DOCSLIB.ORG

Anatomy of the Extraneural Blood Supply to the Intracranial

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Anatomy of the Extraneural Blood Supply to the Intracranial British Journal of Ophthalmology 1996; 80: 177-181 177 the extraneural blood to the Anatomy of supply Br J Ophthalmol: first published as 10.1136/bjo.80.2.177 on 1 February 1996. Downloaded from intracranial oculomotor nerve Mark Cahill, John Bannigan, Peter Eustace Abstract have since been classified as extraneural vessels Aims-An anatomical study was under- as they arise from outside the nerve and ramify taken to determine the extraneural blood on the surface ofthe nerve. In 1965, Parkinson supply to the intracranial oculomotor attempted to demonstrate and name the nerve. branches of the intracavernous internal carotid Methods-Human tissue blocks contain- artery.3 One of these branches, the newly titled ing brainstem, cranial nerves II-VI, body meningohypophyseal trunk was seen to pro- of sphenoid, and associated cavernous vide a nutrient arteriole to the oculomotor sinuses were obtained, injected with con- nerve in the majority of dissections. The infe- trast material, and dissected using a rior hypophyseal artery was also seen to arise stereoscopic microscope. from the meningohypophyseal trunk. Seven Results-Eleven oculomotor nerves were years earlier McConnell had demonstrated dissected, the intracranial part being that this vessel provided a large portion of the divided into proximal, middle, and distal pituitary blood supply.4 (intracavernous) parts. The proximal part Asbury and colleagues provided further of the intracranial oculomotor nerve anatomical detail in 1970.5 They set out to received extraneural nutrient arterioles explain the clinical findings of diabetic oph- from thalamoperforating arteries in all thalmoplegia on a pathological basis. Using a specimens and in six nerves this blood serial section technique, they demonstrated an supply was supplemented by branches intraneural network of small arterioles within from other brainstem vessels. Four nerves the oculomotor nerve. By this technique it was were seen to be penetrated by branches of also determined that the extraneural arterioles brainstem vessels and these penetrating to the oculomotor nerve arose proximally from arteries also supplied nutrient arterioles. a variety ofbrainstem arteries and distally from The middle part ofthe intracranial oculo- non-specific branches of the inferior cavernous motor nerve did not receive nutrient arte- sinus artery. More recently, three studies have rioles from adjacent arteries. The distal set out to demonstrate the anatomy of the part of the intracranial oculomotor nerve extraneural blood supply to the proximal part http://bjo.bmj.com/ received nutrient arterioles from the infe- (also termed the interpeduncular or cisternal rior cavernous sinus artery in all 11 nerves part) of the intracranial oculomotor nerve.6-8 and in seven nerves this was supple- Two ofthese studies by Milisavljevic et al,8 and mented by a tentorial artery arising from Marinkovic and Gibo,7 noted that the proxi- the meningohypophyseal trunk. The infe- mal intracranial oculomotor nerve can be pen- rior hypophyseal artery arose from the etrated by branches of brainstem arteries. meningohypophyseal trunk in all 11 cav- These penetrating arteries can also supply on September 27, 2021 by guest. Protected copyright. ernous sinuses dissected. nutrient arterioles to the nerves they penetrate. Conclusion-This study shows a constant The present anatomical study was under- pattern to the blood supply of the taken to demonstrate the extraneural blood intracranial oculomotor nerve. It also supply to the intracranial oculomotor nerve. highlights the close relation between the We wanted to clarify the anatomical details Institute of blood supplies to the intracavernous ocu- using information from earlier studiesl-8 1012 Ophthalmology, University College lomotor nerve and the pituitary gland. and our own dissection findings (Fig 1). We Dublin, Mater (Br_' Ophthalmol 1996; 80: 177-181) also examined the relation between the blood Misericordiae supply to the intracavernous section of the Hospital, Dublin, Ireland oculomotor nerve and that to the pituitary M Cahill Up to now no definitive detailed study of the gland. P Eustace blood supply to the intracranial portion of the Department of third cranial nerve has been published. It is this Anatomy, The Medical portion of the third cranial nerve that has par- Materials and methods School, University ticular importance in neuro-ophthalmology. Six tissue blocks containing midbrain, pons, College Dublin, Dublin, Ireland Bartholdy, in 1897, first described that cranial cerebellum, cranial nerves II-VI, basilar