Human Anatomy and Physiology : Peripheral Nervous System

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #3 : Cranial Nerves

What is the function of cranial nerve III?

Possible Answers:

Controls the muscle that makes the eye look to the side

Carries visual information from the back of the eyes to the brain

Controls most of the muscles that move the eyeball

Controls a muscle that helps rotate the eye down and out

Correct answer:

Controls most of the muscles that move the eyeball

Explanation:

Cranial nerve III is the oculomotor nerve, which controls most of the muscles needed for eye movement. Also, this nerve controls the ciliary muscle and is responsible for pupillary constriction via parasympathetic innervation. The cranial nerve that makes the eye look to the side is the abducens nerve or cranial nerve VI. The muscle that helps roate the eye down and out is the trochlear nerve or cranial nerve IV. The nerve that carries visual information from the back of the eyeballs to the brain is the optic nerve or cranial nerve II.

Example Question #11 : Cranial Nerves

Which nerve passes through the mandibular foramen?

Possible Answers:

Vagus nerve

Inferior alveolar nerve

Opthalmic nerve

Optic nerve

Linguinal nerve

Correct answer:

Inferior alveolar nerve

Explanation:

The inferior alveolar nerve passes through the mandibular foramen. It has motor and sensory components. It serves to give the lower face and jaw sensation and is also responsible for stimulating the muscles for movement of the jaw.

Example Question #12 : Cranial Nerves

Which branch of the trigeminal nerve provides sensation to the upper lip?

Possible Answers:

Mandibular nerve 

Cervical nerve

Ophthalmic nerve 

Buccal nerve

Maxillary nerve 

Correct answer:

Maxillary nerve 

Explanation:

The trigeminal nerve (cranial nerve V) is responsible for facial sensation and motor functions, such as biting and chewing. The trigeminal nerve has three major branches (hence: tri-): the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3). The opthalmic and maxillary nerves are purely sensory, and the mandibular nerve has both sensory and motor functions. VI provides sensation to the forehead, upper eyelids, and the bridge and tip of the nose. V2 provides sensation lateral to the eyelids, the cheeks, nostrils, and upper lip. V3 provides sensation to the lower lip, chin, skin over the jaw, and pre-auricular area.

Example Question #13 : Cranial Nerves

Which cranial nerve(s) supply taste sensation to the tongue?

Possible Answers:

VII and IX

IX only

IX and X

VII and X

VII only

Correct answer:

VII and IX

Explanation:

Cranial nerves VII and IX supply taste sensation to the tongue. Cranal nerve VII (facial) supplies taste to the anterior two-thirds of the tongue and cranial nerve IX (glossopharyngeal) supplies somatosensation and taste to the posterior one-third of the tongue.

Example Question #14 : Cranial Nerves

The maxillary branch of cranial nerve V (trigeminal) has all of the following branches except __________.

Possible Answers:

infraorbital

zygomaticofacial

zygomaticotemporal

All of these are branches of the maxillary branch of the trigeminal nerve.

auriculotemporal

Correct answer:

auriculotemporal

Explanation:

Cranial nerve V (trigeminal) has 3 branches: ophthalmic, maxillary, and mandibular. Each of these branches have their own branches. The maxillary branch has 3 sub-branches named zygomaticofacial, zygomaticotemporal, and infraorbital. The mandibular branch has 3 sub-branches named auriculotemporal, buccal, and mental. The ophthamic branch has 5 sub-branches named supraorbital, supratrochlear, infraorbital, lacrimal, and external nasal.

Example Question #15 : Cranial Nerves

Which cranial nerve supplies somatic afferent sensation from the mucosa of the middle ear and visceral afferent sensation from the carotid body and carotid sinus?

Possible Answers:

VII (facial)

V (trigeminal)

XI (accessory)

IX (glossopharyngeal)

X (vagus)

Correct answer:

IX (glossopharyngeal)

Explanation:

The glossopharyngeal cranial nerve functions in supplying visceral and somatic afferent sensation from the carotid body, carotid sinus, posterior one-third of the tongue, palatine tonsils, oropharynx, mucosa of the middle ear, and pharyngotympanic tube. It also supplies taste from the posterior one-third of the tongue and visceral efferent function to parotid salivary gland.

Example Question #16 : Cranial Nerves

Which of the following cranial nerves have both sensory and motor functions?

Possible Answers:

V, VI, IX, X

IV, V, VIII, X

V, VII, IX, X

V, VII, IX, XII

V, VII, X, XI

Correct answer:

V, VII, IX, X

Explanation:

The four cranial nerves the have sensory and motor function are cranial nerve V (trigeminal), VII (facial), IX (glossopharyngeal), and X (vagus).

Example Question #12 : Identifying Cranial Nerve Function

Which cranial nerve is responsible for controlling the muscles that move the tongue?

Possible Answers:

Optic

Trochlear

Abducens 

Vestibulocochlear 

Hypoglossal 

Correct answer:

Hypoglossal 

Explanation:

Cranial nerve XII, the hypoglossal nerve, is responsible for controlling muscles that move the tongue. The vestibulocochlear nerve is responsible for sound and balance. The abducens and trochlear are responsible for controlling extraocular muscles. The optic nerve conveys information from the photoreceptor cells of the retina of the eye. 

Example Question #13 : Identifying Cranial Nerve Function

What cranial nerves are responsible for taste sensation?

Possible Answers:

7 only

5 only

12 only

7 and 9

7, 9, and 10

Correct answer:

7, 9, and 10

Explanation:

Taste is unique and is controlled by the facial, glossopharyngeal, and vagus cranial nerves. This can be further explained in which facial controls the anterior two-thirds of the tongue, glossopharyngeal controls the posterior one-third, and vagus innervates taste in the pharynx.

Example Question #14 : Cranial Nerves

Which of the following cranial nerves carry preganglionic parasympathetic motor fibers?

Possible Answers:

CN III

CN IX

None of these

All options (CN III, VII, and IX)

CN VII

Correct answer:

All options (CN III, VII, and IX)

Explanation:

Parasympathetic nerves are autonomic branches of the peripheral nervous system (PNS). These arise from some cranial nerves (that participate in cranial nuclei), the vagus nerve (although a cranial nerve, these fibers doe not participate in cranial ganglia and their parasympathetic action is directed to the thoracic cavity), and pelvic splanchnic efferent preganglionic nerve bodies. 

The preganglionic parasympathetic nerves of CN III, CN VII, and CN IX arise from nuclei in the CNS. These fibers go on to synapse at one of four parasympathetic ganglia: ciliary, pterygopalatine, submandibular, or otic and provide parasympathetic function to the head and neck.

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