Gross anatomy of human brain

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slides about basic anatomy of brain with cranial nerves for undergraduates.

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  • The Gordon Research Conference on the Cerebellum will bring together scientists studying the cerebellum at all levels of analysis, with a goal of fostering dialogue among people engaged in different subfields of cerebellar research. The scientific program has been designed to provide a venue for anatomists, electrophysiologists, developmental biologists, and behavioral neuroscientists, and other researchers with interest in the cerebellum to communicate their latest work to one another. Scientific sessions will cover a wide range of topics, including cerebellar development, human cerebellar function, sensorimotor integration, cerebellar connections to the inferior olive and basal ganglia, emerging technologies to study the cerebellum, cerebellar anatomy, synaptic and circuit mechanisms, and the cerebellum in autism, dystonia, and ataxia. Speakers include senior and junior researchers from all over the world, and the meeting will provide opportunities for scientists of diverse backgrounds and career stages to interact and discuss their hypotheses and discoveries with all other attendees, from leading cerebellar scientists to promising trainees. In addition to the thematic sessions, poster sessions will provide opportunities for attendees to present their work, and a subset of submitted abstracts will be selected to permit graduate students and/or postdoctoral fellows to give short talks. The Conference promises to generate a lively and collegial exchange of ideas, cultivate meaningful collaborations, and ultimately lead to a better understanding of the cerebellum in health and disease.
    Weblink http://www.grc.org/programs.aspx?id
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  • The Gordon Research Conference on the Cerebellum will bring together scientists studying the cerebellum at all levels of analysis, with a goal of fostering dialogue among people engaged in different subfields of cerebellar research. The scientific program has been designed to provide a venue for anatomists, electrophysiologists, developmental biologists, and behavioral neuroscientists, and other researchers with interest in the cerebellum to communicate their latest work to one another. Scientific sessions will cover a wide range of topics, including cerebellar development, human cerebellar function, sensorimotor integration, cerebellar connections to the inferior olive and basal ganglia, emerging technologies to study the cerebellum, cerebellar anatomy, synaptic and circuit mechanisms, and the cerebellum in autism, dystonia, and ataxia. Speakers include senior and junior researchers from all over the world, and the meeting will provide opportunities for scientists of diverse backgrounds and career stages to interact and discuss their hypotheses and discoveries with all other attendees, from leading cerebellar scientists to promising trainees. In addition to the thematic sessions, poster sessions will provide opportunities for attendees to present their work, and a subset of submitted abstracts will be selected to permit graduate students and/or postdoctoral fellows to give short talks. The Conference promises to generate a lively and collegial exchange of ideas, cultivate meaningful collaborations, and ultimately lead to a better understanding of the cerebellum in health and disease.
    Weblink http://www.grc.org/programs.aspx?id
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  • Gross anatomy of human brain

    1. 1. DEPT OF NEUROSURGERY, CMCH, LUDHIANA
    2. 2. The Human Brain Master Watermark Image: http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
    3. 3. <ul><li>Students will be able to describe the general structure of the Cerebrum and Cerebral Cortex. </li></ul><ul><li>Students will be able to identify the Cerebrum, the Lobes of the Brain, the Cerebral Cortex, and its major regions/divisions. </li></ul><ul><li>Students will be able to describe the primary functions of the Lobes and the Cortical Regions of the Brain. </li></ul>
    4. 8. Cerebrum - The largest division of the brain. It is divided into two hemispheres, each of which is divided into four lobes. http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif Cerebrum Cerebrum Cerebellum
    5. 9. Cerebral Cortex - The outermost layer of gray matter making up the superficial aspect of the cerebrum. http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg Cerebral Cortex Cerebral Cortex
    6. 10. <ul><li>Cerebral Features: </li></ul><ul><li>Sulci – Small grooves dividing the gyri </li></ul><ul><ul><li>Central Sulcus – Divides the Frontal Lobe from the Parietal Lobe </li></ul></ul><ul><li>Fissures – Deep grooves, generally dividing large regions/lobes of the brain </li></ul><ul><ul><li>Longitudinal Fissure – Divides the two Cerebral Hemispheres </li></ul></ul><ul><ul><li>Transverse Fissure – Separates the Cerebrum from the Cerebellum </li></ul></ul><ul><ul><li>Sylvian/Lateral Fissure – Divides the Temporal Lobe from the Frontal and Parietal Lobes </li></ul></ul><ul><li>Gyri – Elevated ridges “winding” around the brain. </li></ul>