artery M Cahill nerves received nutrient vessels from adjacent (and branches), body of sphenoid with associ- J Bannigan arteries.' However, technical difficulties pre- ated pituitary gland, and cavernous sinuses Correspondence to: vented any definite anatomical patterns being were removed from postmortem subjects and Professor Peter Eustace, demonstrated. It was not until 1957 that immediately fixed in a solution of 1O% forma- Institute of Ophthalmology, University College Dublin, Dreyfus et al, in a paper dealing with diabetic lin. To facilitate identification of vessels sup- Mater Misericordiae ophthalmoplegia, demonstrated that arteries plying the intracranial oculomotor nerve and Hospital, 60 Eccles Street, Dublin 7, Ireland. from the basilar circulation and circle of Willis other structures, the basilar and internal Accepted for publication gave off nutrient arterioles to the intracranial carotid arteries were injected with India ink 1 1 October 1995 part of the oculomotor nerve.2 These vessels before dissection. The specimens were dis- 178 CahiUl, Bannigan, Eustace Midbrain and a long circumflex artery penetrated the remaining nerve. Br J Ophthalmol: first published as 10.1136/bjo.80.2.177 on 1 February 1996. Downloaded from Sh Circum A MIDDLE NERVE The middle part ofthe intracranial oculomotor nerve was not seen to receive nutrient arter- ioles along its length from adjacent arteries. DISTAL NERVE In seven of 11 cavernous sinuses examined, the oculomotor nerve and its surrounding ten- Figure1 The blood supply to a right intracranial oculomotor nerve seen from the right. PCA=posterior cerebral artery, S CerA=superior cerebellar artery, L Circum A=long torium was seen to receive nutrient arterioles circumflex artery, Sh Circum A=short circumflex artery, P Comm A=posterior from an anteriorly directed tentorial artery communicating artery, III CN=oculomotor nerve, ICA=internal carotid artery, which was a branch of the meningohypo- MHT= meningohypophyseal trunk, InfCav Sin A=inferior cavernous sinus artery. Dark outline represents the limits ofthe cavernous sinus. physeal trunk (Figs 3A and 3B). In all 11 cavernous sinuses examined, an attempt was made to identify four branches of the inferior sected with the aid of a stereoscopic micro- cavernous sinus artery - an anterior branch, a scope. Photographs were taken and drawings tentorial branch, a descending branch, and were made at all stages of the dissections. a posterior branch (Figs 4A and 4B). All 11 distal oculomotor nerves received nutrient arterioles from branches of the inferior Results cavernous sinus artery. In four nerves these Our of 12 possible intracranial oculomotor nutrient arterioles arose from the anterior nerves, 11 were dissected. For simplicity the branch, in five they arose from the tentorial intracranial oculomotor nerve was anatomi- branch and in two nerves both the anterior cally divided into three parts. The proximal branch and the tentorial branch supplied part consisted of the part from the emergence nutrient vessels to the oculomotor nerve. ofthe nerve at the cerebral peduncles to a point In all 11 of the cavernous sinuses dissected just distal to the anastomosis of the posterior the inferior hypophyseal artery was seen to cerebral and posterior communicating arteries. arise from the meningohypophyseal trunk The middle part was that part from the latter (Figs 3A and 3B). The ophthalmic artery did point to just before the oculomotor nerve not supply nutrient arterioles to the oculo- enters the cavernous sinus. The distal part was motor nerve in any of the 11 cavernous sinuses that part of the nerve within the cavernous dissected. sinus. http://bjo.bmj.com/ Discussion PROXIMAL NERVE To date, no study has attempted systematically In all specimens, the proximal parts ofthe ocu- to identify and name the extraneural blood lomotor nerve were supplied by thalamoperfo- supply to the intracranial oculomotor nerve. rating arteries arising from the posterior The term extraneural is used to encompass cerebral artery (Figs 2A and 2B). In five oculo- those small arterioles arising from larger on September 27, 2021 by guest. Protected copyright. motor nerves these were the only extraneural arteries adjacent to the oculomotor nerve. nutrient vessels to the proximal nerve. In the These are distinct from the intraneural arteri- remaining six nerves these were supplemented oles which form a plexus of capillaries within by a number of brainstem arteries, outlined in the nerve substance. We felt that the clearest Table 1. The proximal part of the intracranial way to demonstrate the anatomy of the extra- oculomotor nerve was seen to be penetrated by neural blood supply to the oculomotor nerve arteries in four nerves, which also supplied would be to divide it into three. Those seg- nutrient vessels to the nerve. In two nerves the ments ofthe nerve that make up these divisions penetrating artery was the long circumflex (proximal, middle, and distal) have
