DOCSLIB.ORG

Anatomy Handbook

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Anatomy Handbook ANATOMY HANDBOOK A Quick Reference for Gross Anatomy S. Christopher Bennett, Ph.D. Version 3.1 – August 30, 2003 ii TABLE OF CONTENTS Introduction ............................................................... 1 Terms of Orientation ....................................................... 2 Terms of Movement .......................................................... 2 Basic Principles ........................................................... 3 HEAD AND NECK Osteology of the Head ...................................................... 5 Joints of the Skull ........................................................ 6 Muscles of the Posterior Triangle .......................................... 9 Prevertebral Muscles ...................................................... 11 Infrahyoid Muscles ........................................................ 13 Suprahyoid Muscles ........................................................ 15 Facial Muscles ............................................................ 17 Muscles of Mastication .................................................... 19 Muscles of the Tongue ..................................................... 21 Extrinsic Muscles of the Eye .............................................. 23 Cranial Nerves ............................................................ 24 Functions of Cranial Nerves ............................................... 25 Spinal Nerves of the Head and Neck ........................................ 27 Arteries of the Head and Neck ............................................. 29 Arteries and Veins of the Brain ........................................... 31 Veins of the Head and Neck ................................................ 33 Cross-section of the Neck ................................................. 34 BACK Osteology of the Postcranial Axial Skeleton ............................... 35 Joints of the Postcranial Axial Skeleton .................................. 36 Intermediate Muscles of the Back .......................................... 39 Erector Spinae Muscles ................................................... 41 Transversospinalis Muscles ................................................ 43 Muscles of the Suboccipital Region ........................................ 45 THORAX AND ABDOMEN Muscles of the Thoracic Wall .............................................. 47 Muscles of the Abdominal Wall ............................................. 49 Muscles of the Pelvis ..................................................... 51 Muscles of the Perineum ................................................... 53 Nerves of the Thorax ...................................................... 55 Nerves of the Abdomen ..................................................... 57 Arteries of the Thorax and Abdomen ........................................ 59 Unpaired Visceral Branches of the Abdominal Aorta ......................... 61 Veins of the Thorax and Abdomen ........................................... 63 UPPER EXTREMITY Osteology of the Pectoral Girdle and Upper Extremity ...................... 64 Joints of the Upper Extremity ............................................. 65 Muscles attaching Upper Extremity to Trunk - Anterior Side ................ 67 Muscles attaching Upper Extremity to Trunk - Posterior Side ............... 69 i Muscles of the Shoulder Joint - Scapular Muscles .......................... 71 Muscles of the Arm ........................................................ 73 Superficial Extensors of the Forearm ...................................... 75 Deep Extensors of the Forearm ............................................. 77 Superficial Flexors of the Forearm ........................................ 79 Deep Flexors of the Forearm ............................................... 81 Other Muscles of the Forearm .............................................. 83 Thenar and Hypothenar Muscles ............................................. 85 Other Muscles of the Hand ................................................. 87 Brachial Plexus ........................................................... 89 Nerves of the Upper Extremity ............................................. 91 Arteries of the Upper Extremity ........................................... 93 Cutaneous Veins of the Upper Extremity .................................... 95 Cross-section of the Arm .................................................. 96 Cross-section of the Forearm .............................................. 97 LOWER EXTREMITY Osteology of the Pelvic Girdle and Lower Extremity ........................ 98 Joints of the Lower Extremity ............................................. 99 Muscles of the Anterior Thigh ............................................ 101 Muscles of the Medial Thigh .............................................. 102 Muscles of the Posterior Thigh ........................................... 103 Lateral Rotators of the Femur ............................................ 107 Gluteal Muscles .......................................................... 109 Muscles of the Anterior Crural Compartment - Dorsiflexors ................ 111 Muscles of the Posterior Crural Compartment - Superficial Plantarflexors . 113 Muscles of the Posterior Crural Compartment - Deep Plantarflexors ........ 115 Muscles of the Lateral Crural Compartment ................................ 117 Muscles of the Dorsum of the Foot ........................................ 119 Muscles of the Sole of the Foot - Layers 1-4 ............................. 121 Nerves of the Lower Extremity ............................................ 