Exam 3 Ch.18-19

Question 1

Identify and name the cranial nerves responsible for blinking and movement of the eyeball. Indicate the function of each cranial nerve identified.

Answer 1

CNIII(oculomotor): Parasympathetic function to the pupil and ciliary muscle for visual accommodation.
CNIV(trochlear): Sends motor output information to the superior oblique muscle
CNVI(abducens): Sends motor output information to the lateral rectus muscle

Question 2

What cranial nerve is associated with the organs found in the ventral body cavity? What part of the skull does this nerve pass through?

Answer 2

CN X(vagus) passes through jugular foramen

Question 3

What are the cranial nerves associated with the special sense organs in the head? What is the function and passageway of each nerve?

Answer 3

CNI(olfactory): Send sensory information about olfaction (smell) towards the brain. Passageway: cribriform plate
CNII(optic): Sends sensory information about light (vision) from the eye toward the brain. Passageway: optic canal
CNVIII(vestibulocochlear): sensory receptors interpret balance and position of the head. Passageway: internal acoustic meatus

Question 4

Why are CN VII and CN VIII found in the same skull opening? What is the opening?

Answer 4

Internal acoustic meatus.

Question 5

List all the 4 nerves that pass through the superior orbital fissure of sphenoid bone.

Answer 5

CNIII(oculomotor)
CNIV(trochlear)
CNV(trigeminal)
CNVI(abducens)

Question 6

List all the structures that pass through the jugular foramen.

Answer 6

CNIX(glossopharyngeal)
CNX(vagus)
CNXI(accessory)

Question 7

What cranial nerve(s) serve the tongue for the sensation of taste?

Answer 7

CNVII(facial)
CNIX(glossopharyngeal)
CNX(vagus)

Question 8

What muscles are needed for swallowing? What cranial nerve(s) innervate these muscles?

Answer 8

CNIX(glossopharyngeal): stylopharyngeus muscle which elevates the pharynx (throat) during swallowing.
CNX(vagus): pharyngeal constrictor muscles (superior, middle, and inferior) constrict the pharynx during swallowing
CNXIII(hypoglossal)

Question 9

What muscles are needed for chewing? What nerves innervate the muscles needed for chewing?

Answer 9

CNV3(mandibular): massetter, temporalis, lateral/medial pterygoid
CNXIII(hypoglossal): genioglossus, hyoglossus, styloglossus

Question 10

What muscle(s) help you pucker your lips for a kiss? Sucking on a straw?

Answer 10

Orbicularis oris & buccinator

Question 11

Why isn’t the brain a long, smooth tube?

Answer 11

Limited room during development results in dorsal hollow nerve tube bending.

Question 12

What are the two tubes found in the neck? What is their location to each other and purpose? What embryonic tissue is associated with each tube?

Answer 12

Pharynx: connects the nasal and oral cavities. For food & air derived from: mesoderm
• It is wrapped in pharyngeal constrictors
Esophagus: connects the oral cavity to the stomach.
• It is derived from endoderm.

Question 13

Where is each pharyngeal constrictor located? What nerve is used to contract the pharyngeal constrictor muscles during swallowing?

Answer 13

right and left sides of the oral cavity and larynx, then wrap dorsally, or “behind” the gut tube.
Innervated by CN – X, Vagus nerve.

Question 14

Discuss the three (3) stages of deglutition. What structures and nerves are needed for each stage?

Answer 14

Buccal:
• Muscles of mastication (CN V3) and teeth are used to grind the food.
• What are these muscles?
• Salivary glands (CN VII & IX) produce saliva to lubricate food and break down carbohydrates (salivary amylase).
• Tongue muscles (CN XII) press food against the hard palate and towards the pharynx.
• What are these muscles?
• Softpalateelevates(CNX)to seal off the nasal cavity.
Pharyngeal:
• Hyoid and larynx muscles contract and the epiglottis covers the larynx.
• What muscles will elevate the hyoid? Depress the hyoid?
• Superior pharyngeal constrictors contract (CN X) to pull food
into the pharynx.
• Middle and inferior pharyngeal constrictors contract (CN X) moving food toward the esophagus.

Question 15

How does the epiglottis help move food into the esophagus during swallowing?

Answer 15

closes airway during swallowing. It’s the superior portion of the larynx

Question 16

What are the blood vessels and nerves associated with the neck? Where are they located? What foramen in the skull does each structure pass through?

Answer 16

• External jugular vein runs superficial to sternocleidomastoid
Deep to sternocleidomastoid is the carotid sheath, which contains:
• Common Carotid A.
• Internal Jugular V.
• Vagus N.
Pass through jugular foramen

Question 17

What blood vessel branches from the common carotid to supply blood to the brain? What foramen does that artery pass through?

Answer 17

Internal carotid artery. Passes through foramen lacerum

Question 18

What are the structures associated with the larynx? What is the function of each structure?

Answer 18

1. Hyoid bone – muscular attachments including tongue and rectus series.
2. Thyroid & Cricoid cartilages - protect the glottis and entrance to the trachea.
3. Epiglottis - leaf-shaped lid, that closes over the glottis when food enters the pharynx
4. Arytenoid cartilage -
   open & close the glottis and assist with sound production

Question 19

What structure(s) are required for phonation? Speaking?

Answer 19

Vocal cords
-thyroid cartilage
-arytenoid
-cricoid
Glottis

Question 20

Describe the location of the carotid sheath and what it contains.

Answer 20

Deep to sternocleidomastoid is the carotid sheath, which contains:
• Common Carotid A.
• Internal Jugular V.
• Vagus N.