study guide 5-6

Question 1

Question 2

What is a nerve plexus?

Answer 2

Network of converging and diverging branches of nerves

Question 3

Give a general description of how the pharyngeal plexus is formed

Answer 3

3 cranial nerves contribute to the plexus – the glossopharyngeal (cranial nerve IX) vagus (cranial nerve X) and accessory (cranial nerve XI). Motor nerves found in the plexus are contributed by the vagus and accessory nerves, while sensory fibres in the plexus ultimately join the glossopharyngeal nerve.

Question 4

What is an aponeurosis?

Answer 4

A flat tendon of one muscle that acts as an attachment point for other muscles

Question 5

Which muscle forms the palatine aponeurosis, and which muscles attach to the palatine aponeurosis?

Answer 5

The palatine aponeurosis is formed by the tensor veli palatini muscle. Other muscles attaching to it are the levator veli palatini, palatopharyngeus, and palatoglossus.

Question 6

Describe the detailed innervation of the tongue

Answer 6

Motor innervation – the whole tongue (all intrinsic and extrinsic tongue muscles) is supplied with motor fibres by the hypoglossal nerve (cranial nerve XII; unless you count the palatoglossus, which is not innervated by the hypoglossal nerve, but rather by the accessory nerve [XI], or according to some sources, the pharyngeal plexus).

General sensory –The anterior two thirds of the tongue transmits general sensory info via the trigeminal nerve (cranial nerve V). The posterior one third of the tongue transmits general sensory information via the glossopharyngeal nerve (cranial nerve IX).

Special sensory (taste) – The anterior two thirds of the tongue transmits taste info via the facial nerve (cranial nerve VII). The posterior one third of the tongue transmits taste information via the glossopharyngeal nerve (IX).

Question 7

Which artery supplies the tongue

Answer 7

Lingual artery

Question 8

Name and describe the attachments of the extrinsic tongue muscles - ie, including the palatoglossus

Answer 8

Hyoglossus – hyoid bone and tongue

Styloglossus – styloid process and tongue

Genioglossus – inner surface of mandible and tongue

Palatoglossus – soft palate/palatine aponeurosis and tongue

Question 9

Describe the major movements the soft palate is capable of, with reference to the muscles of the soft palate

Answer 9

Tension – the soft plate can become firm and tense, this mainly occurs during speech and occurs by the actions of the tensor veli palatini.

Elevation – the soft palate is elevated during swallowing to close off the nasal cavity and prevent food/liquid from entering the nasal cavity. The soft palate is also elevated during most speech sounds. Elevation is achieved by the actions of the uvular muscle and levator veli palatini.

Depression – the soft palate is depressed during only a couple of speech sounds. It is also depressed when breathing through the nose when the mouth is open (try this one at home – you might feel your uvula being depressed – this prevents air escape through your open mouth). Depression is achieved through the actions of palatoglossus and palatopharyngeus (note the dual actions of these two muscles- palatoglossus is ALSO a tongue elevator, and palatopharyngeus is also a pharyngeal elevator).

Question 10

Can you roll up the sides of your tongue? If so which muscles are responsible?

Answer 10

This is mostly through the actions of the transverse muscle, but can be assisted by the superior longitudinal. The ability to do this action is controlled genetically, if you can’t, it doesn’t mean that you don’t have a transverse muscle, just that the one you have is unable to make this specific movement.

Question 11

Describe the muscles that make up the floor of the mouth.

Answer 11

This is mostly made up of the suprahyoid muscles layering on top of one another. Directly inferior to the genioglossus is the geniohyoid muscle.

Inferior to that is the mylohyoid muscle, and inferior to that is the digastric muscle. All these muscles run between the hyoid bone and the inner border of the mandible.

Question 12

What is the function of the rugae on the hard palate?

Answer 12

These are the ridges in the anterior hard palate – they provide traction for tongue fixation during speech, chewing and swallowing.

Question 13

What are the differences between glottal attack, breathy attack, and simultaneous attack?

Answer 13

Glottal attack – vocal fold adduction occurs before the onset of exhalation/air flow

Breathy attack – exhalation begins before vocal fold adduction

Simultaneous attack – airflow and adduction occur together

Question 14

What are the three main factors that produce sub-glottal pressure?

Answer 14

• Alterations in the respiratory cycle (longer exhalation time)
• Use of respiratory muscles to control small bursts of air
• Use of functional residual volume to increase lung pressure without first inhaling – residual volume is the air remaining within the lungs after we have exhaled in a normal respiratory cycle (note, your text uses the term “functional residual capacity” – same thing).

Question 15

In which phase/stage of phonation would the following muscles be involved?

Answer 15

1. Posterior cricoarytenoid (stage 3 – vocal fold abduction)
2. Cricothyroid (stage 2 – vocal folds held in fixed position, but may change in tension/length for pitch alteration)
3. Transverse arytenoid (stage 1 – vocal fold adduction)
4. Thyromuscularis (stage 2 - vocal folds held in fixed position, but may change in tension/length for pitch alteration)

Question 16

What are the two muscles that are used to lengthen the vocal folds to increase pitch?
Which of these is the primary lengthening muscle, and which one fine tunes?

Answer 16

Cricothyroid – this is the primary lengthening muscle and therefore the primary pitch controller.

Thyrovocalis – actually causes change in tension and is the fine tuner to increase pitch.

Question 17

Revise the anatomy of the articulators. For each of the following provide a description using accurate anatomical terminology. Note: your answers here will also vary. You don’t have to have come up with the exact answer as me, as long as you’re on the right track.

