Gross Anatomy of Brain/Cranial Nerves

Question 1

What are the 3 main regions of the brain?

Answer 1

Cerebrum
Cerebellum
Brainstem

Question 2

What lobes contribute to the cerebrum?

Answer 2

Frontal
Parietal
Occipital
Temporal

Question 3

What are 3 regions of the brainstem?

Answer 3

Midbrain
Pons
Medulla Oblongata

Question 4

What does the central sulcus separate?

Answer 4

Frontal lobes and parietal lobes

Question 5

Where is the lateral sulcus?

Answer 5

Inferior to frontal and parietal lobes

Question 6

Which region is continuous with the spinal cord?

Answer 6

Medulla Oblongata

Question 7

What does the longitudinal cerebral fissure separate?

Answer 7

The 2 cerebral hemispheres

Question 8

What is the clivus?

Answer 8

Bony landmark anterior to foramen magnum

Question 9

Where does the midbrain lie?

Answer 9

Junction of middle and posterior cranial fossae

Question 10

Where does the pons lie?

Answer 10

Anterior aspect of posterior cranial fossa

Question 11

Where does the medulla oblongata lie?

Answer 11

Posterior cranial fossa; continuous with spinal cord

Question 12

What is CN I called, and what is its role?

Answer 12

Olfactory Nerve

Sensory - Smell

Question 13

What is CN II called, and what is its role?

Answer 13

Optic nerve

Sensory - Vision

Question 14

What is CN III called, and what is its role?

Answer 14

Oculomotor nerve
Motor - Extrinsic muscles of eye (SR, IR, MR, IO, LP)
Motor - Ciliary muscles and sphincter pupillae

Question 15

What is CN IV called, and what is its role?

Answer 15

Trochlear nerve

Motor - Extrinsic muscle of eye (SO)

Question 16

What is CN V called, and what is its role?

Answer 16

Trigeminal nerve
Sensory - face; oral, nasal and sinus mucosa; teeth; anterior 2/3 of tongue
Motor - muscles of mastication (temporalis, masseter, medial/lateral pterygoid muscles, mylohyoid, anterior belly of digastric, tensor veli palatini, tensor tympani)

Question 17

What is CN VI called, and what is its role?

Answer 17

Abducent nerve

Motor - Extrinsic muscle of eye (LR)

Question 18

Where are the olfactory bulb/tract located?

Answer 18

In contact with inferior/orbital surface of frontal lobe of cerebrum

Question 19

How is the nasal cavity divided?

Answer 19

Superior 1/3 = olfactory area

Inferior 2/3 = respiratory area

Question 20

Where do olfactory nerves travel?

Answer 20

Pass through tiny foramina in cribiform plate of ethmoid bone

Question 21

Where does CN II exit the orbit?

Answer 21

Via optic canal (sphenoid in lesser wing and body) to enter middle cranial fossa

Question 22

How does CN II travel?

Answer 22

2 optic nerves join forming the optic chiasm before dividing into two optic tracts

Question 23

Where does CN III emerge?

Answer 23

Midbrain

Question 24

Where does the CN III travel?

Answer 24

Through cavernous sinus, and exits cranial cavity via superior orbital fissure

Question 25

Which muscles regulate pupil size? What systems are they innervated by?

Answer 25

``` Pupillary sphincter (parasympathetic) Pupillary dilator (sympathetic) ```

Question 26

What type of information does the oculomotor nerve carry?

Answer 26

Parasympathetic information

Question 27

How does the oculomotor nerve contribute to intra-ocular muscles?

Answer 27

``` Sphincter pupillae (constriction of pupil) Ciliary muscle (accomodation, or rounded lens, for near vision) ```

Question 28

Where does the CN IV emerge from the brain?

Answer 28

Posterior surface of midbrain

Question 29

How does CN IV travel?

Answer 29

Passes anteriorly around brainstem (specifically, pons), through cavernous sinus, exits cranial cavity and enters orbit via superior orbital fissure

Question 30

Where does CN VI emerge from the brain?

Answer 30

From brainstem between pons and medulla

Question 31

Where does CN VI travel?

Answer 31

Through cavernous sinus, exits cranial cavity and enters orbit via superior orbital fissure

Question 32

Where does the trigeminal nerve emerge from the brain?

Answer 32

Lateral aspect of pons - large sensory root; small motor root

Question 33

What are the three branches of the trigeminal nerve?

Answer 33

``` Ophthalmic nerve (CN V1) Maxillary nerve (CN V2) Mandibular nerve (CN V3) ```

Question 34

Where does the ophthalmic nerve exit the cranial cavity?

Answer 34

Superior orbital fissure

Question 35

Where does the maxillary nerve exit the cranial cavity?

Answer 35

Foramen rotundum

Question 36

Where does the mandibular nerve exit the cranial cavity?

Answer 36

Foramen ovale

Question 37

Which cranial nerves pass through the superior orbital fissure?

Answer 37

Oculomotor nerve Trochlear nerve Trigeminal nerve (ophthalmic branch) Abducent nerve