    7. 11. Gyri (ridge) Fissure (deep groove) Sulci (groove) http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
    8. 14. Longitudinal Fissure Transverse Fissure Sylvian/Lateral Fissure Central Sulcus http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_brain.gif Specific Sulci/Fissures:
    9. 15. <ul><li>Frontal </li></ul><ul><li>Parietal </li></ul><ul><li>Occipital </li></ul><ul><li>Temporal </li></ul>* Note: Occasionally, the Insula is considered the fifth lobe. It is located deep to the Temporal Lobe. http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    10. 16. <ul><li>The Frontal Lobe of the brain is located deep to the Frontal Bone of the skull. </li></ul>(Investigation: Phineas Gage) <ul><li>It plays an integral role in the following functions/actions: </li></ul><ul><ul><li>- Memory Formation </li></ul></ul><ul><ul><li>- Emotions </li></ul></ul><ul><ul><li>- Decision Making/Reasoning </li></ul></ul><ul><ul><li>- Personality </li></ul></ul>Investigation (Phineas Gage) Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    11. 17. <ul><li>Orbitofrontal Cortex – Site of Frontal Lobotomies </li></ul><ul><li>Primary Motor Cortex (Precentral Gyrus) – Cortical site involved with controlling movements of the body. </li></ul><ul><li>Broca’s Area – Controls facial neurons, speech, and language comprehension. Located on Left Frontal Lobe. </li></ul><ul><ul><li>Broca’s Aphasia – Results in the ability to comprehend speech, but the decreased motor ability (or inability) to speak and form words. </li></ul></ul><ul><li>Olfactory Bulb - Cranial Nerve I, Responsible for sensation of Smell </li></ul><ul><ul><li>* Desired Effects: </li></ul></ul><ul><ul><ul><li>- Diminished Rage </li></ul></ul></ul><ul><ul><ul><li>- Decreased Aggression </li></ul></ul></ul><ul><ul><ul><li>- Poor Emotional Responses </li></ul></ul></ul>* Possible Side Effects: - Epilepsy - Poor Emotional Responses - Perseveration (Uncontrolled, repetitive actions, gestures, or words)
    12. 18. Primary Motor Cortex/ Precentral Gyrus Broca’s Area Orbitofrontal Cortex Olfactory Bulb Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg Regions Investigation (Phineas Gage)
    13. 19. <ul><li>The Parietal Lobe of the brain is located deep to the Parietal Bone of the skull. </li></ul><ul><li>It plays a major role in the following functions/actions: </li></ul>- Senses and integrates sensation(s) <ul><li>Spatial awareness and perception </li></ul><ul><ul><li>(Proprioception - Awareness of body/ body parts in space and in relation to each other) </li></ul></ul>Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    14. 20. <ul><li>Primary Somatosensory Cortex (Postcentral Gyrus) – Site involved with processing of tactile and proprioceptive information. </li></ul><ul><li>Somatosensory Association Cortex - Assists with the integration and interpretation of sensations relative to body position and orientation in space. May assist with visuo-motor coordination. </li></ul><ul><li>Primary Gustatory Cortex – Primary site involved with the interpretation of the sensation of Taste. </li></ul>
    15. 21. Primary Somatosensory Cortex/ Postcentral Gyrus Primary Gustatory Cortex Somatosensory Association Cortex Regions Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    16. 22. <ul><li>The Occipital Lobe of the </li></ul><ul><li>Brain is located deep to the </li></ul><ul><li>Occipital Bone of the Skull. </li></ul><ul><li>Its primary function is the processing, integration, interpretation, etc. of VISION and visual stimuli. </li></ul>Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    17. 23. <ul><li>Primary Visual Cortex – This is the primary area of the brain responsible for sight -recognition of size, color, light, motion, dimensions, etc. </li></ul><ul><li>Visual Association Area – Interprets information acquired through the primary visual cortex. </li></ul>
    18. 24. Primary Visual Cortex Visual Association Area Regions Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    19. 25. <ul><li>The Temporal Lobes are located on the sides of the brain, deep to the Temporal Bones of the skull. </li></ul><ul><li>They play an integral role in the following functions: </li></ul><ul><ul><li>Hearing </li></ul></ul><ul><ul><li>Organization/Comprehension of language </li></ul></ul><ul><ul><li>Information Retrieval (Memory and Memory Formation) </li></ul></ul>Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    20. 26. <ul><li>Primary Auditory Cortex – Responsible for hearing </li></ul><ul><li>Primary Olfactory Cortex – Interprets the sense of smell once it reaches the cortex via the olfactory bulbs. (Not visible on the superficial cortex) </li></ul><ul><li>Wernicke’s Area – Language comprehension. Located on the Left Temporal Lobe. </li></ul>- Wernicke’s Aphasia – Language comprehension is inhibited. Words and sentences are not clearly understood, and sentence formation may be inhibited or non-sensical.
