Human Anatomy - Cranial Nerves Lecture 18 PDF

11/18/24 Nervous System Human Anatomy...

11/18/24 Nervous System Human Anatomy BIOL 207 / KINS 207 Peripheral Nervous Chapter 16: Central Nervous System (CNS) System (PNS) Cranial Nerves Brain Spinal cord Everything else November 19, 2024 Cranial Spinal Peripheral Forebrain Midbrain Hindbrain Nerves Nerves Ganglia 1 2 The Cranial Nerves The Cranial Nerves Cranial Nerves Olfactory bulb, Olfactory tract olfactory nerve (I) Optic nerve u Spinal nerves: Emerge from the spinal cord (II) u Cranial nerves: Emerge from the brain\ Oculomotor nerve (III) Optic chiasm Trochlear nerve Infundibulum u There are 12 pairs of cranial nerves (IV) Trigeminal nerve (V) u These nerves innervate the periphery Abducens nerve (VI) Facial nerve u Pure motor, pure sensory, or mixed (both) (VII) Vestibulocochlear nerve (VIII) u They are numbered beginning at the anterior aspect of the Glossopharyngeal nerve (IX) brain Vagus nerve (X) u They are numbered in Roman Numerals CN I to XII Hypoglossal nerve (XII) Accessory nerve (XI) 3 4 1  11/18/24 * Parasympathetic Cranial Nerves The Olfactory Nerves – CN I Olfactory Ganglion Left olfactory bulb (termination of olfactory nerve) Olfactory tract (to olfactory cortex of cerebrum) Olfactory Olfactory nerve (I) nerve fibers Cribriform plate of ethmoid Olfactory epithelium IX 5 7 The Olfactory Nerves – CN I u Function: Pure sensory (smell) u Origin: Olfactory epithelium (receptors) u Foramen: Olfactory foramina within the cribriform plate u Destination: Olfactory bulbs u Olfactory nerves (I) enter bundles called olfactory bulbs u Ganglion u Axons proceed to destination via olfactory tracts u Primary olfactory cortex- temporal lobe u ONLY sense that bypasses the thalamus © 2018 Pearson Education, Inc. Damage or disease à hyposmia and or anosmia (reduced or absence) 8 9 2  11/18/24 The Optic Nerves – CN II The Optic Nerves – CN II u Function: Pure sensory (vision) Right Left u Origin:Retina (receptors) E ye u Foramen: Optic canal O lfactory bulb u Destination: Diencephalon, then to occipital lobe Optic O lfactory tract nerve Optic u Optic nerves (CN II) from the retina cross (to chiasm P ituitary gland a certain degree) the optic chiasm Optic u The nerves continue to their destination via tract M esencephalon Lateral geniculate the optic tracts à thalamus à primary (cut) nucleus (in thalam us) visual cortex u Visual fields projected onto visual cortex in an inverted fashion O ptic projection uUpper visual field à inferior portion uLower visual field à superior portion fibers Damage or disease à defects in vision V isual cortex (in occipital lobes) 10 11 The Oculomotor Nerves – CN III The Oculomotor Nerves – CN III u Mixed motor nerve u Function: Oculomotor u Somatic motor control à extra-ocular eye muscles Superior ner ve (III) O p tic O ptic T ro c h le a r usuperior,inferior, medial rectus, inferior oblique/levator rectus palpebrae superioris Superior n e rve (II) chiasm n e rve (IV ) oblique Trochlea u Parasympathetic motor control Levator uautonomic fibers that synapse in the ciliary ganglion palpebrae superioris uPostganglionic fibers à pupillary constriction Trigem inal nerve (V ), cut u Origin: Midbrain u Foramen: Superior orbital fissure Inferior V estibulocochlear nerve (V III), cut oblique Facial nerve Damage or disease à Pupil dilation (mydriasis) (V II), cut Inferior C iliary Medial Lateral Abducens n e rve (V I) rectus ganglion rectus rectus (cut) à opthalmoplegia (eye movement weakened/paralyzed) SO4 LR6 (exceptions) 12 13 3  11/18/24 The Trochlear Nerves – CN IV The Trochlear Nerves – CN IV u Function: Pure motor ucontrols the superior oblique eye muscle Superior u Origin: midbrain rectus O p tic O ptic Oculomotor Trochlear u Foramen: superior orbital fissure Superior n e rve (II) chiasm nerve (III) ner ve (IV) oblique