Each of the twelve chapters that follow is devoted to indepth coverage of a different cranial nerve. The optic nerve begins at the optic disk, a structure that is 1. Each ganglion is oval in shape, reddish in color, and its size bears a proportion to that of the nerve root on which it is situated. Presentation layout embryology of optic nerve introduction parts of optic nerve blood supply clinical significance 3.
Pdf the facial nerve anatomy and clinical implications. The optic nerve leaves the orbit via the optic canal, which runs posteromedially towards the optic chiasm, where there is a partial decussation crossing of fibers from the temporal visual fields the nasal hemiretina of both eyes. Ct provides high spatial resolution for evaluation of osseous details, including fractures, bony destruction, and periosteal reaction. It consists of 15 vector anatomical drawings with 280 anatomical structures labeled. Learn anatomy test 2 nerve with free interactive flashcards. Peripheral nerve anatomy university of california, irvine. I liked how it had a different color for each modality general sensory afferent, branchial motor, etc. Nerve structure anatomy nerves are the organs that make up the peripheral nervous system pns. Lecture covering the anatomy and physiology of the optic nerve.
Moreover, part of the spinal accessory nerve arises from the cervical spinal cord. Peripheral nerves, anatomy and physiology of springerlink. An intimate knowledge of facial nerve anatomy is critical to avoid its inadvertent injury during rhytidectomy, parotidectomy, maxillofacial fracture reduction, and almost any surgery of the head and neck. Start studying anatomy cranial nerves with pictures. In the peripheral nervous system, bundles of nerve. As a consequence, the fibers are covered with myelin produced by. The main sensory and motor nuclei of the cranial nerves are shown in fig. It carries sensory fibers from the heart, lower respiratory tract, and gastrointestinal tract as far distal as the transverse colon ellis, 2006, hansen, 2010, patestas and gartner, 2006.
The autonomic nervous system is the part of the nervous system concerned with the innervation of involuntary structures, such as the heart, smooth muscle, and glands within the body. It maps out each cranial nerve, explains its course, functions, etc. It is the second of several pairs of cranial nerves. Table of contents introduction surface marking functional components nuclei course and relations branches and distribution. Vestibulocochlear viii nerve anatomy carries two groups of fibres, those to the cochlea hearing and to the semicircular canals, utricle and saccule balance and posture. Botte, md, san diego, ca knowledge of radial nerve motor branch anatomy is important when performing surgery in. Cliffsnotes study guides are written by real teachers and professors, so no matter what youre studying, cliffsnotes can ease your homework headaches and help you score high on exams. The optic nerve begins at the optic disk, optic nerve, second cranial nerve, which carries sensory nerve impulses from the more than one million ganglion cells of the retina toward the visual centres in the brain. The optic nerve, also known as cranial nerve ii, or simply as cn ii, is a paired cranial nerve that transmits visual information from the retina to the brain. The sensory neurons in the olfactory epithelium are outside the meninges and below the cribriform plate. The afferent nerve happens to be the optic nerve, which carries the stimulus to the optic tract but past the lgn no synapse there to the edingerwestphal nuclei the rostral third of the oculomotor nucleus in the midbrain. Radiationinduced optic neuropathy can involve any part of the optic nerve, including the optic nerve head fig.
They pass, together with the facial nerve, from the brainstem across the posterior fossa to the internal acoustic meatus. Peripheral nerves are formed by axonal extensions of neurons in the dorsal root ganglia and spinal cord spinal nerves, brain stem cranial nerves, or sympathetic and parasympathetic ganglia autonomic nerves that connect the central nervous system brain and spinal cord with the rest of the body to maintain homeostasis, mediate sensation, movement. It is intended for the use of medical students working on human anatomy, student nurses, physiotherapists, electroradiological technicians and residents especially those working in neurology, neurosurgery. There are approximately one million axons in the optic nerve, constituting almost 40% of the total number of axons in all cranial nerves. The primary sensors for sight are the million rods and seven million cones found in the retina. The optic nerve head also known as the optic disc is approximately 1. Develops from the neuroectodermal cells forming the outer wall of the optic stalk. Clinical anatomy of the cranial nerves 1st edition. Known to the greek fathers of anatomy as nervus optikus, the optic nerve has the responsibility of transmitting special afferent impulses of light to the brain. The optic nerve functions to transmit sensory information to the brain for further processing. Within the nerve, microvasculature runs along the outer layer epineurium with a transverse capillary network perfusing the endoneureum. It is also called the second cranial nerve or cranial nerve ii. The key points of the on are the optic nerve head and chiasm. One common example of nerve pain occurs when a person has a lumbar herniated disc.
Anatomy and physiology of peripheral nerve injury and repair. The structure indicated is the optic nerve cranial nerve ii the optic nerve is the second cranial nerve and is responsible for vision. Treatment of ong is customized to the individual patient and may include observation, surgery, radiation therapy, and chemotherapy e. Structure and function 9 this layer is constituted by axonal bundles that are formed by the gathering of rows of axons that converge on their w ay to the optic disc. Similar to the first cranial nerve olfactory nerve, the optic nerve is not a true nerve but is rather an extension of the brain diencephalon, which means it is technically a part of the central, rather than peripheral nervous system. Large nerve roots that go to the legs and arms are irritated.
