Lecture 5: Pharynx and Larynx

Question 1

At what vertebral level does the pharynx end?

Answer 1

C6

Question 2

What are the 3 phases of swallowing?

Answer 2

1. Oral phase: mastification of the food
2. Oropharyngeal phase: elevation of the floor of the mouth and tongue in order to push the bolus into the oropharynx
3. Pharyngeo-esophageal phase: oropharynx elevates and constricts around the bolus, and propels it down the esophagus

Question 3

What are the 3 divisions of the pharynx?

Answer 3

1. Nasopharynx
2. Oropharynx
3. Laryngopharynx

Question 4

The nasopharynx is located posterior to the nasal cavity, how does it communicate w/ the nasal cavity, middle ear cavity, and oropharynx?

Answer 4

Nasal cavity via the choanae

Middle ear cavity via the auditory tube

Oropharynx via the pharyngeal isthmus

Question 5

What part of the pharynx is the palatine tonsil and palatoglossal fold found in?

Answer 5

Oropharynx

Question 6

How does the oropharynx communicate w/ the nasopharynx and oral cavity?

Answer 6

Nasopharynx via the pharyngeal isthmus

Oral cavity via the faucial ishtmus

Question 7

At which levels does the laryngopharynx communicate w/ the oropharynx, via what with the larynx, and the pharynx ends at what vertebral level where it becomes the esophagus?

Answer 7

Oropharynx at the level of the hyoid

Larynx via the laryngeal aditus

Ends at C6 where the pharynx becomes the esophagus

Question 8

What are the piriform recesses and where are they found?

Answer 8

• Posterior and lateral to the arytenoid cartilages in the laryngopharynx
• Food/liquid is deviated laterally by the epiglottis and flows into these recesses

Question 9

Function of the stylopharyngeus muscle, where is it found, and what innervates it?

Answer 9

• Elevates the pharynx during deglutination (major elevator)
• Only muscle innervated by glossopharyngeal (IX) nerve
• Arises from styloid process and inserts on pharyngeal wall between the superior and middle constrictors

Question 10

What are the 3 pharyngal constrictors and their attachments?

Answer 10

1. Superior attached laterally to the pterygomandibular raphe
2. Middle attahced laterally to the hyoid
3. Inferior its horizontal fibers comprise the cricopharyngeus m. (used during pharyngeal speech)

Question 11

Which pharyngeal constrictor muscle has fibers contributing to the cricopharyngeus muscle; what is this muscle used for?

Answer 11

• Inferior constrictor
• Cricopharyngeus m. used during pharyngeal speech

Question 12

Zenker’s diverticulae are frequently located where?

Answer 12

Junction of cricopharyngeus and esophageal musculature; an area devoid of a muscular layer

Question 13

The pharyngeal plexus is found embedded where?

Answer 13

The portion of Buccopharyngeal fascia covering the middle constrictor

Question 14

The retropharyngeal space is found between what layers and is continous between what levels?

Answer 14

• Between the buccopharyngeal fascia and prevertebral fascia
• Continous from the base of the skull to the mediastinum
• Infections can spread from either region via this space

Question 15

The SVE fibers to the pharynx and larynx originate where; exit and travel with what nerves and finally provide motor fibers to what plexus?

Answer 15

• Originate in the nucleus ambiguus
• Exit brainstem w/ the spinal accessory nerve, at level of jugular foramen and join the vagus nerve
• Pharyngeal branches of the vagus supply motor fibers to the pharyngeal plexus, which innervates ALL the pharyngeal muscles EXCEPT stylopharyngeus (glossopharynheal CN IX)

Question 16

The pharyngeal plexus receives GVA and SVE fibers from what nerves; which fibers convey the afferent information for the gag reflex?

Answer 16

• Sensory GVA from the pharyngeal branch of glossopharyngeal n.
• Motor SVE from the pharyngeal branch of the vagus n.
• The GVA fibers in the plexus convey the afferent information for the gag reflex

Question 17

The pharynx is supplied from branches of which arteries?

