cranial nerves

Question 1

what are the trigeminal nerve (V) sensory functions?

Answer 1

• General sensation of the face anterior 2/3 tongue, hard palate, cheeks
• Muscles of mastication: masseter, temporalis, medial & lateral pterygoids

Question 2

what are the trigeminal nerve (V) motor functions?

Answer 2

• Muscles of masication -> oral preparation and chewing
  Mylohylod, anterior belly of digastric (hyolaryngeal excursion)
• Tensor veli palitni (tenses soft palate; assists velopharyngeal seals)

Question 3

what are the facial nerve (VII) sensory functions?

Answer 3

• Special taste sensation anterior 2/3 of tongue

Question 4

what are the facial nerve (VI) motor functions?

Answer 4

• Muscles of facial expression: Orbicularis oris (lip seal), Buccinator (buccinator press)
• Stylohyoid, posterior belly of digastric: Hylolaryngeal excursion – hyoid elevation
• Secretomotor-submandibular & sublingual salivary glands

Question 5

what are the glossopharyngeal nerve sensory functions?

Answer 5

• Special taste sensation posterior 1/3 of tongue
• General sensation posterior 1/3 of tongue, soft palate, faucial arches (triggering reflexive swallow)
• Gag sensation (gag reflex)

Question 6

what are the glossopharyngeal nerve sensory functions?

Answer 6

• Stylopharyngeus: raises the pharynx compressing the lateral laryngeal walls and helping in the pharyngeal compression over the food bolus during deglutition
• Part of the pharyngeal plexus – travels with X to help innervate the pharyngeal constrictors
• Secretomotor – parotid salivary gland

Question 7

what are the vagus nerve sensory functions?

Answer 7

• General sensation: epiglottis, pharynx, valleculae pyriform sinuses, larynx/vocal folds
• Swallow initiation
• Detecting pharyngeal residue
• Detecting aspiration/penetrations
• Special taste sensation – epiglottis

Question 8

what are the vagus nerve motor functions?

Answer 8

• Muscles of the soft palate
• Levator veli palitini (velopharyngeal seal)
• Palatoglossus (Glossopalatal seal)
• Pahaltopharyngeus, uvulae muscle
• Pharyngeal constrictors (pharyngeal constriction)
• Intrinsic muscles of the larynx (vocal fold adduction / glottal seal, cough
• Cricopharyngeus / UES (UES relxation)
• Oesophagus (peristaltic wave)

Question 9

what are the accessory nerve motor functions?

Answer 9

• Muscles of the head and neck
• Pharyngeal plexus (network of nerves) – many of the muscles of the oropharynx are supplied by the pharyngeal plexus, which is made up of various branches from cranial nerves IX, X, XI

Question 10

what are the hypoglossal nerve motor functions?

Answer 10

• Intrinsic muscles of the tongue
• Extrinsic muscles of the tongue: hypoglossus, genioglossus, styloglossus
• Geniohyoid – involved in hyoid elevation