Load more

Recommended publications
  • Congenital Oculomotor Palsy: Associated Neurological and Ophthalmological Findings
    CONGENITAL OCULOMOTOR PALSY: ASSOCIATED NEUROLOGICAL AND OPHTHALMOLOGICAL FINDINGS M. D. TSALOUMAS1 and H. E. WILLSHA W2 Birmingham SUMMARY In our group of patients we found a high incidence Congenital fourth and sixth nerve palsies are rarely of neurological abnormalities, in some cases asso­ associated with other evidence of neurological ahnor­ ciated with abnormal findings on CT scanning. mality, but there have been conflicting reports in the Aberrant regeneration, preferential fixation with literature on the associations of congenital third nerve the paretic eye, amblyopia of the non-involved eye palsy. In order to clarify the situation we report a series and asymmetric nystagmus have all been reported as 1 3 7 of 14 consecutive cases presenting to a paediatric associated ophthalmic findings. - , -9 However, we tertiary referral service over the last 12 years. In this describe for the first time a phenomenon of digital lid series of children, 5 had associated neurological elevation to allow fixation with the affected eye. Two abnormalities, lending support to the view that con­ children demonstrated this phenomenon and in each genital third nerve palsy is commonly a manifestation of case the accompanying neurological defect was widespread neurological damage. We also describe for profound. the first time a phenomenon of digital lid elevation to allow fixation with the affected eye. Two children demonstrated this phenomenon and in each case the PATIENTS AND METHODS accompanying neurological defect was profound. The Fourteen children (8 boys, 6 girls) with a diagnosis of frequency and severity of associated deficits is analysed, congenital oculomotor palsy presented to our paed­ and the mechanism of fixation with the affected eye is iatric tertiary referral centre over the 12 years from discussed.
    [Show full text]
  • Clinical Anatomy of the Cranial Nerves Clinical Anatomy of the Cranial Nerves
    Clinical Anatomy of the Cranial Nerves Clinical Anatomy of the Cranial Nerves Paul Rea AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic Press is an imprint of Elsevier Academic Press is an imprint of Elsevier 32 Jamestown Road, London NW1 7BY, UK The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK Radarweg 29, PO Box 211, 1000 AE Amsterdam, The Netherlands 225 Wyman Street, Waltham, MA 02451, USA 525 B Street, Suite 1800, San Diego, CA 92101-4495, USA First published 2014 Copyright r 2014 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangement with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.
    [Show full text]
  • Cranial Nerves
    Cranial Nerves Cranial nerve evaluation is an important part of a neurologic exam. There are some differences in the assessment of cranial nerves with different species, but the general principles are the same. You should know the names and basic functions of the 12 pairs of cranial nerves. This PowerPage reviews the cranial nerves and basic brain anatomy which may be seen on the VTNE. The 12 Cranial Nerves: CN I – Olfactory Nerve • Mediates the sense of smell, observed when the pet sniffs around its environment CN II – Optic Nerve Carries visual signals from retina to occipital lobe of brain, observed as the pet tracks an object with its eyes. It also causes pupil constriction. The Menace response is the waving of the hand at the dog’s eye to see if it blinks (this nerve provides the vision; the blink is due to cranial nerve VII) CN III – Oculomotor Nerve • Provides motor to most of the extraocular muscles (dorsal, ventral, and medial rectus) and for pupil constriction o Observing pupillary constriction in PLR CN IV – Trochlear Nerve • Provides motor function to the dorsal oblique extraocular muscle and rolls globe medially © 2018 VetTechPrep.com • All rights reserved. 1 Cranial Nerves CN V – Trigeminal Nerve – Maxillary, Mandibular, and Ophthalmic Branches • Provides motor to muscles of mastication (chewing muscles) and sensory to eyelids, cornea, tongue, nasal mucosa and mouth. CN VI- Abducens Nerve • Provides motor function to the lateral rectus extraocular muscle and retractor bulbi • Examined by touching the globe and observing for retraction (also tests V for sensory) Responsible for physiologic nystagmus when turning head (also involves III, IV, and VIII) CN VII – Facial Nerve • Provides motor to muscles of facial expression (eyelids, ears, lips) and sensory to medial pinna (ear flap).