Answer 17

• Ascending pharyngeal artery
• Inferior thyroid artery

Question 18

Which nerves are tested when examining the gag reflex; which are the afferent and efferent portions?

Answer 18

• Pharyngeal branches of the Glossopharyngeal(CN IX) convey the sensory (afferent) component
• Pharyngeal branches of the Vagus (CN X)mediate themotor (efferent) response

IN BY 9, OUT BY 10

Question 19

What is the GVA and SVA branches of CN IX innervating?

Answer 19

Sensory (GVA) to mucosa of posterior 1/3 tongue and pharynx

Sensory (SVA) to taste buds of posterior 1/3 of tongue

Question 20

What happens inside the pirifom recesses when a patient say “a-a-a” in a low voice; what is the clinical significance?

Answer 20

• Piriform recesses slightly dilate and secretions may gather here, but should dissappear on swallowing
• If secretion do NOT dissapear, the patient has a “pooling” sign, which suggests obstruction or paralysis of the upper esophagus

Question 21

What artery supplies the larynx, including the epithelium in the area of the piriorm recesses?

Answer 21

Superior laryngeal artery

Question 22

What forms the main supporting element of the laryngeal airway and what vertebral level is it at?

Answer 22

• Cricoid cartilage
• Located at level of C6

Question 23

What is the significance of the arytenoid cartilages of the larynx?

Answer 23

• Highly mobile in both rotational and transverse directions
• During phonation, they rotate along a vertical axis to control tension of the vocal folds
• During respiration, they slide laterally to open the rima glottidis

Question 24

What are the valleculae epiglottica; what seprates them; and they are bounded by?

Answer 24

• Cup-shaped recesses between the tongue and epiglottis
• Separeted from one another by the median glossoepiglottic fold
• Bounded laterally by the lateral glossoepiglottic folds

Question 25

What is the signifiance of the valleculae epiglottica during intubation; what happens as the blade moves forward?

Answer 25

- Blade is often placed in the **valleculae epiglottica** - As end of blade is moved forward so is the tongue and epiglottis - This movement opens the **laryngeal aditus** and allows for tube to get into the larynx and below the vocal folds

Question 26

What type of joint is the cricoarytenoid joint?

Answer 26

Combination of **sliding and rotatory** type joint

Question 27

What is the importance of the cricothyroid joint and what nerve sits posterior to it?

Answer 27

- **Circular hinge type** that functions during **increases in pitch** by stretching the **vocal folds** - The **recurrent laryngeal nerve** courses posterior to this joint

Question 28

What does the thyroid membrane extend between and what important neurovasculature pierces this membrane?

Answer 28

- Between the thyroid cartilage and the hyoid bone - Pierced by the: **superior laryngeal artery** and the **internal laryngeal nerve**

Question 29

What is the function of Cricothyroid muscle; what nerve innervates this muscle; what is it opposed by?

Answer 29

- **Increases vocal tension** by tilting the thyroid cartlage forward, causing a hinge, and i**ncreasing pitch** - Only muscle of larynx innervated by **E****xternal Branch of the Superior Laryngeal Nerve of the Vagus** - Opposed by the **Vocalis muscle (decreases tension)**

Question 30

What muscle is the only abductor of the vocal cords; what innervates this muscle?

Answer 30

**- Posterior Cricoarytenoid m.** - Innervated by: **recurrent laryngeal branch of Vagus n.**

Question 31

Which muscles increase and decrease tension of the vocal cords?

Answer 31

**Increase tension** = **Cricothyroid m.** ## Footnote **Decrease tension = Vocalis m.**

Question 32

What is the chief sensory nerve to the interior of the larynx; what type of fibers does it supply?

Answer 32

**- Internal branch of the Superior Laryngeal nerve** from **Vagus** **-** Supplies **GVA sensory fibers** to the interior of the larynx - Supplies parasympathetic **GVE** fibers to the saccule glands of the larynx

Question 33

What represents the afferent component of the **laryngeal expiratory reflex (LER)** and why is this clincally significant?

