
<p>Important embryological structures across vertebrate species</p>
<ul>
  <li>There are six in humans (but no fifth arch!)</li>
  <li>
    The first three arches contribute to structures above the larynx while the last two contribute
    to the larynx and trachea
  </li>
</ul>
<ul>
  <li>First pharyngeal arch: muscles of mastication supplied by CNV3</li>
  <ul>
    <li>Temporalis</li>
    <li>Masseter</li>
    <li>Medial and lateral pterygoid</li>
  </ul>
  <li>Second pharyngeal arch: muscle of facial expression supplied by CNVII</li>
  <ul>
    <li>Frontalis</li>
    <li>Orbicularis oris</li>
    <li>Orbicularis oculi</li>
    <li>Platysma&nbsp;</li>
  </ul>
  <li>The exceptions are</li>
  <ul>
    <li>
      Buccinator: derived from the second pharyngeal arch and is supplied by the facial nerve but
      plays a role in mastication&nbsp;
    </li>
    <li>
      Digastric: derived from both arches. Anterior belly supplied by trigeminal and posterior belly
      by facial.
    </li>
  </ul>
</ul>
<div className="bg-blue-200 px-4 rounded-md shadow-lg dark:text-gray-700">
  <table>
    <tbody>
      <tr>
        <td>&nbsp;</td>
        <td>
          <strong>First pharyngeal arch (mandibular)</strong>
        </td>
        <td>
          <strong>Second pharyngeal arch (hyoid)</strong>
        </td>
      </tr>
      <tr>
        <td>
          <strong>Skeletal</strong>
        </td>
        <td>Malleus</td>
        <td>Stapes&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Incus&nbsp;</td>
        <td>Temporal styloid process</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Maxilla</td>
        <td>Stylohyoid ligament</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Mandible</td>
        <td>Lesser cornu of hyoid</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Spine of sphenoid</td>
        <td>&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Sphenomandibular ligament</td>
        <td>&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Palatine&nbsp;</td>
        <td>&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Squamous temporal</td>
        <td>&nbsp;</td>
      </tr>
      <tr>
        <td>
          <strong>Muscles</strong>
        </td>
        <td>Masseter&nbsp;</td>
        <td>Frontalis&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Medial and lateral pterygoids</td>
        <td>Orbicularis oris and oculi</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Temporalis</td>
        <td>Platysma&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Mylohyoid</td>
        <td>Occipitofrontalis&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Anterior belly of digastric</td>
        <td>Stylohyoid&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>Tensor veli palatini and tensor tympani</td>
        <td>Posterior belly of digastric</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>&nbsp;</td>
        <td>Stapedius&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>&nbsp;</td>
        <td>Auricular&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>&nbsp;</td>
        <td>Buccinator</td>
      </tr>
      <tr>
        <td>
          <strong>Nerve supply</strong>
        </td>
        <td>Mandibular and maxillary branches of trigeminal</td>
        <td>Facial</td>
      </tr>
      <tr>
        <td>
          <strong>Arteries</strong>
        </td>
        <td>Maxillary</td>
        <td>Stapedial artery</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
        <td>External carotid</td>
        <td>Hyoid artery</td>
      </tr>
      <tr>
        <td>
          <strong>Other</strong>
        </td>
        <td>Thyroid (derived from both.C-cells are derived from the fourth laryngeal pouches)</td>
      </tr>
    </tbody>
  </table>
</div>

## Third arch
<ul>
  <li>Hyoid bone</li>
  <li>Thymus</li>
  <li>Common carotid</li>
  <li>Internal carotid</li>
  <li>Glossopharyngeal nerve: innervates the third arch</li>
</ul>

## Fourth arch
<ul>
  <li>Cricothyroid muscle</li>
  <li>Thyroid cartilage</li>
  <li>Epiglottic cartilage</li>
  <li>Vagus nerve: innervates the fourth and sixth arches</li>
  <li>Subclavian</li>
  <li>Aortic arch</li>
</ul>

## Tongue
<ul>
  <li>Developed from first, third and fourth pharyngeal arches</li>
  <li>Intrinsic muscles derived from occipital myotomes</li>
  <li>Sulcus terminalis divides the tongue into anterior two-third and posterior one-third</li>
  <ul>
    <li>Has vallate papillae anterior to the sulcus</li>
  </ul>
  <li>Supplied by:</li>
  <ul>
    <li>Hypoglossal nerve (almost all muscles)</li>
    <li>Vagus nerve (supplies palatoglossus)</li>
    <li>
      Parasympathetic and sensory/taste fibres to the posterior third derived from the otic ganglion
      (from glossopharyngeal)
    </li>
    <li>Taste supply to the anterior two-thirds from the chorda tympani</li>
    <li>Sensory supply to the anterior two-thirds from the mandibular branch of the trigeminal</li>
  </ul>
</ul>


Neuroanatomy

Muscles And Pharyngeal Arches

Intro

FRCOphth Part 1 Study Notes

Orbit and ocular adnexae

Orbit

Extraocular Muscles

Orbital Blood Vessels

Paranasal Sinuses

Lacrimal Glands

Tear Film

Eyelids

Blinking

Anterior segment - ocular surface

Conjunctiva

Conjunctivitis

Sclera

Cornea

Corneal Structure And Development

Corneal Physiology

AC to Lens

Angle

Ciliary Body

Aqueous Humour Dynamics

Iris

Pupil

Lens

Posterior segment

Choroid

Vitreous

Retinal Macrostructure

Neurosensory Retina

Retinal Pigment Epithelium

Venous Sinuses

Cerebral Ventricles

Cerebral Blood Supply

Supranuclear Gaze Pathways

Head And Neck Autonomic Nervous Supply

Head And Neck Glands

Osteology

Nerves

Extraocular Nerves

Sensory Nerves

Physiology

Physics Of Blood Flow

Neuronal Control Of Blood Vessels

Oxygen-Haemoglobin Dissociation Curve

Cytochrome p450

Pituitary Gland

Thyroid Hormone Production

Insulin

Glucagon

Parathyroid Hormone

Corticosteroids

Catecholamines

Cardiac Cycle

Renal Physiology

Fluid Balance

Acid-Base Balance

Muscle Physiology

Sensory Fibres

Cutaneous Receptors

Endocytosis

Glycosaminoglycans

Condensed Ocular Biochemistry

Eye Movements

Accomodation

Vision

Visual Cycle And Phototransuction

Visual Pathway

Visual Acuity

Colour Vision

Binocular Vision

Pathology

Collagen

Tissue Damage

Inflammation

Disease Entities

Wound Healing

Thrombosis / Atherosclerosis

Cell Growth

Neoplasia

Histopathology

Nystagmus

Free Radicals And Antioxidants

Immunology

Ocular Immunology

Microbiology

Viral Infections

Bacterial Infections

Fungal Infections

Protozoa

Nematodes

Antimicrobials

Genetics

Chromosomes

Mitosis

Meiosis

Genes

Polypeptide Synthesis

Histones

MicroRNA

Hardy-Weinberg Equilibrium

Mutations

Chromosome Defects

Autosomal Inheritance

X-Linked Inheritance

Mitochondrial Inheritance

Multifactorial Inheritance