Cranial Nerves (I-XII) PDF

Question Answer Name sensory nerves ? – !`Olfactory nerve – !aOptic nerve – !g Vestibuloco...

Question Answer Name sensory nerves ? – !`Olfactory nerve – !aOptic nerve – !g Vestibulocochlear nerve Name motor nerves ? – !b Oculomotor nerve – !c Trochlear nerve – !eAbducent nerve – !j Accessory nerv – !k Hypoglossal nerve Name mixed nerves ? – !dTrigeminal nerve, – !f Facial nerve, – !hGlossopharyngeal nerve – !iVagus nerve Where does the Olfactory Nerve arise from? The olfactory epithelium. Through which bone does the Olfactory Nerve pass and The cribriform plate of the ethmoid bone and terminate In the primary olfactory cortex. where does it terminates ? What is the function of the Olfactory Nerve? To carry afferent impulses for the sense of smell. What is the impact of COVID-19 on the olfactory system? It can lead to anosmia (loss of smell). Where does Cranial Nerve II arise from? The retina of the eye. Through which structure do the optic nerves pass? The optic canals and meet At the optic chiasm. Where do the optic nerves continue to after the optic To the thalamus where they synapse and then to the To the visual cortex in the occipital chiasm? lobe How many nerve fibers does the optic nerve bundle carry? More than 1 million. What happens in glaucoma that leads to optic nerve The fluid pressure inside the eyes slowly rises and damages the optic nerve. damage? What are the causes of optic neuritis ? Infections, immune-related illnesses such as multiple sclerosis, and sometimes unknown causes. ---NOTE---: neuritis means inflammation What are the causes of optic nerve atrophy? Poor blood flow to the eye, disease, trauma, or exposure to toxic substances. ---NOTE---: atrophy MEANS decreasing in size What are optic nerve head drusen? Pockets of protein and calcium salts that build up in the optic nerve over time. Where do the fibers of Oculomotor nerve extend from and From the ventral midbrain, and go through The superior orbital fissure. go through ? What are the functions of the Oculomotor nerve? Raising the eyelid, directing the eyeball, constricting the iris, and controlling lens shape. Which functions of the Oculomotor nerve are Constricting the iris and controlling lens shape. parasympathetically controlled? these actions are regulated by the part of the nervous system Where are the parasympathetic cell bodies located for the In the ciliary ganglia. Oculomotor nerve? What is oculomotor paralysis? It is a condition characterized by the inability to move the eyes in certain directions due to damage to the oculomotor nerve. Path of Trochlear nerve? The dorsal midbrain and enter the orbit through Superior orbital fissures. Which muscle does the Trochlear nerve innervate? Superior oblique muscle. Through which openings do the fibers of Trigeminal nerve Superior orbital fissure (V1), foramen rotundum (V2), and foramen ovale (V3). run to the pons? What type of impulses does the Trigeminal nerve convey Sensory impulses Question Answer from various areas of the face? - forehead and eye by ophthalmic - face by maxillary What is the function of the motor fibers supplied by the Mastication (temporalis, masseter, and lateral and medial pterygoid muscles) by Trigeminal nerve? mandibular nerve V3 What structures of the eye does the ophthalmic nerve Cornea, ciliary body, lacrimal gland, and conjunctiva. supply sensory innervation to? Apart from the eye, which other parts of the body does the Mucous membrane of the nasal cavity, and the skin of the eyelids, eyebrow, forehead, ophthalmic nerve supply nerves to? and nose. What infection can cause painful sensations along the path Infections of the trigeminal ganglion by the herpes zoster virus (shingles). of the trigeminal nerve? Which areas are mostly affected by infections of the Areas innervated by the ophthalmic nerve. trigeminal ganglion? What are the branches of the Maxillary nerve? Zygomatic nerve, Nasopalatine nerve, Posterior superior alveolar nerve, Greater and lesser palatine nerves, Pharyngeal nerve. Through which opening does the Zygomatic nerve pass? Inferior orbital fissure. How is trigeminal neuralgia characterized? By severe pain in the face and jaw. What can lesions of the maxillary nerve cause? Intense hot and cold sensations in the teeth. Where does the main trunk of the mandibular nerve give In the infratemporal fossa, near the skull base. off sensory and motor branches? Which muscles receive motor branches from the tensor tympani, and tensor veli palatini muscles , Muscles involved in mastication, such mandibular nerve? as the temporalis, masseter, and lateral and medial pterygoid muscles Mandibular nerve pic Where does the motor root of the mandibular nerve Motor nucleus of trigeminal nerve. originate from? What does