u Destination: superior oblique muscle Trochlea Levator u Smallest cranial nerve palpebrae superioris Trigem inal nerve (V ), cut Inferior oblique V estibulocochlear nerve (V III), cut Isolated damage is uncommon Facial nerve (V II), cut Inferior C iliary Medial Lateral Abducens rectus ganglion rectus n e rve (V I) rectus (cut) 14 15 Trigeminal Nerve (V) Trigeminal Nerve (V) u Mixed - Both sensory and motor function Superior orbital Ophthalmic Semilunar fissure division ganglion u Trigeminal ganglion u3 branches/divisions Supra-orbital nerves u V1 – Opthalamic nerve à sensory u V2 – Maxillary nerve à sensory III ganglion Ciliary Pons Trigeminal u V3 – Mandibular nerve à sensory & motor Foramen rotundum nerve (V) Maxillary division u Sensory branch is the largest - semilunar ganglion Infra-orbital nerve Foramen ovale u Trigeminal nerves are the largest of the cranial nerves Otic ganglion IX u Pons Mandibular division Pterygopalatine ganglion VII Submandibular ganglion Disease à trigeminal neuralgia (tic douloureux) Lingual nerve Mental nerve 16 17 4  11/18/24 Trigeminal Nerve – CN V1 Opthalamic division (V1) u Ophthalmic division (V1) u Function: Superior orbital Ophthalmic Semilunar fissure division ganglion u Sensations from the forehead, eyelids, nose(center), Frontal and ethmoidal paranasal air sinuses Supra-orbital nerves u Foramen III ganglion Ciliary Pons u Superior orbital fissure Trigeminal nerve (V) u Destination u Pons u Ciliary ganglion CN III 18 19 Trigeminal Nerve – CN V2 Maxillary Division (V2) u Maxillary division (V2) u Function u Sensations from lower eyelid, cheek, nasal cavity, upper lip, teeth, gums and maxillary air Pons Trigeminal sinus Foramen nerve (V) rotundum Maxillary division u Foramen Infra-orbital nerve u Foramen rotundum u Destination u Pons Pterygopalatine ganglion VII u Pterygopalatine ganglion CN VII 20 21 5  11/18/24 Trigeminal Nerve – CN V3 Mandibular Division (V3) u Mandibular division (V3) – largest! u Function u Somatic sensory: lower gums, teeth, lips, palate, anterior 2/3 of tongue u Somatic motor: controls mastication Pons Trigeminal u Foramen nerve (V) u Foramen ovale u Submandibular ganglion CN VII Foramen ovale u Otic ganglion CN IX Otic ganglion IX Mandibular division Submandibular ganglion VII Lingual nerve Mental nerve 22 23 The Abducens Nerves – CN VI The Abducens Nerves – CN VI u Function: Pure motor ucontrols the lateral rectus eye muscle u Origin: pons S uperior O p tic O ptic O c u lo m o to r T ro c h le a r S uperior rectus n e rve (II) chiasm n e rve (III) n e rve (IV ) u Foramen: superior orbital fissure oblique u Destination: innervates the lateral rectus eye muscle Trochlea Levator palpebrae superioris u Long cranial nerve Trigem inal nerve (V ), cut In ferio r oblique V estibulocochlear nerve (V III), cut Vulnerable to damage! Damage à paralysis of LR (unopposed MR) à medial deviation Facial nerve (V II), cut à patient complains of double vision (diplopia) In ferio r C iliary M edial Lateral rectus Abducens nerve (VI) rectus ganglion rectus (cut) 24 25 6  11/18/24 Facial Nerve – CN VII Facial Nerve – CN VII u Function: mixed (sensory and motor) u Somatic sensory: sensations from the face u Specialsense: taste (anterior 2/3 of tongue) u Somatic motor: controls muscles of facial expression u5 branches u Parasympathetic: Submandibular and pterygopalatine glands 26 27 Facial Nerve – CN VII Vestibulocochlear Nerve – CN VIII u Somatic motor branches: u Temporal branch Vestibulocochlear ner ve (VIII) Semicircular u Zygomatic branch Tympanic cavity canals Vestibular Facial nerve Internal (middle ear) ner ve (VII), cut acoustic canal u Buccal branch u Marginal mandibular branch NV Pons u Cervical branch N VI N VII N IX N XII NX Medulla oblongata Damage or disease à patient may lose taste, salivation (some), N XI or lacrimation à Bell’s