    21. 27. Primary Auditory Cortex Wernike’s Area Primary Olfactory Cortex (Deep) Conducted from Olfactory Bulb Regions Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    22. 28. <ul><li>Arcuate Fasciculus - A white matter tract that connects Broca’s Area and Wernicke’s Area through the Temporal, Parietal and Frontal Lobes. Allows for coordinated, comprehensible speech. Damage may result in: </li></ul>- Conduction Aphasia - Where auditory comprehension and speech articulation are preserved, but people find it difficult to repeat heard speech. Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg Arcuate Fasciculus
    23. 29. Click the Region to see its Name Korbinian Broadmann - Learn about the man who divided the Cerebral Cortex into 52 distinct regions: http://en.wikipedia.org/wiki/Korbinian_Brodmann Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
    24. 30. Lobes and Structures of the Brain B. A. C. D. E. F. G. http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
    25. 31. Lobes and Structures of the Brain B. A. (groove) C. (groove) D. E. F. G. B. Frontal Lobe G. Parietal Lobe F. Occipital Lobe D. Temporal Lobe A. Central Sulcus (groove) E. Transverse Fissure C. Sylvian/Lateral Fissure http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
    26. 32. Cortical Regions A. B. C. D. E. F. G. H. I. J. K. http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
    27. 33. Cortical Regions A. B. C. D. E. F. G. H. I. J. K. A. Primary Motor Cortex/ Precentral Gyrus B. Broca’s Area C. Orbitofrontal Cortex K. Primary Somatosensory Cortex/ Postcentral Gyrus I. Primary Gustatory Cortex J. Somatosensory Association Cortex G. Primary Visual Cortex H. Visual Association Area E. Primary Auditory Cortex F. Wernike’s Area D. Primary Olfactory Cortex (Deep) http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
    28. 34. A: Primary Motor Cortex * This graphic representation of the regions of the Primary Motor Cortex and Primary Sensory Cortex is one example of a HOMUNCULUS: Homunculus
    29. 49. Q: Assuming this comical situation was factually accurate, what Cortical Region of the brain would these doctors be stimulating? Copyright: Gary Larson
    30. 50. <ul><li>Ⅰ Olfactory nerve </li></ul><ul><li>Ⅱ Optic nerve </li></ul><ul><li>Ⅲ Oculomotor nerve </li></ul><ul><li>Ⅳ Trochlear nerve </li></ul><ul><li>Ⅴ Trigeminal nerve </li></ul><ul><li>Ⅵ Abducent nerve </li></ul><ul><li>Ⅶ Facial nerve </li></ul><ul><li>Ⅷ Vestibulocochlear nerve </li></ul><ul><li>Ⅸ Glossopharyngeal nerve </li></ul><ul><li>Ⅹ Vagus nerve </li></ul><ul><li>Ⅺ Accessory nerve </li></ul><ul><li>Ⅻ Hypoglossal nerve </li></ul>
    31. 51. <ul><li>Sensory cranial nerves : contain only afferent (sensory) fibers </li></ul><ul><ul><li>Ⅰ Olfactory nerve </li></ul></ul><ul><ul><li>Ⅱ Optic nerve </li></ul></ul><ul><ul><li>Ⅷ Vestibulocochlear nerve </li></ul></ul><ul><li>Motor cranial nerves : contain only efferent (motor) fibers </li></ul><ul><ul><li>Ⅲ Oculomotor nerve </li></ul></ul><ul><ul><li>Ⅳ Trochlear nerve </li></ul></ul><ul><ul><li>Ⅵ Abducent nerve </li></ul></ul><ul><ul><li>Ⅺ Accessory nerv </li></ul></ul><ul><ul><li>Ⅻ Hypoglossal nerve </li></ul></ul><ul><li>Mixed nerves : contain both sensory and motor fibers--- </li></ul><ul><ul><li>Ⅴ Trigeminal nerve, </li></ul></ul><ul><ul><li>Ⅶ Facial nerve, </li></ul></ul><ul><ul><li>Ⅸ Glossopharyngeal nerve </li></ul></ul><ul><ul><li>Ⅹ Vagus nerve </li></ul></ul>
    32. 52. N. Location of cell body and axon categories Cranial exit Terminal nuclei Main action Ⅰ Olfactory cells (SVA) Cribrifom foramina Olfactory bulb Smell Ⅱ Ganglion cells (SSA) Optic canal Lateral geniculate body Vision Ⅷ Vestibular ganglion(SSA) Internal acoustic meatus Vestibular nuclei Equilibrium Cochlear ganglion (SSA) Cochlear nuclei Hearing