the mandibular division of the nerve pass Medial pterygoid and tensor veli palatyni muscles. between? What branches does the anterior division of the mandibular Motor branches for the masticatory muscles and the buccal nerve. nerve produce? What branches does the posterior division of the Auriculotemporal, lingual, and inferior alveolar nerves. mandibular nerve divide into? Which muscles does the posterior division of the Anterior belly of the digastric muscle and the mylohyoid muscle. mandibular nerve innervate? Where do the fibers of Cranial Nerve VI leave from? The inferior pons. Through which opening do the fibers of Cranial Nerve VI Superior orbital fissure. enter the orbit? Which muscle does Cranial Nerve VI primarily innervate? Lateral rectus muscle by abducting the eye Abducent Nerve pathway pic What happens if there is an injury to the Abducens nerve? It can result in weakness or paralysis of the lateral rectus muscle, leading to difficulty in moving the eye laterally. Through which structure do the fibers of Cranial Nerve VII The internal acoustic meatus and They emerge through the stylomastoid foramen to the travel? lateral aspect of the face. What are the motor functions of Cranial Nerve VII? Facial expression, and the transmittal of autonomic impulses to lacrimal and salivary glands. What is the sensory function of Cranial Nerve VII? Taste from the anterior two-thirds of the tongue via chorda tympani What are the motor functions associated with the facial Muscles of facial expression, posterior belly of the digastric, stylohyoid, and stapedius nerve? muscles. Question Answer Which glands are supplied by the parasympathetic function Submandibular and sublingual salivary glands, nasal, palatine, and pharyngeal mucous of the facial nerve? glands, lacrimal glands. Where do the two roots of the facial nerve travel through? The internal acoustic meatus, a 1cm long opening in the petrous part of the temporal bone. What important events occur within the facial canal ( canal The two roots fuse to form the facial nerve, and the nerve forms the geniculate btw nternal acoustic meatus and stylomastoid foramen) ganglion. What does the facial nerve give rise to within the facial Greater petrosal nerve (parasympathetic fibres to mucous glands and canal. lacrimal gland), nerve to stapedius, and chorda tympani. Facial nerve pathway pic What is the first extracranial branch of the facial nerve? The posterior auricular nerve. How many branches does the facial nerve split into within Five branches. the parotid gland? ---Note---: facial nerve does not innervate parotid gland ,but glossopharyngeal What are the five branches into which the facial nerve Temporal branch, Zygomatic branch, Buccal branch, Marginal mandibular branch, terminates within the parotid gland? Cervical branch. What are the responsibilities of the branches of the facial Innervating the muscles of facial expression. nerve within the parotid gland? What happens to the muscles of facial expression when They will be paralyzed or severely weakened. intracranial lesions occur? What are the symptoms of an intracranial lesion of the Reduced salivation and loss of taste on the ipsilateral 2/3 of the tongue. facial nerve related to the Chorda tympani? What symptom is associated with the Nerve to stapedius in Ipsilateral hyperacusis (hypersensitive to sound). an intracranial lesion of the facial nerve? What is the symptom related to the Greater petrosal nerve Ipsilateral reduced lacrimal fluid production. in an intracranial lesion of the facial nerve? What is the most common cause of an intracranial lesion of Infection related to the external or middle ear. the facial nerve? What is the term for the disease when no definitive cause Bell’s palsy when there are more than one symptoms. can be found for an intracranial lesion of the facial nerve? What function of the facial nerve is affected by extracranial Only the motor function. lesions? What are the effects of extracranial lesions on the facial Paralysis or severe weakness of the muscles of facial expression. nerve? What are the various causes of extracranial lesions of the Parotid gland pathology, infection of the nerve, compression during forceps delivery, and facial nerve? idiopathic (Bell’s palsy). How can compression during forceps delivery lead to The neonatal mastoid process is not fully developed and does not provide complete extracranial lesions of the facial nerve? protection of the nerve. Where do the fibers of Vestibulocochlear nerve pass The internal acoustic meatus. through? Where do the fibers of Vestibulocochlear nerve enter the At the pons-medulla border. brainstem? What are the two divisions of Vestibulocochlear nerve? Cochlear (hearing) and vestibular (balance). What are the functions of