Cranial nerves are involved in head and neck function, and processes such as eating, speech and facial expression. They serve as information pipelines that allow the brain and spinal cord to communicate with other tissues and organs. All the nerves are distributed in the head and neck except the tenth, which also supplies structures in the thorax and abdomen. Visual pathway government medical college and hospital. This is because embryologically, it is derived from an outpouching of the diencephalon. Anatomy and physiology of the optic nerve eccles health. In humans, the optic nerve is derived from optic stalks during the seventh week of development and is composed of retinal ganglion cell axons and glial cells. The vagus nerve is the most extensively distributed cranial nerve in the body figure 27. Optic nerve anatomy the optic nerve is a sensory nerve. Differentiates into astrocytes and oligodendrocyte. It is also involved in several reflex arcs related to the ocular system.
They synapse in the bulb itself, and those secondary neurons project. Supranuclear lesions can be evaluated with standard. Its basic responsibility is to transmit information received from rods and cones in the eye known as photoreceptors, and then deliver this information that is received from the retina. With the release of glutamate, they transform electromagnetic waves. A peripheral nerve trunk such as the radial or medial nerve of the arm are comprised of axons of multiple neurons bundled in connective tissue fascicles surrounded by perineurium. Optometry, maharajgunj medical campus, institute of medicine,t.
This human anatomy module is about the cranial nerves. Optic nerve is considered a part of central nervous system instead of the peripheral nervous system. The anatomy and physiology of peripheral nerve injury is vital information for the treating surgeon. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The management of peripheral nerve injury continues to be a major clinical challenge. Their central processes synapse on ganglion cells on the vitreous surface of the retina and their central processes pass via the.
All of the pertinent anatomical topics are conveniently organized to instruct on anatomy, but also on how to examine the functioning of this anatomy. Damage to the optic nerve can occur after radiotherapy of sellar and parasellar tumors and of lymphoproliferative and leukemic disease of the orbit. Choose from 500 different sets of anatomy test 2 nerve flashcards on quizlet. Clinical anatomy of the cranial nerves combines anatomical knowledge, pathology, clinical examination, and explanation of clinical findings, drawing together material typically scattered throughout anatomical textbooks.
Anatomy of the optic nerve and visual pathway sciencedirect. Imaging anatomy of the cranial nerves ch apter 14 183 neuralgia is thought to be caused by vascular compression on the fifth cranial nerve by a cerebellar artery. Several slides show microscopic images of optic nerve damage. The accurate and finely detailed surgical anatomy of peripheral nerves is difficult to find in any one textbook or resource. Anatomy of the radial nerve motor branches in the forearm. Optic nerve glioma ong is the most common intrinsic optic nerve tumor in children, and optic nerve sheath meningioma is the most common one in adults. Direct patient to read aloud line wsmallest lettering that theyre able to see.
Illustrations and diagrams of the 12 pairs of cranial nerves. Anatomy of facial nerveanatomy of facial nerve presented by dr. At the back of the eyeball, there is a gathering place for the optic nerves, and here, approximately 125 million nerve fibers which make up the. Smaller nerves that innervate the spine are irritated. Cranial nerve anatomy by greg mclauchlin i olfactory nerve the olfactory nerve is unique, but not in ways that make it particularly interesting. The optic nerve is the second cranial nerve which, along with the olfactory nerve cn i, is really an extension of the central nervous system. It is not surrounded by schwann cells with the first sensory bipolar cell body located peripherally in the retina. The identity of cranial nerve ii cn ii, also known as the optic nerve, predates galenic anatomy. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Intra ocular part intraocular part passes through sclera converting it into a sievelike structurethe lamina cribrosa, choroid and finally appears inside the eye as optic disc. The dimensions of the cup and disc are dependent on the orientation, shape and size of the chorioscleral canal that exists at bruchs membrane. An introductory chapter provides a brief overview of cranial nerve anatomy and function, skull base anatomy, classification of pathologies, and imaging approaches. Monkhouse, 2006, nolte and sundsten, 2009, patestas and gartner, 2006. Knowledge of the normal anatomy, embryology, and spectrum of abnormality will aid radiologists in correctly diagnosing lesions of the facial nerve.
Anatomy of the radial nerve motor branches in the forearm reid a. The optic disk forms from the convergence of ganglion cell output fibres called axons as they pass out of the eye. The spinal ganglia ganglion spinale are collections of nerve cells on the posterior roots of the spinal nerves. The optic nerve on is constituted by the axons of the retinal ganglion cells rgcs. Anatomy and pathology of the facial nerve imaging approaches ct and mri have complementary roles in evaluation of the facial nerve. These axons are distributed in an organized pattern from the soma of the rgc to the lateral geniculated nucleus where most of the neurons synapse. Pure sensory nerve it is a spare part and does not supply the gastrocs like the sural a.
542 339 1126 364 979 1106 178 194 368 1021 1358 674 955 983 440 1012 1493 325 965 1218 775 476 777 1160 94 54 195 193 1235 1048 1255 637 680