen – CN IX, X, XI, jugular vein Hypoglossal canal – CN XII Foramen magnum – spinal roots of CN XI, brain stem, vertebral arteries Cisterns Name of areas where subarachnoid space is enlarged Dural folds Tentorium cerebelli – separates the cerebellar lobe from the corresponding occipital pole of the cerebral hemisphere Falx cerebelli – projects between cerebellar hemispheres Falx cerebri – separates the two cerebral hemispheres Mnemonic – cranial nerves: On Old Olympus’ Towering Top, A Fine Von German Vaulted And Hopped Olfactory (I) – sensory Optic (II) – sensory Oculomotor (III) – motor Trochlear (IV) – motor Trigeminal (V) – both Abducent (VI) – motor Facial (VII) – both Vestibulocochlear (VII) – sensory Glossopharyngeal (IX) – both Vagus (X) – both Accessory (XI) – motor Hypoglossal (XII) – motor Mnemonic – cranial nerve modalities: Some Say Marry Money (or money matters) But My Brother Says Big Brains Matter More Sensory Motor Both Circle of Willis arteries supply: ACA (anterior cerebral a.) – medial surface of brain, leg-foot area of motor and sensory cortices MCA (middle cerebral a.) – lateral aspect of brain, Broca’s and Wernicke’s speech areas Ant. Communicating a. – most common Circle of Willis aneurysm, may cause visual field defects Post. Communicating a. – common area of aneurysm, may cause CN III palsy Clinical correlation – signs of stroke Stroke of anterior circle – general sensory and motor dysfunction, aphasia Stroke of posterior circle – vertigo, ataxia, visual deficits, coma Clinical correlation – pulsating exophthalmos In fractures of the base of the skull, the ICA (internal carotid a?) may rupture within the cavernous sinus, forming an arteriovenous fistula This creates reflux of blood from the cavernous sinus into the ophthalmic veins, which normally drain the orbital cavity As a result, eye will appear protruded, engorged, and will pulsate Mnemonic – structures passing through cavernous sinus CN III, IV, V1, and V2 pass through it (in that order from superior to inferior) attached to the lateral wall, while CN VI is “free-floating” and not attached to the wall of the cavernous sinus The cavernous portion ot eh ICA is also here Memonic – foramina through which CN V exits: divisions of the CN V exit owing to Standing Room Only Superior orbital fissure – V1 Foramen Rotundum – V2 Foramen Ovale – V3 Foramina in the middle cranial fossa – all structures pass through the sphenoid bone Optic canal – CN II, ophthalmic artery, central retinal vein Superior orbital fissure – CN III, IV, V1, VI, ophthalmic vein Foramen rotundum – CN V2 Foramen ovale – CN V3 Foramen spinosum – middle meningeal a. LAB 4: BISSECTION OF THE HEAD, PHARYNX & TEMPORAL REGION Borders of the infratemporal fossa Lateral – ramus of the mandible Anterior – posterior aspect of the maxilla Superior – inferior orbital fissure Medial – pterygopalatine fossa and the lateral pterygoid of the sphenoid bone Roof – greater wing of the sphenoid bone Contents of the infratemporal fossa Mandibular nerve (V3) – transmitted through the foramen ovale Middle meningeal vessels Sphenomandibular ligament, which attaches close to the spine of the sphenoid bone Medial and lateral pterygoid muscles Muscles of mastication – all innervated by CN V3 Lateral pterygoid Masseter Medial pterygoid Temporalis Mnemonic – branches of the maxillary artery: MIDtown Mice Bite People’s Smelly Instep Middle meningela Inferior alveolar Deep temporal Masseteric Buccal Posterior superior alveolar Sphenopalatine (in the pterygopalatine fossa) Infra orbital (in the pterygopalatine fossa) Do not confuse buccal branch of CN V and VII Buccal of V3 is sensory and GSA Buccal of VII is motor to the buccinator muscle and SVE Schematic for tympanic nerve pathway Tympanic nerve arises from CN IX and emerges with it from the jugular foramen Tympanic nerve enters the middle ear via the tympanic canaliculus in the petrous part of the temporal bone Tympanic nerve forms the tympanic plexus on promontory of the middle ear The lesser petrosal nerve arises as a branch of the tympanic plexus Lesser petrosal nerve penetrates the roof of a tympanic cavity (tegmen tympani) to enter middle cranial fossa Lesser petrosal nerve exits the cranium through the foramen ovale Preganglionic parasympathetic (GVE) fibers from the lesser petrosal nerve synapse in the otic ganglion Postganglionic fibers pass to the parotid gland via branches of the auriculotemporal nerve (branch of V3) LAB 5: ORBIT, PTERYGOPALATINE FOSSA & NASAL REGION Clinical correlation – Central retinal artery It’s occlusion leads to instant and total blindness of the affected eye Superior, Middle, and Inferior Meatus Sphenoidal sinus drains into superior meatus Middle meatus contains the Hiatus semilunaris Nasolacrimal duct drains into inferior meatus LAB 6: MOUTH, TONGUE AND LARYNX Mneumonic – muscles innervated by the Hypoglossus nerve, CN XII: All muscles with the root “-glossus” (except palatoglossus – CN X) are innervated by CN XII Mneumonic – muscles inervated by Vagus nerve, CN X All muscles with the root “-palat” (except tensor veli palatini – CN V2) are inervated by CN X Directory: mybusm -> files -> 2009 2009 -> Anatomy exam 1 review – muscles, joints, ligaments back muscles (11) Download 176.28 Kb. 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