Cranial Fossa And Cranial Nerves

Question 1

What are the fossae within the skull

Answer 1

Anterior, middle and posterior

Question 2

What is within the anterior fossa

Answer 2

Cribriform plate, crista galli and optic canal

Question 3

What is within the middle fossa

Answer 3

Foramen rotundum, foramen ovale, foramen lacerum and foramen spinosum

Question 4

What does the carotid canal contain

Answer 4

The internal carotid artery

Question 5

What does the foramen spinosum contain

Answer 5

The middle meningeal artery

Question 6

What does the posterior fossa contain

Answer 6

The groove for the sigmoid dural sinus, jugular foramen, hypoglossal canal and the foramen magnum

Question 7

What are the cranial nerves

Answer 7

Olfactory, optic, occulomotor, trochlear, trigeminal, abducens, facial, vestibulocohlear, glossopharyngeal, vagus, accessory and hypoglossal

Question 8

CN 1 Olfactory

Answer 8

Outgrowth of the telencephalon

Only sensory system that is not relayed through the thalamus

Question 9

Path of the olfactory

Answer 9

The olfactory mucosa goes through the cribriform plate to synapse in the olfactory bulb

Question 10

Where does the olfactory nerve run from/to

Answer 10

The olfactory tracts to the prepiriform area of amygdala

Question 11

What is the prepiriform area of amygdala

Answer 11

Primary olfactory cortex

Question 12

CN II Optic

Answer 12

Extension of the diencephalon

Question 13

Where does the optic nerve run from/to

Answer 13

The retina through the optic canal, then forms a chiasm and joins the optic tract

Question 14

What happens to the fibres of the optic nerve

Answer 14

90% - go to the lateral geniculate body of the thalamus and onto the striate area
10% - go to the medial root (non-genicular) to unconcious regulation

Question 15

CN III Oculomotor

Answer 15

Come from the midbrain and enters the orbit

Provides somatic motor and parasympathetic innervation

Question 16

What does the oculomotor nerve provide motor innervation to

Answer 16

Inferior oblique, superior rectus, middle rectus, inferior rectus and levator palpabrae

Question 17

What does the occulomotor provide parasympathetic innervation to

Answer 17

Sphincter pupillae and ciliary body

Question 18

What does the superior division of the oculomotor supply

Answer 18

Levator palpabrae and superior rectus

Question 19

CN IV Trochlear

Answer 19

Comes from the midbrain
Only cranial nerve in which the fibres cross to the opposite side and the only cranial nerve from the posterior surface of the midbrain

Question 20

Where does the oculomotor run from/to

Answer 20

The lateral wall of the cavernosous dural sinus and travels through the annular ring

Question 21

Where does the trochlear run from/to

Answer 21

The lateral wall of the cavernous dural sinus and sits outside the annular ring

Question 22

CN V Trigeminal

Answer 22

Originates from the pons

Forms a ganglion and divides into three divisions

Question 23

What are the three divisions of the trigeminal

Answer 23

CN V1 - ophthalmic branch
CN V2 - maxillary branch
CN V3 - trigeminal branch

Question 24

What does the ophthalmic branch enter

Answer 24

The orbit through the superior orbital fissue

Question 25

Where does the maxillary enter

Answer 25

The pytergopalatine fossa through the foramen rotundum

Question 26

Where does the trigeminal branch travel

Answer 26

Through the foramen ovale to the inferior surface of the base of the skull

Question 27

What nerves allow the passage of parasympathetic fibres from other cranial nerves

Answer 27

The lacrimal, zygomatic, lingual and auriculotemporal

Question 28

What does CN V1 provide

Answer 28

General sensory innervation for the eye, lacrimal gland, eyebrow, skin of the forehead and nose

Question 29

Where does CN V1 run

Answer 29

In the lateral wall of the cavernous dural sinus

Question 30

What does CN V2 provide

Answer 30

General sensory innervation to the skin of the cheek, lower lid, upper jaw and teeth, side of nose and the mucosa of the mouth