125 Nerves and Arteries of the Gluteal Region ................................ 127 Arteries of the Lower Extremity .......................................... 129 Cutaneous Veins of the Lower Extremity ................................... 130 Cross-section of the Thigh ............................................... 131 Cross-section of the Leg ................................................. 132 ii INTRODUCTION This handbook contains much of the basic information about the bones, muscles, nerves, arteries, and veins of the body that is needed in a typical gross anatomy course. Such a course typically follows a regional approach, and so does the handbook. Within regions I have divided the material into small packets of information (a group of muscles; the pattern of arteries; etc.). I organize information visually, and so most packets consist of a drawing and some accompanying textual material, usually arranged on facing pages. I am often asked how one should study anatomy. I do not know how one should do it, I only know how I would study it. First I would divide up the material. In any particular region of the body the muscles can be divided into a number of groups, each containing a small number of muscles. Again I organize information visually so I usually have a drawing or an outline. I have already divided up the material for you. Then to study a group of muscles I would sketch them and label or note the origins, insertions, actions, and innervations. To study the pattern of arteries or nerves I would draw the pattern, name them, note the branching pattern, and where they go or what they do. All the drawings, in this handbook are simple enough that you can draw them. At first I might simply be copying my notes, but soon I would try to put the things down on paper from memory. If I could not remember some things, I would check my notes or look them up in the book, and try again until I had memorized the material and could put it down on a blank sheet of paper. If I can put it down on a blank piece of paper, I know I know it, and I know I can put it down on the test from memory. After having learned the muscles and the patterns of nerves and vessels, one other thing that I find helpful is to look over illustrations in anatomy texts and atlases and make sure you can understand them. 1 TERMS OF ORIENTATION ┌ Anterior - Toward the front, ventral. ┼ └ Posterior - Toward the back, dorsal. ┌ Dorsal - Pertaining to the back, therefore posterior. ┼ └ Ventral - Pertaining to the belly, therefore anterior. ┌ Superior - Higher than, situated above something else. ┼ └ Inferior - Lower than, situated below something else. Median - In the middle, referring to the midline of the body. ┌ Medial - Nearer to the midline of the body. ┼ └ Lateral - Farther to the side from midline of the body. ┌ Proximal - Nearest to the center of the body. ┼ └ Distal - Farthest from the center of the body. ┌ Superficial - At the surface. ┼ └ Deep - Below the surface. TERMS OF MOVEMENT ┌ Extension - Movement that straightens a joint. ┼ └ Flexion - Movement that bends a joint. ┌ ABduction - Movement of a limb or the head away from the midline of the │ body, or in the case of digits away from the axis of the limb. ┼ └ Adduction - Movement of a limb or the head toward the midline of the body, or in the case of digits toward the axis of the limb. ┌ Protraction - Movement (often sliding) of a body part forward. ┼ └ Retraction - Movement (often sliding) that pulls a body part backward. ┌ Elevation - Movement that lifts a body part up. ┼ └ Depression - Movement that pushes a body part down. Rotation - Movement of a limb about its axis. Medial and lateral rotation move the front of the limb medially and laterally, respectively. Circumduction - Movement that combines two other movements to move a body part in circles. For example, swinging the upper extremity in a circle combines flexion, extension, adduction, and aBduction.
Load more

Recommended publications
  • Unusual Organization of the Ansa Cervicalis: a Case Report
    CASE REPORT ISSN- 0102-9010 UNUSUAL ORGANIZATION OF THE ANSA CERVICALIS: A CASE REPORT Ranjana Verma1, Srijit Das2 and Rajesh Suri3 Department of Anatomy, Maulana Azad Medical College, New Delhi-110002, India. ABSTRACT The superior root of the ansa cervicalis is formed by C1 fibers carried by the hypoglossal nerve, whereas the inferior root is contributed by C2 and C3 nerves. We report a rare finding in a 40-year-old male cadaver in which the vagus nerve fused with the hypoglossal nerve immediately after its exit from the skull on the left side. The vagus nerve supplied branches to the sternohyoid, sternothyroid and superior belly of the omohyoid muscles and also contributed to the formation of the superior root of the ansa cervicalis. In this arrangement, paralysis of the infrahyoid muscles may result following lesion of the vagus nerve anywhere in the neck. The cervical location of the vagus nerve was anterior to the common carotid artery within the carotid sheath. This case report may be of clinical interest to surgeons who perform laryngeal reinnervation and neurologists who diagnose nerve disorders. Key words: Ansa cervicalis, hypoglossal nerve, vagus nerve, variations INTRODUCTION cadaver. The right side was normal. The neck region The ansa cervicalis is a nerve loop formed was dissected and the neural structures in the carotid by the union of superior and inferior roots. The and muscular triangle regions were exposed, with superior root is a branch of the hypoglossal nerve particular attention given to the organization of the containing C1 fibers, whereas the inferior root is ansa cervicalis.