    33. 53. <ul><li>Olfactory mucosa (SVA) -> Cribriform foramina -> Olfactory bulb </li></ul>
    34. 54. <ul><li>Ganglion cell (SSA) -> Optic canal -> Lateral geniculate body </li></ul>
    35. 55. <ul><li>Vestibular ganglion(SSA) ↘ ↗ Vestibular nuclei </li></ul><ul><li>Internal acoustic meatus </li></ul><ul><li>Cochlear ganglion (SSA) ↗ ↘ Cochlear nuclei </li></ul>
    36. 56. N. Nucleus of origin and axon categories Cranial exit Main action Ⅲ Nucleus of oculomotor (GSE) Superior orbital fissure Motot to superior, inferior and medial recti; inferior obliquus; levator palpebrae superioris Accessory nucleus of oculomotor (GVE) Parasympathetic to sphincter pupillea and ciliary muscl Ⅳ Nucleus of trochlear nerve (GSE) Superior orbital fissure Motor to superior obliquus Ⅵ Nucleus of abducent nerve (GSE) Superior orbital fissure Motor to lateral rectus Ⅺ Nucleus of accessory nerve (SVE) Jugular foramen Motor to sternocleidomastoid and trapezius Ⅻ Nucleus of hypoglossal nerve( GSE) Hypoglossal canal Motot to muscles of tongue
    37. 58. <ul><li>Components </li></ul><ul><ul><li>General somatic efferent fibers (GSE) </li></ul></ul><ul><ul><li>General visceral efferent fibers (GVE) </li></ul></ul><ul><li>Main action - supplies </li></ul><ul><ul><li>Superior, inferior and medial recti; inferior obliquus; levator palpebrae superioris </li></ul></ul><ul><ul><li>Sphincter pupillea and ciliary muscle </li></ul></ul><ul><li>Ciliary ganglion: lies between optic nerve and lateral rectus </li></ul>Oculomotor nerve
    38. 59. Accessory nerve Abducent nerve
    39. 60. Hypoglossal nerve
    40. 61. Oculamotor paralysis Abducent nerve injury
    41. 63. <ul><li>Components of fibers </li></ul><ul><li>SVE fibers : originate from motor nucleus of trigeminal nerve, and supply masticatory muscles </li></ul><ul><li>GSA fibers : transmit facial sensation to sensory nuclei of trigeminal nerve, the GSA fibers have their cell bodies in trigeminal ganglion, which lies on the apex of petrous part of temporal bone </li></ul>
    42. 65. <ul><li>Branches </li></ul><ul><li>Ophthalmic nerve (Ⅴ1, sensory) leave the skull through the superior orbital fissure, to enter orbital cavity </li></ul><ul><li>Branches </li></ul><ul><ul><li>Frontal nerve: </li></ul></ul><ul><ul><ul><li>Supratrochlear nerve </li></ul></ul></ul><ul><ul><ul><li>Supraorbital nerve </li></ul></ul></ul><ul><ul><ul><li>Lacrimal nerve </li></ul></ul></ul><ul><ul><ul><li>Nasociliary nerve </li></ul></ul></ul>
    43. 66. <ul><li>Distribution: </li></ul><ul><li>Sensation from cerebral dura mater </li></ul><ul><li>Visual organ </li></ul><ul><li>Mucosa of nose </li></ul><ul><li>Skin above the eye and back of nose </li></ul>
    44. 67. <ul><li>Maxillary nerve (Ⅴ2, sensory) </li></ul><ul><li>Leave skull through foramen rotundum </li></ul><ul><li>Branches </li></ul><ul><ul><li>Infraorbital nerve </li></ul></ul><ul><ul><li>Zygomatic nerve 颧 </li></ul></ul><ul><ul><li>Superior alveolar nerve </li></ul></ul><ul><ul><li>Pterygopalatine nerve </li></ul></ul>
    45. 68. <ul><li>Distribution : </li></ul><ul><li>Sensation from cerebral dura mater </li></ul><ul><li>Maxillary teeth </li></ul><ul><li>Mucosa of nose and mouth </li></ul><ul><li>Skin between eye and mouth </li></ul>
    46. 69. <ul><li>Mandibular nerve (Ⅴ3, mixed) </li></ul><ul><li>Leave the skull through the foramen ovale to enter the infratemporal fossa </li></ul><ul><li>Branches </li></ul><ul><ul><li>Auriculotemporal nerve 耳颞 </li></ul></ul><ul><ul><li>Buccal nerve </li></ul></ul><ul><ul><li>Lingual nerve </li></ul></ul><ul><ul><li>Inferior alveolar nerve </li></ul></ul><ul><ul><li>Nerve of masticatory muscles </li></ul></ul>
