Embryology/Anatomy

Created by

Jessica Jardine

Cards (14)

What parts of the ear are ectoderm, mesoderm & endoderm?
Ectoderm -> external acoustic meatus & bones of inner ear
Mesoderm -> otic capsule (neurons inside are ectodermal)
Endoderm -> Eustachian tube
What does the otic vesicle form?
Membranous labyrinth
What does cochleovestibular ganglion form?
Spiral & vestibular ganglia (neurons of the inner ear)
What is the circuitry of the facial nerve?
Originates in the pontomedullary region → passes through the internal auditory meatus → exits through stylomastoid foramen
Facial nerve loops around the abducens nucleus
What are the functions of the facial nerve?
Function:
general somatic afferent = innervates skin behind ear
special visceral afferent = taste to anterior 2/3 of tongue
general visceral efferent = parasympathetic innervation to lacrimal, sublingual & submandibular glands
special visceral efferent = innervates muscles of facial expression
What are the 3 sensory nuclei of the trigeminal nerve?
Mesencephalic = proprioception
Principal = light tough & discrimination
Spinal = pain, temp & crude touch
What are the 3 divisions of the trigeminal nerve?
Ophthalmic
Maxillary
Mandibular
What is the function of V1 of the trigeminal nerve?
Sensation = above lower eyelid
Where does the ophthalmic branch of the trigeminal nerve exit the skull?
Superior orbital fissure
What is the function of V2 of the trigeminal nerve?
Sensation = lower eyelid to upper lip
Where does the maxillary branch of the trigeminal nerve exit the skull?
Foramen rotundum
What is the function of V3 of the trigeminal nerve?
Sensation = below upper lip
Motor = muscles of mastication
Where does the mandibular branch of the trigeminal nerve exit the skull?
Foramen ovale
How is the trigeminal nerve involved in facial pain?
Nociceptive signals travel from trigeminal system → decussate → neurons project to ventral posterior medial nucleus of the thalamus → thalamocortical neurons project to somatosensory cortex