    [Show full text]
  • Tentorium Cerebelli: the Bridge Between the Central and Peripheral Nervous System, Part 2
    Open Access Review Article DOI: 10.7759/cureus.5679 Tentorium Cerebelli: the Bridge Between the Central and Peripheral Nervous System, Part 2 Bruno Bordoni 1 , Marta Simonelli 2 , Maria Marcella Lagana 3 1. Cardiology, Foundation Don Carlo Gnocchi, Milan, ITA 2. Osteopathy, French-Italian School of Osteopathy, Pisa, ITA 3. Radiology, IRCCS Fondazione Don Carlo Gnocchi Onlus, Milan, ITA Corresponding author: Bruno Bordoni, [email protected] Abstract The tentorium cerebelli is a meningeal portion in relation to the skull, the nervous system, and the cervical tract. In this second part, the article discusses the systematic tentorial relationships, such as the central and cervical neurological connections, the venous circulation and highlights possible clinical alterations that could cause pain. To understand the function of anatomy, we should always remember that every area of the human body is never a segment, but a functional continuum. Categories: Physical Medicine & Rehabilitation, Anatomy, Osteopathic Medicine Keywords: tentorium cerebelli, fascia, pain, venous circulation, neurological connections, cranio Introduction And Background Cervical neurological connections The ansa cervicalis characterizes the first cervical roots and connects all anterior cervical nerve exits with the inferior floor of the oral cavity, the trigeminal system, the respiratory control system, and the sympathetic system. The descending branch of the hypoglossal nerve anastomoses with C1, forming the ansa hypoglossi or ansa cervicalis superior [1]. The inferior root of the ansa cervicalis, also known as descendens cervicalis, is formed by ascendant fibers from spinal nerves C2-C3 and occasionally fibers C4, lying anteriorly to the common carotid artery (it passes laterally or medially to the internal jugular vein upon anatomical variations) [1].
    [Show full text]
  • A Source of Complication in Vagus Nerve Stimulation
    PEDIATRICS CASE REPORT J Neurosurg Pediatr 15:535–538, 2015 The “vagal ansa”: a source of complication in vagus nerve stimulation Chittur Viswanathan Gopalakrishnan, MS, MCh,1 John R. W. Kestle, MD,1 and Mary B. Connolly, MB, FRCP(C)2 1Division of Neurosurgery, Department of Surgery, University of British Columbia and BC Children’s Hospital; and 2Division of Neurology, Department of Paediatrics, University of British Columbia and BC Children’s Hospital, Vancouver, British Columbia, Canada A 16-year-old boy underwent vagus nerve stimulation for treatment-resistant multifocal epilepsy. During intraoperative system diagnostics, vigorous contraction of the ipsilateral sternomastoid muscle was observed. On re-exploration, a thin nerve fiber passing from the vagus to the sternomastoid was found hooked up in the upper electrode. Detailed inspec- tion revealed an abnormal course of the superior root of the ansa cervicalis, which descended down as a single nerve trunk with the vagus and separated to join the inferior root. The authors discuss the variation in the course of the ansa cervicalis and how this could be a reason for postoperative neck muscle contractions. http://thejns.org/doi/abs/10.3171/2014.10.PEDS14259 KEY WORDS ansa cervicalis; variation; vagus nerve stimulation; epilepsy; complication; peripheral nerve HE ansa cervicalis, located in the anterior triangle of We describe an intraoperative complication noticed the neck, is formed by the anterior rami of the first during testing of the VNS system after placement of the 3 or 4 cervical spinal nerves. This nerve loop in- electrodes and the pulse generator. To the best of our Tnervates the infrahyoid muscles.5 It is frequently encoun- knowledge, it has not been previously reported.