    47. 71. <ul><li>Distribution : </li></ul><ul><li>Sensation from cerebral dura mater </li></ul><ul><li>Teeth and gum of lower jaw </li></ul><ul><li>Mucosa of floor of mouth </li></ul><ul><li>Anterior 2/3 of tongue </li></ul><ul><li>Skin of auricular and temporal regions and below the mouth </li></ul><ul><li>Motor to masticatory muscles, mylohyoid, and anterior belly of digastric </li></ul>
    48. 72. <ul><li>Components of fibers </li></ul><ul><li>SVE fibers originate from nucleus of facial nerve, and supply facial muscles </li></ul><ul><li>GVE fibers derived from superior salivatory nucleus and relayed in pterygopalatine ganglion and submandibular ganglion. The postganglionic fibers supply lacrimal, submandibular and sublingual glands </li></ul><ul><li>SVA fiber from taste buds of anterior two-thirds of tongue which cell bodies are in the geniculate ganglion of the facial nerve and end by synapsing with cells of nucleus of solitary tract </li></ul><ul><li>GSA fibers from skin of external ear </li></ul>
    49. 74. <ul><li>Course : leaves skull through internal acoustic meatus, facial canal and stylomastoid foramen, it then enters parotid gland where it divides into five branches which supply facial muscles </li></ul>
    50. 75. <ul><li>Branches within the facial canal </li></ul><ul><li>Chorda tympani : joins lingual branch of mandibular nerve </li></ul><ul><ul><li>To taste buds on anterior two-thirds of tongue </li></ul></ul><ul><ul><li>Relayed in submandibular ganglion, the postganglionic fibers supply submandibular and sublingual glands </li></ul></ul>
    51. 76. <ul><li>Greater petrosal nerve : GVE fibers pass to pterygopalatine ganglion 翼腭神经节 and there relayed through the zygomatic and lacrimal nerves to lacrimal gland </li></ul><ul><li>Stapedial nerve : to stapedius </li></ul>
    52. 77. <ul><li>Branches outside of facial canal </li></ul><ul><li>Temporal </li></ul><ul><li>Zygomatic </li></ul><ul><li>Buccal </li></ul><ul><li>Marginal mandibular </li></ul><ul><li>Cervical </li></ul>
    53. 78. <ul><li>Pterygopalatine ganglion : lies in pterygopalatine fossa under maxillary nerve </li></ul><ul><li>Submandibular ganglion : lies between lingual nerve and submandibular gland </li></ul>
    54. 79. Injury to the facial nerve
    55. 80. <ul><li>Components of fibers </li></ul><ul><li>SVE fibers: originate from nucleus ambiguus, and supply stylopharygeus </li></ul><ul><li>GVE fibers: arise from inferior salivatory nucleus and ralyed in otic ganglion, the postganglionic fibers supply parotid gland </li></ul><ul><li>SVA fibers: arise from the cells of inferior ganglion, the central processes of these cells terminate in nucleus of solitary tract, the peripheral processes supply the taste buds on posterior third of tongue </li></ul><ul><li>GVA fibers: visceral sensation from mucosa of posterior third of tongue, pharynx, auditory tube and tympanic cavity, carotid sinus and glomus, and end by synapsing with cells of nucleus of solitary tract </li></ul><ul><li>GSA fibers: sensation from skin of posterior surface of auricle and </li></ul>
    56. 82. <ul><li>Course : leaves the skull via jugular foramen </li></ul><ul><li>Branches </li></ul><ul><li>Lingual branches : to taste buds and mucosa of posterior third of tongue </li></ul><ul><li>Pharyngeal branches : take part in forming the pharyngeal plexus </li></ul><ul><li>Tympanic nerve : GVE fibers via tympanic and lesser petrosal nerves to otic ganglion, with postganglionic fibers via auriculotemporal (Ⅴ3) to parotid gland </li></ul><ul><li>Carotid sinus branch : innervations to both carotid sinus and glomus </li></ul><ul><li>Others: tonsillar and stylophayngeal branches </li></ul><ul><li>Otic ganglion : situated just below foramen ovale </li></ul>
