Cranial Nerves Origin/Innervation

Question 1

Define: Central Nervous System

Answer 1

Consists of the brain and spinal cord. The CNS interprets sensory information from the PNS.

Question 2

Define: Peripheral Nervous System

Answer 2

Consists of cranial and spinal nerves, ganglia, and sensory receptors. Communicate from sensory receptors to the CNS and back.

Question 3

Define: Gyrus

Answer 3

Elevated ridge of tissue

Question 4

Define: Sulcus

Answer 4

Shallow groove (in between gyri)

Question 5

Define: Fissure

Answer 5

Deep groove (deeper than a sulcus)

Question 6

Define: Rods

Answer 6

Photoreceptor cells that function in dim light and interpret in gray tones.

Question 7

Define: Cones

Answer 7

Photoreceptor cells that are responsible for color vision. They allow high acuity but require high light levels.

Question 8

Optic Nerve

1) Origin
2) Innervation

Answer 8

1) From retina of eye
2) Sensory. Carries afferent impulses associated with vision

Question 9

Oculomotor nerve

1) Origin
2) Innervation

Answer 9

1) Dorsal midbrain
2) Primarily motor. Direct eyeball movement, lens shape, and eyelid. (rectus muscles)

Question 10

Trochlear nerve

1) Origin
2) Innervation

Answer 10

1) Midbrain
2) Primarily motor. Provides somatic fibers to superior oblique muscle that moves eyeball

Question 11

Trigeminal nerve

1) Origin
2) Innervation

Answer 11

1) From face to pons
2) Mixed. Major sensory nerve of face. Also contains motor fibers to innervate muscle of mastication

Question 12

Abducens

1) Origin
2) Innervation

Answer 12

1) Inferior region of pons
2) Carries somatic motor fibers to lateral rectus muscle that moves eyeball

Question 13

Facial nerve

1) Origin
2) Innervation

Answer 13

1) Pons
2) Mixed. Somatic motor fibers to facial expression. Parasympathetic innervation of lacrimal and salivary glands. Sensory fibers from taste receptors in tongue

Question 14

Vestibulocochlear nerve

1) Origin
2) Innervation

Answer 14

1) Internal-ear equilibrium and hearing apparatus through internal acoustic meatus and enter pons
2) Primarily sensory. Sense of equilibrium and hearing

Question 15

Glossopharyngeal nerve

1) Origin
2) Innervation

Answer 15

1) Medulla
2) Mixed. Somatic motor fibers serve pharyngeal muscles. Parasympathetic to salivary glands, Sensory fibers from pharynx, tonsils

Question 16

Vagus nerve

1) Origin
2) Innervation

Answer 16

1) Medulla
2) Mixed. Somatic motor to pharynx and larynx. Parasympathetic to supply heart and smooth muscles of abdominal orgins. Transmits sensory information from viscera

Question 17

Accessory nerve

1) Origin
2) Innervation

Answer 17

1) Medulla and superior aspect of spinal cord
2) Mixed, primarily motor function. Somatic fibers to trapezius muscles and pharynx, larynx

Question 18

Hypoglosseal nerve

1) Origin
2) Innervation

Answer 18

1) Medulla
2) Mixed. Primarily motor. Carries somatic motor fibers to tongue.