    [Show full text]
  • A Case of the Human Sternocleidomastoid Muscle Additionally Innervated by the Hypoglossal Nerve
    Okajimas Folia Anat. Jpn., 69(6): 361-368, March, 1993 A Case of the Human Sternocleidomastoid Muscle Additionally Innervated by the Hypoglossal Nerve By Masahiro KOIZUMI, Masaharu HORIGUCHI, Shin'ichi SEKIYA, Sumio ISOGAI and Masato NAKANO Department of Anatomy, Iwate Medical University School of Medicine. Morioka, 020 Japan -Received for Publication, October 19, 1992- Key Words: Sternocleidomastoid muscle, Hypoglossal nerve, Superior sternoclavicular muscle (Hyrtl), Dual nerve supply, Gross anatomy Summary: An anomalous nerve supply from the hypoglossal nerve (XII) to the sternocleidomastoid muscle (SM) was observed in the right neck of an 82-year-old Japanese female. This nerve branch arose from the hypoglossal nerve at the origin of the superior root of the ansa cervicalis. The nerve fiber analysis revealed that this branch consisted of fibers from the hypoglossal nerve, the first and the second cervical nerves and had the same component as the superior root of the ansa cervicalis. SM appeared quite normal and the most part was innervated by the accessory nerve and a branch from the cervical plexus. The anomalous branch from XII supplied the small deep area near the anterior margin of the middle of the sternomastoid portion of SM. It is reasonable to think that the small deep area of SM, which was innervated by the anomalous branch from XII, occurs as the result of fusion of the muscular component from infrahyoid muscles. If the muscular component does not fuse with SM, it is thought to appear as an aberrant muscle such as the superior sternoclavicular muscle (Hyrtl) which is also supplied from a branch of the superior root of the ansa cervicalis.
    [Show full text]
  • An Unusual Superior Root of the Ansa Cervicalis
    Open Access Case Report DOI: 10.7759/cureus.4558 An Unusual Superior Root of the Ansa Cervicalis Shogo Kikuta 1 , Joe Iwanaga 2 , Jingo Kusukawa 3 , R. Shane Tubbs 4 1. Seattle Science Foundation, Seattle, USA 2. Medical Education and Simulation, Seattle Science Foundation, Seattle, USA 3. Dental and Oral Medical Center, Kurume University School of Medicine, Kurume, JPN 4. Neurosurgery, Seattle Science Foundation, Seattle, USA Corresponding author: Joe Iwanaga, [email protected] Abstract The ansa cervicalis is located around the carotid sheath and forms a neural loop, which consists of superior and inferior roots. It innervates the infrahyoid muscles. Anatomical variations of the superior root of the ansa cervicalis are uncommon. Herein, we present an extremely rare case of the superior root of the ansa cervicalis arising both from the hypoglossal and vagus nerves. Categories: Miscellaneous Keywords: ansa cervicalis, anatomy, neck surgery, variation, vagus nerve Introduction The ansa cervicalis is located deep into the sternocleidomastoid muscle and innervates the infrahyoid muscles. It is formed by two roots, superior and inferior. The fibers from the ventral rami of the first and second cervical spinal nerves (C1-C2) hitchhike along the hypoglossal nerve (HN) for a distance of 3-4 cm to become the superior root of the ansa cervicalis [1-3]. The superior root consistently leaves the HN and descends along the anterior wall of the carotid sheath. The inferior root arises from the ventral rami of the second and third cervical spinal nerves (C2-C3). The superior and inferior roots join to form a neural loop anterior to the internal jugular vein (IJV), in most cases [4].