    57. 84. <ul><li>components of fibers </li></ul><ul><li>GVE fibers: originate from dorsal nucleus of vagus nerve, synapse in parasympathetic ganglion, short postganglionic fibers innervate cardiac muscles, smooth muscles and glands of viscera </li></ul><ul><li>SVE fibers: originate from ambiguus, to muscles of pharynx and larynx </li></ul><ul><li>GVA fibers: carry impulse from viscera in neck, thoracic and abdominal cavity to nucleus of solitary tract </li></ul><ul><li>GSA fiber: sensation from auricle, external acoustic meatus and cerebral dura mater </li></ul>
    58. 86. <ul><li>Course </li></ul><ul><li>Exits the skull from jugular foramen </li></ul><ul><li>Descends in the neck in carotid sheath between internal (or common) carotid artery and internal jugular vein </li></ul><ul><li>Right vagus nerve </li></ul><ul><li>Enter thoracic inlet on right side of trachea </li></ul><ul><li>Travels downward posterior to right brachiocephalic vein and superior vena cava </li></ul><ul><li>Passes posterior to right lung root </li></ul><ul><li>Forms posterior esophageal plexus </li></ul><ul><li>Forms posterior vagal trunk at esophageal hiatus where it leaves thorax and passes into abdominal cavity, then divides into posterior gastric and celiac branches </li></ul>
    59. 87. <ul><li>Left vagus nerve </li></ul><ul><li>Enter thoracic inlet between left common carotid and left subclavian arteries, posterior to left brachiocephalic vein </li></ul><ul><li>Crosses aortic arch where left recurrent laryngeal nerve branches off </li></ul><ul><li>Passes posterior to left lung root </li></ul><ul><li>Forms anterior esophageal plexus </li></ul><ul><li>Forms anterior vagal trunk at esophageal hiatus where it leaves thorax and passes into abdominal cavity , then divides into anterior gastric and hepatic branches </li></ul>
    60. 88. <ul><li>Branches in neck </li></ul><ul><li>Superior laryngeal nerve : passes down side of pharynx and given rise to </li></ul><ul><ul><li>Internal branch , which pierces thyrohyoid membrane to innervates mucous membrane of larynx above fissure of glottis </li></ul></ul><ul><ul><li>External branch , which innervates cricothyroid </li></ul></ul><ul><li>Cervical cardiac branches : descending to terminate in cardiac plexus </li></ul><ul><li>Others: auricular, pharyngeal and meningeal branches </li></ul>
    61. 89. Superior laryngeal nerve External branch Internal branch
    62. 90. <ul><li>Branches in thorax </li></ul><ul><li>Recurrent laryngeal nerves </li></ul><ul><ul><li>Right one hooks around right subclavian artery, left one hooks aortic arch </li></ul></ul><ul><ul><li>Both ascend in tracheo-esophageal groove </li></ul></ul><ul><ul><li>Nerves enter larynx posterior to cricothyroid joint, the nerve is now called inferior laryngeal nerve </li></ul></ul><ul><ul><li>Innervations: laryngeal mucosa below fissure of glottis , all laryngeal laryngeal muscles except cricothyroid </li></ul></ul><ul><li>Bronchial and esophageal branches </li></ul>
    63. 91. <ul><li>Branches in abdomen </li></ul><ul><li>Anterior and posterior gastric branches </li></ul><ul><ul><li>Run close to lesser curvature and innervate anterior and posterior surfaces of stomach </li></ul></ul><ul><ul><li>As far as pyloric antrum to fan out into branches in a way like the digits of a crow’s foot to supply pyloric part </li></ul></ul><ul><li>Hepatic branches : join hepatic plexus and then supply liver and gallbladder </li></ul><ul><li>Celiac branches : send branches to celiac plexus to be distributed with sympathetic fibers to liver, pancreas, spleen, kidneys, intestine as far as left colic flexure </li></ul>
    64. 99. &quot; Men ought to know that from nothing else but the brain come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations. Hippocrates ( 460 BC – ca. 370 BC)

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