Answer 17

1. Oral cavity – bounded by the cheeks laterally, lips and mandible anteriorly, hard palate superiorly, and oropharynx posteriorly. The floor of the mouth is comprised primarily of the suprahyoid muscles (geniohyoid, mylohyoid and digastric muscles).
2. Buccal cavity – this is the cavity found between the inside of the cheeks and the anterior surface of the teeth. The vestibule of the oral cavity consists of the entire area between the lips, cheeks and teeth.
3. Nasal cavity – bounded inferiorly by the hard palate, and formed by the nasal bones, inferior nasal conchae, and vomer. The lateral and anterior boundaries are formed by the soft tissue of the nose. The posterior boundary is the nasal choanae that open into the nasopharynx.
4. Pharyngeal cavity – This runs from the supero-anterior boundary of the nasal choanae, to the laryngeal aditus (superior opening of the larynx) and superior opening of the oesophagus. The most superior part is the nasopharynx, middle part is the oropharynx (posterior to nasal cavity) and the most inferior part is the laryngopharynx.

Question 18

List the mobile and immobile articulators

Answer 18

Mobile (moveable): tongue, lips, pharynx, mandible, soft palate, cheeks, larynx, hyoid bone

Immobile: teeth, hard palate

Question 19

What is the function of the paranasal sinuses in speech?

Answer 19

Contribute to vocal resonance (this is why your voice sounds flat and dull when your sinuses are blocked, such as when you have a cold, hayfever, or sinusitis).

Question 20

Damage to the hypoglossal nerve would affect which phase of deglutition?

Answer 20

The main job of the hypoglossal nerve is to supply the intrinsic and extrinsic tongue muscles with motor fibres – so damage to this nerve will essentially paralyse the tongue, and primarily affect the oral preparatory and oral phases of deglutition.

Question 21

What is the role of the pharyngeal constrictors in swallowing

Answer 21

They contract sequentially from superior constrictor, middle constrictor, to inferior constrictor, to force the bolus of food into the oesophagus.

Question 22

What will happen if the nasopharynx is not closed off properly during swallowing?

Answer 22

Nasal regurgitation will occur.

Ever had milk or Coke come out your nose when someone has made you laugh while trying to swallow?

More seriously however, this can be a difficult issue for people with partial or complete paralysis of the palatine elevators, causing regular nasal aspiration/regurgitation of fluids.

Question 23

1. Which muscle(s) elevates and retracts the tongue?

Answer 23

Styloglossus

Question 24

1. Which cranial nerve innervates the palatoglossus muscle?

Answer 24

Pharyngeal plexus from the XI accessory (mainly) and X vagus nerves

Question 25

1. Where would you find the genioglossus muscle?

Answer 25

• The genioglossus is the “prime mover” of the tongue, and makes up most of its deeper bulk. It arises from the inner mandibular surface and inserts into the top and dorsum of the tongue as well as to the corpus of the hyoid bone. Innervated by the XII Hypoglossal nerve.*
• Anterior fibres RETRACT the tongue. Posterior fibres PROTRUDE the tongue. Together they depress the tongue.*

Question 26

1. What are the two groups (or types) of tongue muscles?

Answer 26

• Extrinsic and intrinsic tongue muscles. Extrinsic tongue muscles are: genioglossus, styloglossus, palatoglossus, hyoglossus, (plus chrondroglossus, often considered to be part of the hyoglossus). (Mnemonic: Genius, HY style, palate)*
• Intrinsic tongue muscles are: superior and inferior longitudinal, transverse and vertical.*
• Generally the extrinsic tongue*

Question 27

1. What is its innervation?

Answer 27

Glossopharyngeal nerve (IX) (If you’ve got GLOSS you’ve got SYLE.)

Question 28

1. One of the tongue muscles is attached to the hyoid bone. True or False?

Answer 28

True: the hyoglossus.

Question 29

1. Is the central sulcus of the tongue the same as the lingual septum?

Answer 29

No. The central sulcus divides the tongue into right and left. The sulcus is just a shallow division or visible dividing line. The lingual septum lies deep to the central sulcus. It is a fibrous septum important for muscle attachment.

Question 30

1. Are the extrinsic tongue muscles paired or unpaired?

Answer 30

They are paired: ie, occur on each side of the body

Question 31

1. What are the attachments of the hyoglossus muscle?

Answer 31

Hyoid bone to the side of the tongue

Question 32

1. Which cranial nerve transmits special sensory information (taste)

from the anterior 2/3 of the tongue?

Answer 32

The facial nerve (VII).

Question 33

What is the function of the styloglossus muscle

Answer 33

Elevate and retract the tongue

Question 34

1. Which muscle flattens and broadens the tongue?

Answer 34

The vertical (intrinsic) muscle

Question 35

1. Where is the mylohyoid muscle located, in relation to the geniohyoid muscle?

Answer 35

Lies inferior to the geniohyoid.

Question 36

There are 4 muscles contained within the body of the tongue (intrinsic):

Answer 36

1)Superior longitudinal

2)Verticalis

3)Transversus

4) Inferior longitudinal

Question 37

There are 4 muscles that connect the tongue with the skeleton (extrinsic):

Answer 37

1)Genioglossus

2)Hyoglossus

3)Styloglossus

4)Palatoglossus

Question 38

muscles involved in chewing

Answer 38

Temporalis, Masseter, Internal (Medial) Pterygoid,

External (Lateral) Pterygoid, Supra- and Infrahyoid muscles, Temporomandibular joint (TMJ)