Brainstem, cranium, and cranial nerves Flashcards
pons
this is on the ventral surface of the brainstem
-the anterior bulge is the pons
midbrain
- this is rostral to the pons
- this is just inferior to the thalamus
- this surrounds the cerebral aqueduct
- contains the cerebral peduncles
cerebral peduncles
- these are located on the ventral side of the midbrain
- they are two protrusions that appear just superior to the pons
- white matter pathways carry fibers of the corticospinal tract
interpeduncular fossa
this is the space between the cerebral peduncles
medulla oblongata
this is caudal to the pons
- the medulla is continuous with the spinal cord
- contains the pyramids which appear as tube like bulges on the ventral aspect
pyramidal decussation
- where the sulcus between them disappears and the fibers of the track cross
- this is at the junction between the medulla oblongata and the spinal cord
cerebellum
contains two hemispheres
- contains many fine grooves and sulci on the surface running transversely
folia
these are the fine grooves or sulci on the cerebellum that run transversely
CN I
the olfactory nerve
arise in the olfactory epithelium of the nasal cavity and course dorsally to the olfactory bulb inferior to the frontal lobe
travels through the cribiform plate foramina
the olfactory bulbs
these are just inferior to the frontal lobe and they are roustral to the optic chiasm
anything after the olfactory bulb is not the olfactory nerves anymore, those are the olfactory tracts and runs caudally on the ventral aspect of the frontal lobe
CN II
the optic nerve
- the optic nerves begin in the retina
- These nerves course posteriorly and are united in the optic chiasm
- The fibers split again immediately posterior to the optic chiasm and extend posteriorly as the optic tracts
travels through the optic canal
CN III
oculomotor nerve
- can see it emerging from the anterior superior surface of the pons
- emerge in the interpeduncular fossa and innervate 4 of the 6 extraocular muscles
CN IV
trochlear nerve
These are the only nerves to emerge on the brainstem’s dorsal aspect. They travel around the sides of the midbrain and pons to innervate the superior oblique.
You can find these tiny nerves between the lateral rostral pons and the cerebrum.
this passes through the superior orbital fissure
CN V
trigeminal nerves
These large nerves are the only cranial nerves to emerge from the lateral aspect of the pons.
CN VI
abducens nerve
emerge near the midline at the border of the pons and the medulla. They innervate the lateral rectus muscle of the eye.
travels through the superior orbital fissure
CN VII
facial nerve
These emerge from the junction of the pons and medulla lateral to the emergence of the abducens nerves
travels through the internal acoustic meatus
CN VIII
vestibulocochlear nerve
enter the brainstem lateral to (right next to) the facial nerves.
travels through the internal acoustic meatus
CN IX
glossopharyngeal nerve
composed of the most rostral of a series of rootlets that emerge posterior to the olive on the medulla’s lateral aspect
passes through the jugular foramen
CN X
vagus nerve
emerge posterior to the glossopharyngeal nerves in the same series of rootlets
emerges on the lateral sides of the medula oblongata
emerges deep to the hypoglossal nerve
CN XI
spinal accessory nerve
emerges posterior to the vagus nerve.
has lots of tiny extensions from the medulla oblongata where it emerges
has a branch that travels through jugular foramen and the foramen magnum
CN XII
hypoglossal nerve
emerge from the ventral aspect of the caudal medulla as a series of rootlets in the groove just lateral to the pyramids.
this emerges superficial to where the vagus nerve and the glossopharyngeal nerve emerge
what is good to remember about the cranial nerves with only motor functions
emerge medially compared to the other cranial nerves
coronal suture
where the frontal bone meets the two parietal bones
sagittal suture
where the right and left parietal bones meet
lambdoid suture
is between the parietal bones and occipital bone
squamous suture
between the parietal bone and temporal bone on each side.
frontal bone
bone of the forehead
zygomatic bone
makes up the anterior cheek
zygomatic arch
this is where the zygomatic bone and the frontal bone come together to meet each other and makes the cheek bone
nasal bone
forms the superior portion of the nose
maxilla
forms the upper portion of the jeaw and the medial portion of the cheek
mandible
this is the lower jaw bone
mental protuberance
this is the anterior tip of the mandible that forms the chin
temporomandibular joint
this is the articulation between the temporal bone and mandible
they articulate at the condylar process of the mandible
ethmoid bone
best viewed from the internal aspect of the cranium.
a small anterior medial bone located within the anterior cranial fossa
contains the cribriform plate and cribriform foramina
sphenoid bone
best viewed from the internal aspect of the cranium.
this is just posterior to the frontal and ethmoid bones
separates the anterior cranial fossa from the middle cranial fossa
middle cranial fossa
this is mostly made up of the temporal bone and the temporal bone has a ridge that separates the middle cranial fossa from the posterior cranial fossa
cribriform foramina
in the cribriform plate
the olfactory nerve passes through
optic canal
the optic nerves and the ophthalmic arteries pass through
superior orbital fissure
CN III,CN IV, CN V, CN VI all pass through
foramen ovale
-CN V passes through
carotid canal
the internal carotid artery passes through
- this is in the temporal bone
foramen magnum
Medulla oblongata and meninges, vertebral arteries, CN XI (branch)
jugular foramen
CN IX, X, and XI (branch); internal jugular vein
hypoglossal canal
Hypoglossal nerve (CN XII) pass through - this is in the carotid canal
internal acoustic meatus
CN VII and CN VIII pass through
stylomastoid foramen
Branch of CN VII that innervates the facial muscles
This foramen is visible between the mastoid process and the styloid process of the temporal bone.
occipital condyles
articulate with the atlas of the vertebral column.
temporal bone
- these are laterally located near the ear
- contains the mastoid process and styloid process
condylar process
a posterior structure on the mandible that articulates with the temporal bone
coronoid process
The flat portion protruding up just anterior to the condylar process of the mandible
lacrimal bone
situated at the front part of the medial wall of the orbit
palatine bone
a paired bone located between the maxillae and the pterygoid process of the sphenoid bone
this is making up the posterior roof of the mouth
vomer
one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones.