    [Show full text]
  • Communication of the Anterior Branch of the Great Auricular Nerve with the Cervical Branch of Facial Nerve and Its Variant Nerve Endings Deep in the Parotid Gland
    Int. J. Morphol., 30(3):840-842, 2012. Communication of the Anterior Branch of the Great Auricular Nerve with the Cervical Branch of Facial Nerve and its Variant Nerve Endings Deep in the Parotid Gland Comunicación del Ramo Anterior del Nervio Auricular Mayor con el Ramo Cervical del Nervio Facial y sus Terminaciones Nerviosas Profundas Variantes en la Glándula Parótida *Srinivasa Rao Sirasanagandla; *Satheesha Nayak B.; **Kumar M. R. Bhat & *Swamy Ravindra S. RAO, S. S.; NAYAK, B. S.; BHAT, K. M. R. & RAVINDRA, S. S. Communication of the anterior branch of the great auricular nerve with the cervical branch of facial nerve and its variant nerve endings deep in the parotid gland. Int. J. Morphol., 30(3):840-842, 2012. SUMMARY: The communications between the branches of cervical plexus and cervical branch of facial nerve are common and are well known. However, this communication usually occurs between the transverse cervical nerve and cervical branch of facial nerve. During routine dissection classes for the Medical undergraduate students, we came across an anatomical variant of anterior division of great auricular nerve. This variation was found in a 60-year-old male cadaver of South Indian origin and it was unilateral. The great auricular nerve arose from the loop of ventral rami of C2 and C3 spinal nerves and divided into anterior and posterior branches. The anterior branch ran obliquely upwards and forwards on the surface of the sternocleidomastoid muscle along with the external jugular vein towards the apex of parotid gland and divided into many branches. One of these branches gave a communicating branch to cervical branch of facial nerve outside the parotid gland.
    [Show full text]
  • The Cervical Plexus by Prof
    The Cervical Plexus By Prof. Dr. Imran Qureshi The Cervical Plexus is formed by the ventral rami of C1, C2, C3, and C4. It supplies: o Areas of the Skin o The Respiratory Diaphragm o The Strap muscles of the Anterior Triangle of the Neck, and o The nerves to The Sternocleidomastoid, Trapezius, Scalenes, Levator Scapulae, Longus Coli, Longus Capitis etc. I. Branches to the Skin: These appear in the posterior triangle at the midpoint of the posterior border of the sternocleidomastoid. They are: The Greater Auricular Nerve, which crosses the Sternocleidomastoid obliquely, posterior to the external jugular vein and ascends toward the lobe of the ear, Lesser Occipital Nerve, which parallels the posterior border of Sternocleidomastoid and ascends toward the occipital region, Anterior Cutaneous (Transverse Cervical) Nerve, which crosses transversely across the Sternocleidomastoid to reach the skin of the anterior triangle of the neck, The Supraclavicular trunk, which passes from under cover of the Sternocleidomastoid and divides into: The Lateral supraclavicular nerve, The Intermediate supraclavicular nerve, and The Medial supraclavicular nerve. The Lateral supraclavicular passes superficial to the trapezius to supply the skin of the shoulder tip. The Intermediate and Medial supraclavicular nerves pass superficial to the clavicle to the skin of the pectoral region. 1 II. Nerve to Respiratory Diaphragm (Phrenic Nerve): This nerve, which arises from the ventral rami of C3, C4, and C5, is the motor nerve of the diaphragm. It also supplies sensory fibers, including pain, to the central area. The contribution from C5 may join that from C3 and C4 directly, or secondarily as a branch from the nerve to the subclavius muscle.