Question 31

Where does CN V2 run

Answer 31

In the lateral wall of the cavernous dural venous sinus

Question 32

What CN V3 provide

Answer 32

Sensory innervation to the ear canal, parotid gland, lower jaw and teeth Motor innervation to the muscles of mastication, anterior belly of digastric, mylohyoid, tensor tympani and veli tensor palatine

Question 33

CN VI Abducens

Answer 33

Originates from the pons | Long extradural pathway

Question 34

Where does the abducens run from/to

Answer 34

It passes through the superior orbital fissue, the cavernous dural venous sinus and annular ring and enters the eye

Question 35

What does abducens provide

Answer 35

Motor innervation to lateral rectus

Question 36

CN VII Facial

Answer 36

Originates from the pons | Passes through the acoustic meatus

Question 37

Where does abducens run from/to

Answer 37

The pons to the temporal bone

Question 38

What are the branches of the abducens

Answer 38

Greater petrosal, stapedial and chorda tympani

Question 39

What are the facial muscle branches from abducens

Answer 39

Temporal, zygomatic, buccal, mandibular and cervical posterior auricular

Question 40

What does abducens provide

Answer 40

Motor innervation to the muscles of facial expression, stapedius, stylohyoid and the posterior belly of digastric

Question 41

Where do the nerves that innervates the muscles of facial expression leave through

Answer 41

The stylomastoid foramen

Question 42

CN VIII Vestibulocochlear

Answer 42

Special somatic efferent nerve | From the vestibule apparatus and auditory apparatus to the pons/medulla

Question 43

What does the vestibular nerve provide

Answer 43

Innervation to the maculae of the utricle and saccule, and the cristae of ampulla of the semicircular ducts

Question 44

What is the maculae of the saccule and utricle sensitive to

Answer 44

Linear acceleration and the pull of gravity relative to the position of the head

Question 45

What is the cristae of ampulla in the semicircular ducts sensitive to

Answer 45

Rotational acceeration

Question 46

What does the cochlear nerve provide

Answer 46

Innervation to the special organs. for the sense of hearing

Question 47

CN XI Glossopharyngeal

Answer 47

Originates from the medulla oblongata | Passes through the jugular foramen

Question 48

What does the glossopharyngeal provide

Answer 48

Parasympathetic innervation to the parotid, buccal and labial glands Sensation of taste to the posterior 1/3rd of the tongue Motor innervation to the pharyngeal plexus and stylopharyngeus Sensory innervation to the posterior 1/3rd of the tongue, soft palate, pharynx, tympanic cavity and membrane, pharyngotympanic tube, external ear and auditory canal

Question 49

CN X Vagus

Answer 49

Originates from the medulla oblongata | Passes through the jugular foramen

Question 50

Distribution of the vagus nerve

Answer 50

Cranial, cervical, thoracic and abdominal

Question 51

What does the vagus provide

Answer 51

Motor innervation to the pharyngeal plexus, soft palate and larynx Parasympathetic innervation to the thoracic and abdominal viscera Sensory innervation to the dura in the post-cranial fossa, ear, external auditory canal, lower pharynx, laryngeal mucosa, thoracic and abdominal viscera

Question 52

What does the vagus provide in the aortic arch and para-aortic body

Answer 52

Aortic arch - pressure receptors | Para-aortic body - chemoreceptors

Question 53

CN XI Accessory

Answer 53

Originates from the spinal cord | Enters the foramen magnum and the passes through the jugular foramen

Question 54

What does the accessory nerve provide

Answer 54

Motor innervation to trapezius and sternocleidomastoid

Question 55

CN XII Hypoglossal

Answer 55

Originates from the medulla oblongata, anterior to the olive | Passes through the hypoglossal canal

Question 56

What does the hypoglossal nerve provide

Answer 56

Motor innervation to all the intrinsic and extrinsic muscle of the tongue bar palatoglossus