    [Show full text]
  • What Causes Microvascular Cranial Nerve Palsy? It Is Not Always Clear What Causes the Blockage in the Tiny Blood Vessels to the Cranial Nerves
    MICROVASCULAR CRANIAL NERVE PALSEY Microvascular Cranial Nerve Palsy (MCNP) is one of the most common causes of acute double vision in the older population. It occurs more often in patients with diabetes and high blood pressure. MCNP is sometimes referred to as a “diabetic” palsy. This condition almost always resolves on its own without leaving any double vision. Six muscles move your eyes. Four of these muscles attach to the front part of your eye (just behind the iris, or the colored portion of the eye). The two muscles that attach to the back of your eye are responsible for some of the up-and-down (vertical) movement and most of the twisting movement of each eye. These six muscles receive their signals from three cranial nerves that begin in the brain stem. What is Microvascular Cranial Nerve Palsy? A nerve cannot function properly when its blood flow is blocked. If the 6th cranial nerve (also called the abducens nerve) is affected, your eye will not be able to move to the outside and you will be aware of double vision, seeing side-by-side images. If the 4th cranial nerve (also called the trochlear nerve) is affected, you will be aware of vertical double vision (one image on top of another). You may be able to eliminate or decrease the double vision by tilting your head towards the opposite shoulder. The 3rd cranial nerve (also called the oculomotor nerve) supplies four of the six eye muscles. These are some of the muscles that control the eyelid and the size of the pupil.
    [Show full text]
  • Occurrence of Oculomotor Dysfunctions in Acquired Brain Injury: a Retrospective Analysis
    Optometry (2007) 78, 155-161 Occurrence of oculomotor dysfunctions in acquired brain injury: A retrospective analysis Kenneth J. Ciuffreda, O.D., Ph.D., Neera Kapoor, O.D., M.S., Daniella Rutner, O.D., M.S., Irwin B. Suchoff, O.D., D.O.S., M.E. Han, O.D., and Shoshana Craig, O.D. State University of New York State College of Optometry, Raymond J. Greenwald Rehabilitation Center, New York, New York. KEYWORDS Abstract Acquired brain injury; BACKGROUND: The purpose of this retrospective study was to determine the frequency of occurrence Traumatic brain of oculomotor dysfunctions in a sample of ambulatory outpatients who have acquired brain injury injury; (ABI), either traumatic brain injury (TBI) or cerebrovascular accident (CVA), with associated vision Cerebrovascular symptoms. accident; METHODS: Medical records of 220 individuals with either TBI (n ϭ 160) or CVA (n ϭ 60) were Stroke; reviewed retrospectively. This was determined by a computer-based query spanning the years 2000 Oculomotor through 2003, for the frequency of occurrence of oculomotor dysfunctions including accommodation, dysfunction; version, vergence, strabismus, and cranial nerve (CN) palsy. Strabismus; RESULTS: The majority of individuals with either TBI (90%) or CVA (86.7%) manifested an Accommodation; oculomotor dysfunction. Accommodative and vergence deficits were most common in the TBI Eye movements; subgroup, whereas strabismus and CN palsy were most common in the CVA subgroup. The frequency Cranial nerve palsy of occurrence of versional deficits was similar in each diagnostic subgroup. CONCLUSION: These new findings should alert the clinician to the higher frequency of occurrence of oculomotor dysfunctions in these populations and the associated therapeutic, rehabilitative, and quality-of-life implications.