Answer 33

- Laryngeal receptors and afferent fibers of the **internal branch of the superior laryngeal nerve** - This produces the **protective cough reflex,** if the ibSLN is not functional there is an **increased risk** of developing **aspiration pneumonia**

Question 34

After the recurrent laryngeal nerve cross the cricothyroid joint and enters the larynx what is it called; what type of fibers does it convey; what is its function?

Answer 34

- The **inferior laryngeal nerve** - Conveys **SVE fibers** to the laryngeal muscles, excpet the cricothyroid - These fibers originate from the **Nucleus Ambiguus**

Question 35

Lesions to what nerve result in hoarsness and dysphagia?

Answer 35

Recurrent laryngeal nerve

Question 36

What are the 2 main arteries supplying the larynx, where do they arise from and what main areas do they supply?

Answer 36

1) **Superior thyroid artery** produces **S****uperior Laryngeal Artery**supplying the i**nterior of the larynx** 2) **Inferior thyroid artery** produces the **I****nferior Laryngeal Artery**which supplies the**thyroid gland and parathyroids**

Question 37

Lymph from the larynx primarily drains into which nodes?

Answer 37

Deep cervical nodes

Question 38

What is the laryngeal aditus?

Answer 38

Triangular-shaped opening between the laryngo-pharynx and the larynx

Question 39

What happens to the laryngeal aditus during deglutition (swallowing)?

Answer 39

Collapses inward and is covered by the epiglottis

Question 40

What is the Rima vestibularis?

Answer 40

Elliptical-shaped opening formed by the free edge of the vestibular folds

Question 41

What ligament forms the vocal folds (cords), where do they extend between, and what are their functions?

Answer 41

- Formed by the **vocal ligament** - Extending from the vocal process of the arytenoid cartilages to a point above the inferior notch of the thyroid cartilage - **Primary source of sound during vocalization** **-** Also act as **internal sphincters** of the larynx during **coughing**

Question 42

What is the Rima Glottidis?

Answer 42

Opening formed by the free margin of the vocal cords

Question 43

What is the stimulus for the laryngeal expiration reflex (cough reflex); what supplies the afferent and efferent components?

Answer 43

**Stimulus:** aspiration of material into the laryngeal vestibule **Afferent:** the **internal branch of the superior laryngeal nerve** enter the medulla w/ the vagus nerve and terminate at **nucleus tractus solitarius** **Efferent:** the **recurrent branch of laryngeal, intercostal, and abdominal nerves** all play a role in the abrupt, **involuntary**, **expiratory,** cough \*Remember his story about his dogs anal sphincter closing when he barked. The efferent component of this reflex extends throughout the body!

Question 44

What is the chief rami of the internal branch of the laryngeal nerve invoved in neurological airway protection?

Answer 44

Middle rami

Question 45

Explain laryngeal displacement in the newborn and adult humans?

Answer 45

- Research found that there is a **gradual, progressive descent** of the larynx from newborn to adult position - **Human infants** have functional separation of the airway and swallowing function; epiglottis articulates w/ the soft palate. Infants are able to suckle and nasal breath at the same time. - **Adults** require neurological airway protection, and rapidly adapting receptors (RARs) in larynx

Question 46

Describe the effects of injury to the inferior laryngeal nerve versus the superior laryngeal nerve (both branches)?

Answer 46

**Inferior laryngeal nerve** innervates the laryngeal muscles moving the vocal folds and inury causes paralysis of the vocal folds **Superior laryngeal nerve:** **Internal branch** innervates the superior laryngeal mucosa and injury results in loss of protective mechanism to keep foreign bodies out of larynx: **External branch** innervates the cricothyroid muscle and injury leads to a voice that is monotonous in character due to cricothyroid not being able to vary length and tension of the vocal fold

Question 47

What nerve is most in danger for being taken out when removing the palatine tonsils surgically?

Answer 47

Glossopharyngeal N. (CN IX)