Cranial Nerves I Flashcards
They give rise to the structures of the head and neck.
The branchial arches aka pharyngeal arches
Define the branchial arches
Series of extremely visible anterior tissue bands that lie under the early brain in embryologic development.
How many arches form during development of a human and how many of those are visible on the embryo?
5; 4
What to do brachial arches give rise to?
- Face
- Tongue
- Lips
- Jaws
- Palate
- Pharynx
- Neck CNs
- Glands
CN V name and artery
Trigeminal, maxillary artery
Trigeminal artery skeletal structures:
Mandible, maxilla, malleus, incus.
CN V muscles:
Muscles of mastication, mylohyoid, anterior belly of digasteric.
Facial nerve number and artery:
CN VII, Stapedial artery.
These skeletal structures are innervated by the facial nerve:
Stapes, styloid process, upper part of body of hyoid.
Facial nerve (VII) muscles:
Muscles of facial expression, stapedius, stylohyoid, posterior belly of digastric.
Common carotid & internal carotid arteries feed this CN:
Glossopharyngeal (IX)
CN IX skeletal structures:
Lower part of body of hyoid.
CN IX name:
Glossopharyngeal
Vagus (X) nerve arteries:
Part of aortic arch and part of R subclavian arteries.
Also part of the L and R pulmonary arteries.
Thyroid and cricoid cartilages are the skeletal structures of the CN:
Vegus (X)
CN II
Optic Nerve
Optic Nerve is CN __
II
Optic nerve is surrounded by
meninges and CSF
The optic nerve exits the cranial cavity via the
optic canal
The optic nerve is composed of what?
axons of ganglion cells that are located in the retina
Nerves from the optic canal cross at the _____ which is located directly above the _____
Optic chiasm, pituitary gland
Nasal retinal fibers will _________, while temporal retinal fibers will ______
cross into the opposite optic tract, remain uncrossed
(Ant/Post) to the chiasm, the continuation of the visual signal occurs via the ______, which relay information to the _______ and ultimately the ______
optic tracts, lateral geniculate nucleus (LGN), visual cortex
The optic nerve contains these kinds of fibers
Special Afferent (SA) fibers for vision
The optic nerve is surrounded by what kind of nerves?
Ophthalmic nerves
Optic nerve enters the globe from the _____ surface
Posterior
CN III
Oculomotor
Oculomotor CN ___
III
The nuclei of Oculomotor nerve are located where?
in the midbrain
Oculomotor nerve contains what type of nerves?
Motor GE and parasympathetic fibers (VE)
The oculomotor nerve exits the cranial cavity through through
the superior orbital fissure
_______ of the provide motor innervation to extraocular muscles
General Efferent (GE)
Name the muscles that are innervated by general efferent fibers of oculomotor nerves
Superior rectus, inferior rectus, medial rectus, inferior oblique, levator palpebrae superioris
______ fibers provide innervation to smooth muscles of the eye
Visceral Efferent (VE)
Visceral efferent fibers of the oculomotor nerve are (sympathetic/parasympathetic)
parasympathetic
Superior rectus, inferior rectus, medial rectus, inferior oblique, levator palpebrae superioris are innervated by what type of fibers?
General efferent
Iris sphincter, ciliary muscles are innervated by what kind of fibers?
Visceral Efferent
Name the muscles innervated by the oculomotor nerve
Superior, inferior, medial rectus
Inferior oblique and levator palpebrae superioris, irsi sphincter and ciliary muscle
Trauma to this region can affect your sense of smell
cribriform plate
Fracture of the cribriform plate can also lead to
cerebrospinal fluid rhinorrhea (its like diarrhea of csf through the nose)
Which nerve is not a true nerve?
Olfactory nerve (CN I)
CN I is surrounded by
CSF and meninges
CN I exits the cranial cavity through
perforations in the cribriform plate of the ethmoid bone
CN I contains what kind of fibers?
Special afferent (SA) fibers
Anosmia is
absent olfaction
