Case 5 anatomy Flashcards
the cribriform plate is part of which bone?
ethmoid bone
where does the optic nerve terminate?
in the lateral geniculate nucleus
where does the trochlear nerve arise from?
the dorsal surface of the midbrain
describe the course of the trochlear nerve
- Arises from the dorsal surface of the midbrain
- Passes anteriorly around the brainstem
- Pierces the dura mater at the margin of the tentorium cerebelli
- Passes in the lateral wall of the cavernous sinus
- Exits the skull through the superior orbital fissure and enters the orbit
which nerves arise from the midbrain?
- oculomotor
- trochlear
which nerves arise from the pons?
trigeminal
where do you find the trigeminal ganglion?
on the anterior surface of the petrous temporal bone
describe the course of the ophthalmic branch
- Passes forwards in the lateral cavernous sinus
* Divides into three branches which exit the skull through the superior orbital fissure to enter the orbit
where does the maxillary branch exit the skull? where does it go next?
through the foramen rotundum
- Enters the pterygopalatine fossa
- It gives off numerous branches within the pterygopalatine fossa
what’s the terminal branch of the maxillary nerve? where does it go?
Its terminal branch, the infraorbital nerve, exits the fossa through the inferior orbital fissure to enter the orbit
where does the mandibular branch exit the skull?
through the foramen ovale
where does the manibular branch give off its branches?
in the infratemporal fossa
what are the branches of the ophthalmic branch?
- Frontal
- Nasociliary
- Lacrimal
(FML)
what are the branches of the maxillary branch?
- Infraorbital
- Zygomatic
- Nasopalatine
- Greater palatine
- Lesser palatine
- Anterior superior alveolar
- Middle superior alveolar
- Posterior superior alveolar
what are the branches of the mandibular branch?
- Meningeal
- Deep temporal
- Auriculotemporal
- Masseteric
- Nerve to medial pterygoid
- Buccal
- Incisive
- Lingual
- Inferior alveolar
- Mental
- Nerve to mylohyoid
what is the sensory distribution of the different branches of the trigeminal nerve?
- Ophthalmic = forehead and backwards, eyebrows and medial part of nose
- Maxillary = up to forehead, over cheek bone, lateral parts of nose
- Mandibular = up to forehead, across side of cheeks, over chin
what are the muscles that the mandibular division provides innervation to?
8 muscles:
• Four muscles are the muscles of mastication; masseter, temporalis, medial pterygoid and lateral pterygoid
• Anterior belly of digastric, mylohyoid, tensor tympani, tensor veli palatini are also innervated by mandibular nerve
what does the tensor veli palatini do?
tenses the soft palate
what innervates the stapedius muscle?
facial nerve
which nerves arise from the pons-medullary junction?
abducent, facial and glossopharyngeal nerves
describe the pathway of the abducent nerve
- Arises from the brain stem at the pons-medullary junction
- Traverse the pontine cistern of the subarachnoid space
- Pierces the dura mater at the clivus
- Passes through the cavernous sinus parallel to the internal carotid artery
- Exits the skull through the superior orbital fissure and enters the orbit
which cranial nerve runs parallel to the internal carotid artery in the cavernous sinus?
abducent nerve
what are the functions of the facial nerve?
- motor innervation to the muscles of facial expression
- taste sensation from the anterior 2/3 of the tongue
- cutaneous sensation for the external ear
- parasympathetic innervation to the nasal glands, lacrimal gland, and submandibular & sublingual salivary glands
which cranial nerve nuclei is the facial nerve associated with?
4
• Trigeminal – the nucleus where facial nerve fibres carrying general sensation terminate
• Rostral end of nucleus solitarius – the nucleus where facial nerve fibres carrying taste sensation terminate
• Facial motor nucleus – the nucleus where lower motor neurones supplying the muscles of facial expression arise
• Superior salivatory nucleus – the nucleus where preganglionic parasympathetic fibres to the lacrimal, nasal, submandibular and sublingual glands arise