    [Show full text]
  • A Case Report of Complex Auricular Neuralgia Treated with the Great Auricular Nerve and Facet Blocks
    Journal name: Journal of Pain Research Article Designation: CASE REPORT Year: 2017 Volume: 10 Journal of Pain Research Dovepress Running head verso: Eghtesadi et al Running head recto: Complex auricular neuralgia treated with GAN and facet blocks open access to scientific and medical research DOI: http://dx.doi.org/10.2147/JPR.S126923 Open Access Full Text Article CASE REPORT A case report of complex auricular neuralgia treated with the great auricular nerve and facet blocks Marzieh Eghtesadi1 Background: The great auricular nerve is a cutaneous branch of the cervical plexus originating Elizabeth Leroux2 from the C2 and C3 spinal nerves. It innervates the skin over the external ear, the angle of the Grisell Vargas-Schaffer3 mandible and the parotid gland. It communicates with the ansa cervicalis. Great auricular neu- ralgia is rarely diagnosed in clinical practice and can be refractory. We present a new approach 1Department of Pain Clinic, Headache Management, Centre Hospitalier de using ultrasound-guided nerve blocks. l’Université de Montréal (CHUM), Centre Case: We present a case of a 41-year-old female with paroxysmal ear pain accompanied by de Recherche de l’Université de Montréal (CRCHUM), 2Department of General dysautonomia, tingling in the tongue, dysphagia, dysarthria and abdominal symptoms. No Neurology, Headache Management, significant findings were found on cervical and brain imaging. The patient responded partially Centre Hospitalier de l’Université de Montréal (CHUM), Centre de Recherche to a great auricular nerve block. A combined approach using this block with facet block of C2 de l’Université de Montréal (CRCHUM), and C3 induced a more pronounced and prolonged benefit.
    [Show full text]
  • Anatomical Study of the Human Ansa Cervicalis Nerve and Its Variations
    International Journal of Anatomy and Physiology ISSN: 2326-7275 Vol. 2 (3), pp. 014-019, March, 2013. Available online at www.internationalscholarsjournals.org © International Scholars Journals Full length research paper Anatomical study of the human ansa cervicalis nerve and its variations Ahmed M.S. Hegazy Anatomy and Embryology, Department of Anatomy, Faculty of Medicine, Benha University, Egypt. E-Mail: [email protected] Accepted 27 February, 2013 With the expanding use of the ansa cervicalis nerve for laryngeal reinnervation procedures. So the aim of this work was to study the anatomical variations of ansa cervicalis in its roots, course and branching pattern. Twenty five Egyptian necks (50 sides) were dissected. The results showed that the ansa cervicalis (AC) consisted of two roots: superior and inferior roots. These two roots joined together to form a nerve loop. The superior root of AC originated from the hypoglossal nerve in 100%.The superior root of AC descended in front of the external carotid artery in 68% and in front of the internal carotid artery in 32%. The inferior root of AC was derived from the ventral rami of C2 and C3 in 84% and from C2 in 16%. There were four morphological forms of the loop of ansa cervicalis: I- U-shaped loop in 84%. II- Y-shaped loop in 8%. III- double fused Y-shaped loop in 4%.VI- double separate Y-shaped loop in 4%. The superior root of AC gave a branch to the superior belly of omohyoid in 96% and a branch to sternomastoid in 24% . The inferior root of AC gave a branch to inferior belly of omohyoid and a communicating branch to phrenic nerve in 4%.
    [Show full text]
  • The Carotid Endarterectomy Cadaveric Investigation for Cranial Nerve Injuries: Anatomical Study
    brain sciences Article The Carotid Endarterectomy Cadaveric Investigation for Cranial Nerve Injuries: Anatomical Study Orhun Mete Cevik 1,2,3 , Murat Imre Usseli 1, Mert Babur 2, Cansu Unal 3,4, Murat Sakir Eksi 1, Mustafa Guduk 1, Talat Cem Ovalioglu 2, Mehmet Emin Aksoy 3 , M. Necmettin Pamir 1 and Baran Bozkurt 1,3,* 1 Department of Neurosurgery, Acıbadem Mehmet Ali Aydinlar University, 34662 Istanbul, Turkey; [email protected] (O.M.C.); [email protected] (M.I.U.); [email protected] (M.S.E.); [email protected] (M.G.); [email protected] (M.N.P.) 2 Department of Neurosurgery, Bakırkoy Training and Research Hospital for Psychiatric and Nervous Diseases, Health Sciences University, 34147 Istanbul, Turkey; [email protected] (M.B.); [email protected] (T.C.O.) 3 (CASE) Center of Advanced Simulation ant Education, Acıbadem Mehmet Ali Aydinlar University, 34684 Istanbul, Turkey; [email protected] (C.U.); [email protected] (M.E.A.) 4 School of Medicine, Acıbadem Mehmet Ali Aydinlar University, 34684 Istanbul, Turkey * Correspondence: [email protected]; Tel.: +90-533-315-6549 Abstract: Cerebral stroke continues to be one of the leading causes of mortality and long-term morbidity; therefore, carotid endarterectomy (CEA) remains to be a popular treatment for both symptomatic and asymptomatic patients with carotid stenosis. Cranial nerve injuries remain one of the major contributor to the postoperative morbidities. Anatomical dissections were carried out on 44 sides of 22 cadaveric heads following the classical CEA procedure to investigate the variations of the local anatomy as a contributing factor to cranial nerve injuries.