    [Show full text]
  • A Study of Etiology and Prognosis of Oculomotor Nerve Paralysis
    Edorium J Neurol 2014;1:1–8. Kumar et al. 1 http://www.edoriumjournalofneurology.com ORIGINAL ARTICLE OPEN ACCESS A study of etiology and prognosis of oculomotor nerve paralysis Maraiah Pradeep Kumar, Undrakonda Vivekanand, Shashikiran Umakanth, Yashodhara BM ABSTRACT How to cite this article Aims: To study the etiological pattern and Kumar MP, Vivekanand U, Umakanth S, Yashodhara prognosis of oculomotor nerve palsy in a medical BM. A study of etiology and prognosis of oculomotor college hospital in South India. Methods: This nerve paralysis. Edorium J Neurol 2014;1:1–8. study comprises 40 cases of oculomotor nerve palsy presenting to medical college hospital between March 2004 to September 2005. Details Article ID: 100001N06MK2014 of various modes of presentation, aetiologies, pupillary involvement and recovery were documented and analysed. Conclusion: Isolated ********* oculomotor nerve palsy which is a predominant mode of presentation has a good recovery rate. doi:10.5348/n06-2014-1-OA-1 We recommend that patients with oculomotor nerve palsy be carefully examined clinically in close collaboration with other specialists, especially where sophisticated complementary investigations are impossible. INTRODUCTION Keywords: Oculomotor nerve palsy, Outcome, Etiological trends of oculomotor nerve palsy have Partial, Management remained fairly consistent over the decades, although there is a changing disease pattern worldwide and the current focus is on etiologies like diabetes, trauma and Maraiah Pradeep Kumar1, Undrakonda Vivekanand2, orbital inflammatory diseases which are emerging as 3 4 Shashikiran Umakanth , Yashodhara BM frequent causes of third cranial nerve paralysis [1, 2]. 1 Affiliations: Associate Professor, Department of Thus a collaborative approach with other specialties Ophthalmology, Shimoga Institute of Medical Sciences, Karnataka, India; 2Associate Professor, Department of is essential to enhance the diagnostic accuracy.
    [Show full text]
  • Acquired Palsy of the Oculomotor, Trochlear and Abducens Nerves
    ACQUIRED PALSY OF THE OCULOMOTOR, TROCHLEAR AND ABDUCENS NERVES l 2 P. A. C. TIFFIN\ C. J. MacEWEN\ E. A. CRAIG and G. CLAYTON Dundee SUMMARY commonly than trochlear nerve palsy. In addition, There have been few studies primarily concerned with although the major cause of ocular palsy was the relative frequencies, aetiologies and prognoses of consistently classified as undetermined (25%), a ocular motor palsies. Those published have emanated relatively high proportion of cases were recorded as largely from neurological tertiary referral centres rather secondary to sinister pathology: neoplasia (18%) and than primary ophthalmology departments. We have aneurysm (7%). performed a retrospective study of all patients with There have been several studies relating to series acquired III, IV or VI cranial nerve palsy who were of patients seen in the more general setting of both s 9 seen in the orthoptic department at Ninewells Hospital, orthoptic and ophthalmic clinics. - However, these Dundee, over the 9 year period from 1984 to 1992. A have concentrated on groups of patients presenting total of 165 cases were identified. VI nerve palsies with the somewhat broader diagnosis of diplopia accounted for the majority of patients (57%), with IV rather than only those with acquired nerve palsies nerve palsies (21%) occurring more frequently than III per se. Acquired ocular motor nerve palsy accounted nerve palsies (17%) and multiple palsies (5%). Thirty­ for 40-60% of patients presenting with binocular five per cent of cases were of unknown aetiology and diplopia. Although abducens nerve palsy occurred 6 8 9 32% of vascular aetiology. The incidence of sinister most frequently in most of these reports, , , oculo­ s pathology - neoplasia (2%) and aneurysm (1%) - was motor nerve palsy was found most often in one and surprisingly low.
