Cranial Nerves 1

Question 1

Cranial nerves arise from the ______ and ______________ inside the cranial cavity and pass through various __________ in the bones of the cranium to supply various structures

Answer 1

brain, brainstem, foramina

Question 2

General location and origin of fibres

Answer 2

4 above the pons
4 in the pons
4 below the pons

Question 3

Cranial nerve fibres with efferent functions arise from?

Answer 3

Motor nuclei deep within the brain stem; homologous to the anterior horn cells of the spinal cord

Question 4

Cranial nerve fibres with afferent functions arise from?

Answer 4

Their cells have an origin outside of the brainstem, typically in ganglia that are homologous with the dorsal root ganglia

Question 5

____ modalities can be carried by a cranial nerve

Answer 5

7

Question 6

Parasympathetic Nerves

Answer 6

3, 7, 10, 9

Question 7

CN I : Olfactory

Answer 7

Sensory nerve. Contains axons that conduct impulses for olfaction, the sense of smell

Question 8

Olfactory uses _____________ neurons

Answer 8

Bi-polar

Question 9

Anosmia

Answer 9

Without smell

Question 10

Parosmia

Answer 10

Abnormal smell

Question 11

Causes of smell abnormalities

Answer 11

Head trauma, viral infections, intracranial lesions, degenerative disease, tobacco, cocaine use, covid

Question 12

CN II : Optic

Answer 12

Posterior to the eyeball, two optic nerves emerge

Question 13

Axons of all ganglion cells in the retina of each eye join to form an _______ _________, which passes through the _____ ___________

Answer 13

Optic nerve, optic foramen

Question 14

Pathway of Light into the eye

Answer 14

Retina, optic nerve, chiasm, tract, synpase at the lateral geniculate nucleus, loops of meyer - thorugh internal capsule, calcarine sulcus in occipital lobe

Question 15

BA Primary Visual Cortex

Answer 15

BA 17

Question 16

Superior Brachium

Answer 16

Passes from the superior colliculus to the lateral geniculate body and the optic tract

Question 17

Inferior Brachium

Answer 17

Connects the inferior colliculus to the medial geniculate body

Question 18

Corneal Reflections

Answer 18

Should be visible slightly nasal to the pupils; asymmetry suggest extra ocular muscle pathology

Question 19

CN III : Oculomotor

Answer 19

Located in the midbrain, exists the brainstem ventrally in the interpeduncular fossa. Divides into superior and inferior branches - both pass through the superior orbital fissure

Question 20

Oculomotor - Inferior brach supply

Answer 20

Medial rectus, inferior rectus, inferior oblique muscles

Question 21

Oculomotor - Inferior branch also provides _______________ innervation to intrinsic eye muscles, which are smooth muscles

Answer 21

Parasympathetic

Question 22

Parasympathetic eye muscles

Answer 22

Ciliary muscles, circular muscles

Question 23

What is the relay centre of the autonomic nervous system?

Answer 23

Goes from culomotor nucleus in the midbrain to the ciliary ganglion - edinger-westphal nucleus

Question 24

Pupillary constriction is mediated through which cranial nerve?

Answer 24

CN III Oculomotor

Question 25

Extra Ocular Muscle Movement

Answer 25

Inward, outward, upwards & downward gaze, adduction

Question 26

Pupillary Reflex

Answer 26

Optic nerve, chiasma, occulomotor nerve, ciliary ganglion, ciliary muscle reflex

Question 27

Accommodation Reflex

Answer 27

As eyes converge, the pupils should constrict in order to keep focus

Question 28

Elevates Upper Eyelid

Answer 28

Levator palpebrae superiorus

Question 29

CN IV : Trochlear Nerve

Answer 29

Innervation to superior oblique, smallest cranial nerve, arises from posterior brainstem

Question 30

Trochlear nerve passes through the ______ ______ ________ of orbit

Answer 30

Superior orbital fissure