Vestibulocochlear nerve? Solely sensory for equilibrium and hearing. Where does the vestibular component of the The vestibular nuclei complex in the pons and medulla. vestibulocochlear nerve arise from? Where does the cochlear component of the The ventral and dorsal cochlear nuclei, situated in the inferior cerebellar peduncle. vestibulocochlear nerve arise from? Question Answer Through which structure does the vestibulocochlear nerve The internal acoustic meatus of the temporal bone. exit the cranium? What does the vestibulocochlear nerve split into within the The vestibular nerve and the cochlear nerve. distal aspect of the internal acoustic meatus? What does the vestibular and cochlear nerve innervate? The vestibular system of the inner ear, responsible for detecting balance& Cochlea of the inner ear, forming the spiral ganglia which serve the sense of hearing. Where do the fibers of Cranial Nerve IX emerge from? From the medulla and leave the skull via the jugular foramen. What motor functions does Cranial Nerve IX have? Innervates part of the tongue and pharynx, and provides motor fibers to the parotid salivary gland. What sensory functions does Cranial Nerve IX have? Fibers conduct taste and general sensory impulses from the tongue and pharynx. What are the branches of the glossopharyngeal nerve? Thympanic nerve, minor petrosal nerve, carotic branch, muscular branch, pharyngeal branches, and lingual branch. Where is the minor petrosal nerve continuated to? The otic ganglion. What are the areas of innervation for the minor petrosal Tympanic cavity, auditive tube, parotid salivatory gland, and buccales glands. nerve branch of Glosopharyngeal nerve? Where does the carotic branch of the glossopharyngeal Carotic sinus and carotic body. nerve go to? What is the area of innervation for the muscular branch of Stylopharyngeal muscle and the neighbouring membrane of the pharynx. the glossopharyngeal nerve? Muscles of the soft palatine except tensor veli palatini muscle Palantine tonsils Note: vagus innervate most of pharynx muscles except Stylopharyngeal What are the areas of innervation for the lingual branch of Mucous membrane of the posterior (base) third of the tongue - sensory and taste fibers. the glossopharyngeal nerve? What is the effect of palsy of the IX nerve on taste? Loss of taste on the posterior 1/3 of the tongue. What sensation is lost due to palsy of the IX nerve? Loss of the sensation of the soft palate. What are the main motor fibers of the vagus nerve Parasympathetic fibers to the heart, lungs, and visceral organs. responsible for? Through which foramen does this nerve leave the skull? Lateral part of the jugular foramen. With which other cranial nerve does it share a common Cranial Nerve XI (Accessory Nerve). sheath? What does the glossopharyngeal nerve form in the jugular The superior ganglion. foramen? What is Palsy of Vagus nerve? - Soft palate and Uvula deviation - Vocal cord paralysis What are the symptoms of Vagus nerve lesions? Palatal and pharyngeal paralysis, laryngeal paralysis, abnormalities of esophageal motility, gastric acid secretion, gallbladder emptying, heart rate, and other autonomic dysfunction. What forms the Cranial Nerve XI: Accessory? A cranial root emerging from the medulla and a spinal root arising from the superior region of the spinal cord. How does the spinal root of the accessory nerve enter the It passes upward into the cranium via the foramen magnum. cranium? Through which opening does the accessory nerve leave The jugular foramen. the cranium? Which areas does Cranial Nerve XI supply fibers to? Larynx, pharynx, and soft palate. What muscles does Cranial Nerve XI innervate? Trapezius and sternocleidomastoid. Question Answer Where does the cranial root of the accessory nerve join the At its inferior ganglion. vagus nerve? What are the main distributions of the cranial root of the Pharyngeal and recurrent laryngeal branches of the vagus nerve. accessory nerve? Where does the spinal root of the accessory nerve run By the posterior triangle of the neck on the levator scapulae to the trapezius muscle. after entering the deep surface of the sternocleidomastoid muscle? Which muscles does the accessory nerve supply? Sternocleidomastoid and trapezius muscles. What is the symptom of palsy of the XI nerve? Asymmetry of the shoulder Winged scapula. What does the Hypoglossal nerve innervate? Both extrinsic and intrinsic muscles of the tongue. What does the meningeal branch of XII innervate? The occipital sinus. What does the descending muscular branch of XII The intrinsic and extrinsic muscles of the tongue. innervate? What is the effect of palsy of the XII nerve? Atrophy of ipsilateral muscles of the tongue and deviation toward the affected side and Speech disturbances.