    [Show full text]
  • Unit 11 Cranial Nerves, Spinal Cord, and Reflexes
    1 BIOL 2210L Unit 11: Cranial Nerves, Spinal Cord, and Reflexes Authors: Terri Koontz and Anna Gilletly, CNM Biology Department Creative Commons Attribution-NonCommercial 4.0 International License Terms to Know for Unit 11 Cranial Nerves Meninges Additional Instructor Terms Olfactory nerve Epidural space Olfactory bulb Dura mater Olfactory tract Arachnoid mater Optic nerve Subarachnoid space Optic chiasma Pia mater Optic tract Oculomotor nerve Reflex arc Trochlear nerve Receptor Trigeminal nerve Sensory neuron Facial nerve Afferent pathway Vestibulocochlear nerve Integration Center Glossopharyngeal nerve Interneuron Vagus nerve Motor neuron Accessory nerve Effector Hypoglossal nerve Patellar reflex Spinal Cord Patellar ligament Conus medullaris Femoral nerve Cauda equina Quadriceps femoris Gray matter Hamstrings Posterior horn Anterior horn Central canal Dorsal root Dorsal root ganglion Ventral root Spinal nerves White matter Filum terminale Anterior median fissure Posterior median fissure Learning Objectives (modified from HAPS learning outcomes) 1. Structure & function of cranial nerves 2 a. List and identify the cranial nerves by name and number. b. Describe the specific functions of each of the cranial nerves and classify each as sensory, motor or mixed. c. Identify the foramina that the cranial nerves pass through within the skull. 2. Anatomy of the spinal cord a. Describe the gross anatomy of the spinal cord. b. Identify the anatomical features seen in a cross sectional view of the spinal cord c. Identify the dorsal root ganglia, dorsal and ventral roots, and spinal nerves. 3. Reflexes & their roles in nervous system function a. Define the term reflex. b. Describe reflex responses in terms of the major structural and functional components of a reflex arc.
    [Show full text]
  • Human Anatomy Lab - Examination of the Cranial Nerves
    Utah State University DigitalCommons@USU Undergraduate Honors Capstone Projects Honors Program 5-1993 Human Anatomy Lab - Examination of the Cranial Nerves Jeanne Falk Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/honors Part of the Nervous System Commons Recommended Citation Falk, Jeanne, "Human Anatomy Lab - Examination of the Cranial Nerves" (1993). Undergraduate Honors Capstone Projects. 296. https://digitalcommons.usu.edu/honors/296 This Thesis is brought to you for free and open access by the Honors Program at DigitalCommons@USU. It has been accepted for inclusion in Undergraduate Honors Capstone Projects by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. JEANNE FALK SENIOR PROJECT HUMANANATOMY LAB - EXAMINATIONOF THE CRANIALNERVES The peripheral nervous system consists of twelve pairs of cranial nerves, 31 pairs of spinal nerves, and the nerves of the autonomic nervous system. The cranial nerves are the nerves that leave the brain directly. These nerves control various actions and sensations such as sight, smell, .chewing, and swallowing, and will be the focus of this week's lab. Of the twelve pairs of cranial nerves, two pairs arise from the forebrain, ten pairs arise from the midbrain and brain stem, and all but the Vagus nerve innervates the structures in the head and neck. Each cranial nerve pair is designated with a Roman nwneral in reference to the order in which the nerves are positioned from the front to the back of the brain. The names given to the nerves indicate the structures innervated or the principle functions of the nerves.
    [Show full text]
  • Lab 3. Pons & Midbrain
    Lab 3. Pons & Midbrain Lesion Lessons Lesion 4.1 Anne T. Pasta i) Location ii) Signs/symptoms (Slice of Brain © 993 Univs. of Utah and Washington; E.C. Alvord, Jr., Univ. of Washington) iii) Cause: Lesion 4.2 Colin S. Terase i) Location ii) Signs/symptoms (Slice of Brain © 993 Univs. of Utah and Washington; M.Z. Jones, Michigan St. Univ.) iii) Cause: Medical Neuroscience 4– Pontine Level of the Facial Genu Locate and note the following: Basilar pons – massive ventral structure provides the most obvious change from previous med- ullary levels. Question classic • pontine gray - large nuclear groups in the basilar pons. Is the middle cerebellar peduncle composed – origin of the middle cerebellar peduncle of climbing or mossy • pontocerebellar axons - originate from pontine gray neurons and cross to form the fibers? middle cerebellar peduncle. • corticopontine axons- huge projection that terminates in the basilar pontine gray. • corticospinal tract axons – large bundles of axons surrounded by the basilar pontine gray. – course caudally to form the pyramids in the medulla. Pontine tegmentum • medial lemniscus - has now assumed a “horizontal” position and forms part of the border between the basilar pons and pontine tegmentum. Question classic • central tegmental tract - located just dorsally to the medial lemniscus. What sensory modali- – descends from the midbrain to the inferior olive. ties are carried by the • superior olivary nucleus - pale staining area lateral to the central tegmental tract. medial and lateral – gives rise to the efferent olivocochlear projection to the inner ear. lemnisci? • lateral lemniscus - lateral to the medial lemniscus. – composed of secondary auditory projections from the cochlear nuclei.
