
<ul>
  <li>Ophthalmic and maxillary divisions of trigeminal nerves</li>
</ul>

## Ophthalmic nerve
<ul>
  <li>Smallest division of the trigeminal</li>
  <li>Pure sensory</li>
  <li>Arises from trigeminal ganglion</li>
  <li>
    Enters lateral wall of cavernous sinus (below oculomotor and trochlear nerves, above the
    maxillary)
  </li>
  <li>Receives sympathetic branches from internal carotid plexus</li>
  <li>Gives off three branches prior to entering the orbit</li>
  <li>Branches</li>
  <ul>
    <li>Lacrimal&nbsp;</li>
    <ul>
      <li>Smallest branch, enters outwith the tendinous ring</li>
      <li>
        Joins the branch from the zygomaticotemporal branch of the zygomatic branch of the maxillary
        nerve which contains parasympathetic secretomotor fibres from the facial nerve
      </li>
      <li>Also supplies the conjunctiva and skin of upper eyelid</li>
    </ul>
    <li>Frontal: largest branch</li>
    <ul>
      <li>Enters the orbit through the SOF outwith tendinous ring</li>
      <li>Passes forward on the surface of the levator and gives branches halfway along</li>
      <li>
        Supraorbital: leaves via the supraorbital notch to supply the skin and conjunctiva of upper
        eyelid
      </li>
      <li>Supratrochlear: also supplies skin and conjunctiva of upper eyelid</li>
    </ul>
    <li>Nasociliary</li>
    <ul>
      <li>Enters orbit through SOF within tendinous ring between branches of oculomotor</li>
      <li>
        Long ciliary branches arise as it crosses the optic nerve and pierce sclera close to optic
        nerve. Then pass forward in the choroid to the CB, iris (sympathetic) and cornea (sensory)
      </li>
      <li>
        Infratrochlear branch: supplies lacrimal sac, conjunctiva, skin of medial upper and lower
        eyelids and lateral nose
      </li>
      <li>
        Other branches supply ethmoidal (anterior and posterior ethmoidal nerves) and sphenoidal air
        sinuses
      </li>
    </ul>
  </ul>
</ul>
<ClinicalCorrelate>
  <p>
    The infratrochlear nerve is the terminal branch of the nasociliary: Hutchinson's sign is the
    classic lesions of herpes zoster seen on the side/tip of nose indicating infratrochlear
    involvement suggesting the long ciliary nerves could be too (which also supply the globe, see
    below).
  </p>
</ClinicalCorrelate>

## Facial nerve
<ul>
  <li>Both motor and sensory</li>
  <li>3 nuclei</li>
  <ul>
    <li>Main motor: pons.</li>
    <ul>
      <li>
        Portion supplying muscles of the upper face receive bilateral innervation, whereas the
        portion supplying the lower face receive contralateral innervation only
      </li>
    </ul>
    <li>Parasympathetic: posterolateral to main motor nucleus</li>
    <ul>
      <li>Superior salivatory and lacrimal nuclei</li>
      <li>Afferent fibres from the hypothalamus</li>
    </ul>
    <li>Sensory: upper part of nucleus tractus solitarius</li>
  </ul>
  <li>Motor and sensory roots</li>
  <li>Emerge from the cerebellopontine angle</li>
  <li>Posterior cranial fossa</li>
  <li>Enters internal acoustic meatus then facial canal into inner ear</li>
  <li>
    Turns backwards to descend along posterior wall of middle ear to exit via the stylomastoid
    foramen
  </li>
</ul>

## Olfactory nerve
<ul>
  <li>Originates in the epithelium of the nasal mucosa</li>
  <li>Neurones condense into the olfactory tract</li>
  <li>Passes along olfactory groove in the cribiform plate</li>
  <li>The anterior olfactory nucleus lies posterior to this</li>
  <li>Tract divides into medial and lateral striae</li>
  <ul>
    <li>
      Medial striae contains fibres from the anterior nucleus and pass to the anterior commissure
    </li>
    <li>
      Lateral striae terminates in the amygdala and the primary olfactory cortex at the anterior end
      of the parahippocampal gyrus and uncus
    </li>
  </ul>
</ul>

<HotTopic>
  <p>The olfactory signals are unique in bypassing the thalamus</p>
</HotTopic>


Neuroanatomy

Sensory Nerves

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

Muscles And Pharyngeal Arches

Extraocular 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