Head and Neck Flashcards
What are the borders of the anterior cranial fossae
anterior border = frontal bone
posterior border = lesser wing of sphenoid bone
what are the borders of the middle cranial fossae
anterior = lesser wing of sphenoid bone lateral = squamous part of temporal bone posterior = dorm sella posterior = patris part of temporal bone
what are the boundaries of the posterior cranial fossae
anterior = dorm sella
petrous part of temporal antrolaterally
occipital posteriorly
what are the functions of cranial nerves
• Sensory (afferent) fibres transmitting general sensation
• Sensory fibres transmitting sensation from organs
• Sensory fibres transmitting unique sensations such as
taste and smell
• Motor (efferent) fibres to striated muscle
• Motor fibres that are involved with the innervation of
glands and smooth muscle
name the 12 cranial nerves
CN I = Olfactory nerve CN II = Optic n CN III = Oculomotor n CN IV = Trochlear n CN V = Trigeminal n - Ophthalmic division (CNVa) - Maxillary division (CNVb) - Mandibular division (CNVc) CN VI = Abducent n CN VII = facial n VIII = Vestibulocochlear n CN IX = Glossopharyngeal n CN X = Vagus n CN XI = Accessory n CN XII = Hypoglossal n
Describe the location of the cranial nerve nuclei
Each of the cranial nerves has a collection of cell bodies known as cranial nerve nuclei
The cranial nerve nuclei of CNI are located within the olfactory epithelium in the nasal cavity
The cranial nerve nuclei of CNII are located within the retina
The cranial nerve nuclei of CNIII – CNXII are located within the brainstem
what nerves travel through the cavernous sinuses
oculomotor nerve - CN III Trochlear nerve CN IV Abducent nerve CN VI Ophthalmic nerve CN Va Maxillary nerve CN Vb
what nerve passes through the cribriform foramina
CN I - olfactory n
what nerve passes through the optic canal
CN II - optic nerve
what nerves pass through the superior orbital fissure
CN III - oculomotor n
CN IV - trochlear n
CN Va - ophthalmic n
CN VI - abducent n
what nerve passes through the foramen rotundum
CN Vb - maxillary n
what nerve passes through the foramen ovale
CN Vc - mandibular n
what nerves pass through the internal acoustic meatus
CN VII - facial n
CN VIII - vestibulocochlear n
what nerves pass through the jugular foramen
CN IX - glossopharyngeal n
CN X - vagus n
CN XI - spinal accessory n
what nerve passes through the hypoglossal canal
CN XII - hypoglossal
name the roof, flood, medial and lateral walls of the orbit
roof = frontal bone medial = maxilla, lacrimal and ethmoid and small part of lesser wing of sphenoid - thinnest of all of the walls lateral = zygomatic and greater wing of sphenoid floor = zygomatic and maxilla
what nerves pass through the superior orbital fissure
oculomotor nerve (CN III), trochlear nerve (CN IV), and abducent nerve (CN VI).
Levator palpebrae superioris: origin insertion innervation action
lesser wing of sphenoid bone
skin of upper eyelid
oculomotor nerve - CN III
elevates superior eyelid
Superior oblique: origin insertion innervation action
body of sphenoid
tendon passes through a fibrous ring or trochlea, changes its direction, and inserts into sclera deep to superior rectus muscle
trochlear nerve - CN IV
abducts depresses and medially rotates eyeball
Inferior oblique: origin insertion innervation action
anterior part of floor of orbit
sclera deep to lateral rectus muscle
oculomotor nerve - CN III
abducts elevates and laterally rotates the eyeball
Superior rectus origin insertion innervation action
common tendinous ring
sclera just posterior to corneaoscleral junction
oculomotor nerve CN III
elevates adducts and rotates eyeball medially
Inferior rectus: origin insertion innervation action
common tendinous ring
sclera just posterior to corneoscleral junction
oculomotor nerve CN III
depresses, adducts and rotates eyeball laterally
Medial rectus: origin insertion innervation action
Common tendinous ring
Sclera just posterior to corneoscleral junction
oculomotor nerve CN III
adducts eyeball
Lateral rectus: origin insertion innervation action
Common tendinous ring
Sclera just posterior to corneoscleral junction
abducent nerve CN VI
Abducts eyeball
describe the innervation of the extra ocular muscles
LR6
SO4
REM3
Lateral rectus = 6th = abducent
Superior oblique = 4th = trochlear
Remainder = 3rd = oculomotor
what are the branches of the facial nerve (CNVII)
Branches of CNVII supplying mm of facial expression:
- Temporal
- Zygomatic
- Buccal
- Mandibular
- Cervical