    [Show full text]
  • The 12 Cranial Nerves
    The 12 Cranial Nerves Nerve # Name Function 1st Olfactory Relays smell 2nd Optic Transmits visual information 3rd Oculomotor External muscles of the eye 4th Trochlear Also supplies muscles of the eye 5th Trigeminal Chewing and sensation in the face 6th Abducent Controls lateral eye movement 7th Facial Muscles of facial expression, taste buds, sensation in fingers and toes, blinking 8th Auditory Hearing and balance 9th Glossopharyngeal Sensation, taste and swallowing 10th Vagus Organs in chest and abdomen 11th Accessory Supplies two neck muscles, the sternomastoid and trapezius 12th Hypoglossal Muscles of the tongue and neck The 12 Cranial Nerves—Detail Cranial Nerve 1 Sensory nerve – Olfactory Nerve – controls sense of smell Cranial Nerve 2 Sensory nerve- Optic Nerve- controls vision by sending information from retina Cranial Nerve 3 Motor nerve- Oculomotor Nerve-Controls most eye muscles. Works closely with Cranial Nerves 4 & 6. Controls eye movement, pupil dilation, and pupillary constriction. It also controls the muscles that elevate the upper eyelids. Cranial Nerve 4 Motor nerve- Trochlear Nerve- Controls the downward and outward movement of the eye. Works closely with Cranial Nerves 3 & 6. Can cause vertical Diplopia (double vision). Weakness of downward gaze can cause difficulty in descending stairs. Cranial Nerve 5 Motor and sensory nerve-Trigeminal Nerve-Carries sensory information from most of the head, neck, sinuses, and face. Also carries sensory information for ear and tympanic membrane. Provides motor supply to the muscles of masticulation (chewing), and to some of the muscles on the floor of the mouth. Also provides motor supply to tensor tympani (small muscle in the middle ear which tenses to protect the eardrum).
    [Show full text]
  • The Localization and Complete Extent of the Newly Defined Preganglionic
    Aus der Anatomischen Anstalt der Ludwig-Maximilians-Universität München Lehrstuhl I - Vegetative Anatomie Vorstand: Prof. Dr. med. Jens Waschke The localization and complete extent of the newly defined preganglionic Edinger-Westphal nucleus (EWpg) in human Dissertation zum Erwerb des Doktorgrades der Medizin an der Medizinischen Fakultät der Ludwig-Maximilians-Universität zu München vorgelegt von Laura Ioana Valeanu aus Sibiu, Rumänien Jahr 2020 1 Mit Genehmigung der Medizinischen Fakultät der Universität München Berichterstatter: Prof. Dr. med. Jens Waschke Mitberichterstatter: Prof. Dr. Stefan Glasauer PD Dr. Christoph Trumm Mitbetreuung durch die promovierte Mitarbeiterin: Prof. Dr. rer. nat. Anja Horn-Bochtler Dekan: Prof. Dr. med. dent. Reinhard Hickel Tag der mündlichen Prüfung: 19.05.2020 2 Table of contents ABSTRACT ........................................................................................................................................... 8 ZUSAMMENFASSUNG ...................................................................................................................... 9 I. INTRODUCTION ............................................................................................................................. 11 I.1. Anatomy and function of the inner eye muscles .......................................................... 11 I.1.1. The iris sphincter muscle ................................................................................................. 11 I.1.2. The ciliary muscle ............................................................................................................
    [Show full text]