palsy Tympanic membrane Auditory tube Cochlea Cochlear ner ve 28 29 7  11/18/24 Vestibulocochlear Nerve – CN VIII Glossopharyngeal Nerve – CN IX u Function: Pure sensory u Balance and hearing u Origin: receptors of the vestibule and cochlea u Foramen: internal acoustic meatus u Destination: pons and medulla oblongata Pons NV N VII N VIII N VI Glossopharyngeal Otic nerve (IX) u Consists of the vestibular nerve and the cochlear nerve ganglion Medulla oblongata Superior ganglion u Vestibular nerve: supplies the semicircular canals + vestibule Inferior ganglion à balance and equilibrium. Pharyngeal branches Parotid gland u Cochlear nerve: supplies the organ of corti (cochlea) à Lingual branch hearing. Carotid branch Damage or disease à meniere’s syndrome (vertigo) Carotid body Carotid sinus Damage or disease à difficulty localizing sounds Common carotid artery 30 31 Vagus Glossopharyngeal Nerve – CN IX n e rve (X ) P ons S uperior pharyngeal M edulla oblongata branch u Function: Mixed Vagus Nerve – A uricular branch to external ear S uperior ganglion CN X Inferior of vagus nerve u Sensory: general (pharynx, palatine tonsils, carotid ganglion of P haryngeal vagus nerve branch sinus, posterior 1/3 of tongue) and special sense of S uperior Internal branch S uperior laryngeal nerve posterior 1/3 of tongue laryngeal E xternal branch nerve R ecurrent C ardiac branches u Somatic motor: swallowing à pharyngeal muscles laryngeal nerve C ardiac plexus u Parasympathetics: salivation à parotid salivary gland u Foramen: jugular foramen u Destination: R ight lung Left lung u Sensory: medulla oblongata u Somatic motor: pharyngeal muscles for swallowing Liver A nterior u Visceral motor: parotid salivary gland vagal trunk S tom ach S pleen u Sensory neurons are in the superior and inferior C eliac P ancreas plexus ganglions C olon S m all intestine Damage or disease à difficulty in swallowing, loss of gag reflex H ypogastric plexus 32 33 8  11/18/24 Vagus Nerve – CN X Accessory Nerve – CN XI u Many essential functions u Function: Mixed (both) Hypoglossal nerve (XII) Trigeminal nerve (V) u Sensory: information from organs to autonomic centers of Accessory nerve (XI) Medulla oblongata the medulla oblongata Internal branch: to palatal, pharyngeal, and laryngeal Cranial root of N XI u Eardrum, baroreceptors muscles with vagus nerve Intrinsic muscles Spinal u Somatic motor: sends information to muscles of the of tongue root of N XI Styloglossus palate and pharynx (CN XI) Genioglossus External branch of N XI u Parasympathetic: respiratory, cardiovascular, and Geniohyoid Spinal cord Hyoglossus digestive organs Hyoid bone u Sensory neurons are in the superior and inferior ganglions Trapezius Thyrohyoid Sternocleidomastoid Sternohyoid Damage or disease is widespread… Sternothyroid Ansa cervicalis (cervical plexus) Omohyoid 34 35 Accessory Nerve – CN XI Hypoglossal Nerve – CN XII u Spinal accessory nerve u Function: Pure motor u Accessory branch with vagus (CN X) uSomatic motor: controls tongue movement u Function: Pure motor u Somatic motor: controls the sternocleidomastoid, u Origin trapezius, palate, pharynx, and larynx muscles uMedulla oblongata u Origin: spinal cord and medulla oblongata u Foramen: jugular foramen u Destination: u internal branch: muscles of the palate, pharynx, and larynx (CNX) u external branch: sternocleidomastoid and trapezius muscles Damage or disease à weakness to shrug shoulders Damage or disease à à resist turning head Tongue paralysis 36 37 9  11/18/24 Using your laptop or phone, visit Socrative: https://www.socrative.com *make this link easily accessible! à SAVE link to your start screen, homepage, favorites, etc… Available apps for IOS and Android > Select Student Login Ø Room Name: KINGSANATOMY Ø Enter your FIRST NAME and YOUR SURNAME (eg. John Doe) > Please answer the questions! 38 10