Question

Written Assignment:

Using an anatomy atlas, detail the pathways of the six cranial nerves that govern suck-swallow-breathe. I want to know from where they originate, to their pathways through the various foramina and where they end. Are the pathways sensory or motor? If motor, what muscles do they innervate; if sensory, into which nucleus do they terminate?

Instructions:

You may do algorithms diagrams; write out the pathways as if writing an essay; create graphics, etc. I want to know where the nerve starts, what pathway it follows through what foramina, and what it innervates. Is it sensory or motor? Tip: The sucking anatomy video has some of this information in it. An anatomy atlas will be your best friend. You can also use Wilson Pauwells Cranial Nerves book (any edition) as a source.

Answer 1

The six Cranial Nerves (CN) involved in: Suck- Swallow- Breathe, are:

1. Trigeminal Nerve- CN V.
2. Facial Nerve- CN VII.
3. Glossopharyngeal Nerve- CN IX
4. Vagus Nerve- CN X.
5. Spinal accessory Nerve- CN XI.
6. Hypoglossal Nerve- CN XII.

Motor Components	Sensory Components
Trigeminal Nerve- CN V
Efferent portion innervates- a. Muscle involved in chewing, including temporalis, the masseter, the lateral pterygoid. b. Tensor villi palatine muscle (tenses velum) c. Assists Glossopharyngeal Nerve, raising larynx during laryngeal substage of pharyngeal swallow.	Carry all sensory sensations, except taste from anterior two-third of the tongue. Information from face, mandible and mouth.
Facial Nerve- CN VII
Innervates- a. lip muscles, including orbicularis and zygomaticus. B. The muscle contraction during oral preparatory and oral transport stages for swallowing ad preventing food from dribbling out. c. Buccinator muscle of cheek, should remain tensed to prevent pocketing of food, during swallowing.	Carries information of taste from anterior two-third of the tongue.
Glossopharyngeal Nerve- CN IX
Has motor, sensory and autonomic nerve fibres. Innervates- a. Three salivary glands, b. Upper pharyngeal constriction along with Vagus nerve, c. Stylopharyngeus muscles, for larynx elevation.	Carry all sensory sensations, including taste from posterior one-third of the tongue. Information from velum and superior portion of pharynx (lesion impaired gag response unilaterally)
Vagus Nerve- CN X
Innervates: a.The glossopalatine and the levator veli palatine muscles- Responsible for raising the velum. b. Along with CN- the pharyngeal constrictor muscles. c. Along with CN. XI -the intrinsic musculature of the larynx. d. Cricopharyngeus muscle. e. Controls the muscles involved in the oesophageal stage of the swallow as well as those that control respiration	Information from velum and posterior and interior portion of pharynx. Sensation in larynx.
Spinal accessory Nerve- CN XI
Innervates- a. Palatopharyngeal muscle-depresses velum, constricts pharynx. b. Muscular uvula-tenses velum, c. Along with CN X- elevator vela Palatini	Strictly motor nerve
Hypoglossal Nerve- CN XI

Innervates- a. Palatopharyngeal muscle-depresses velum, constricts pharynx. b. Muscular uvula-tenses velum, c. Along with CN X- Levator veli Palatini	Strictly motor nerve
Hypoglossal Nerve- CN XI
Extrinsic and intrinsic tongue muscles. Genioglossus, styloglossus. Strap muscles of glenohyoid.	Strictly motor nerve