    [Show full text]
  • A RARE CASE of BILATERAL VARIANT ANSA CERVICALIS and REVIEW of LITERATURE Suma H Y 1, Yogesh a S 1, Shanthini S 2
    International Journal of Anatomy and Research, Int J Anat Res 2019, Vol 7(2.2):6565-70. ISSN 2321-4287 Case Report DOI: https://dx.doi.org/10.16965/ijar.2019.168 A RARE CASE OF BILATERAL VARIANT ANSA CERVICALIS AND REVIEW OF LITERATURE Suma H Y 1, Yogesh A S 1, Shanthini S 2. 1 Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India. 2 Sri Lakshmi Narayana Institute of Medical Sciences, Puducherry, India. ABSTRACT Ansa cervicalis is a nerve loop that is embedded in the anterior wall of carotid sheath of the neck. It is formed by descendent hypoglossi and descendens cervicalis. It supplies the infrahyoid muscles. During routine dissection, a rare variant in the morphology of Ansa cervicalis was observed in adult male cadaver. The variant ansa cervicalis exhibited two loops, and was present bilaterally. The formation, course and relations of the nerve loop is complex. During literature search, we came across studies which propose different classifications. Hence we have added a note on the different classifications. Ansa cervicalis is important since it can be used in nerve-nerve anastomosis, nerve-muscle pedicle implantation in relation to reconstructive surgeries of larynx. Hence, the knowledge of variations in the formation, and distribution is relevant. It can affect the outcome during reinnervation surgeries following recurrent laryngeal paralysis and surgeries around this area of neck. KEY WORDS: Ansa Cervicalis, Cervical Plexus, Reinnervation Of Larynx, Infrahyoid Muscles, Recurrent Laryngeal Nerve
    [Show full text]
  • The Ansa Cervicalis Revisited
    Folia Morphol. Vol. 66, No. 2, pp. 120–125 Copyright © 2007 Via Medica O R I G I N A L A R T I C L E ISSN 0015–5659 www.fm.viamedica.pl The ansa cervicalis revisited M. Loukas1, 2, A. Thorsell1, R.S. Tubbs3, T. Kapos4, R.G. Louis Jr.1, M. Vulis1, R. Hage1, R. Jordan1 1Department of Anatomical Sciences, St. George’s University, School of Medicine, Grenada, West Indies 2Department of Education and Development, Harvard Medical School, Boston, MA, USA 3Department of Cell Biology and Paediatric Neurosurgery, University of Alabama at Birmingham, USA 4Department of Advanced Graduate Prosthodontics, Harvard School of Dental Medicine, Boston, MA, USA [Received 9 January 2007; Revised 8 March 2007; Accepted 8 March 2007] Recurrent laryngeal nerve paralysis represents a major complication in oesoph- ageal cancer surgery. Nerve-muscle transplantation to the paraglottic space after resection of the recurrent laryngeal nerve with the ansa cervicalis (AC) has recently become the procedure of choice. The aim of this study was to investigate the anatomical variations of AC in order to avoid iatrogenic injuries and facilitate sur- gical procedures. We examined 100 adult human formalin-fixed cadavers. The ansa cervicalis showed a great degree of variation regarding origin and distribu- tion. The origin of the superior root of AC was found to be superior to the digas- tric muscle in 92% of the cases. Its vertical descent was found to be superficial to the external carotid artery in 72% and superficial to the internal carotid artery in 28% of the specimens. The inferior root of AC was derived from the primary rami of C2 and C3 in 38%, from C2, C3 and C4 in 10%, from C3 in 40% and from C2 in 12% of the cases.
    [Show full text]