2.1 Neurology of Swallowing

Question 1

What cranial nerves do we have to know?

5

Answer 1

• Trigeminal (V)
• Facial
• Glossopharyngeal
• Vagus (X)
• Hypoglossal

.

Question 2

Are motor/efferent nerves ascending or descending?

Answer 2

Descending

Question 3

Are sensory/afferent nerves ascending or descending?

Answer 3

Ascending

Question 4

What is important to know about the ophthalmic branch of the trigeminal nerve?

(2)

Answer 4

Sensory

Not involved in swallowing

Question 5

What is important to know about the maxillary branch of the trigeminal nerve?

(2)

Answer 5

Sensory

Upper lip, maxillary teeth and palate

.

Question 6

What is important to know about the mandibular branch of the trigeminal nerve?

(4+4)

Answer 6

Sensory: Anterior 2/3rd of tongue, mucous membranes of mouth/cheek, gums, TMJ

Motor: Masticatory muscles, Tensor veli palatini, mylohyoid and anterior belly of digastric.

.

Question 7

What are the mastication muscles?

4

Answer 7

Masseter

Temporalis

Lateral pterygoid

Medial pterygoid

.

Question 8

What does the trigeminal nerve guide and control?

Answer 8

The mastication process

Question 9

What part of the tongue is the trigeminal nerve responsible for?

Answer 9

responsible for the sensation of the general anterior 2/3rds of the tongue

Question 10

What branch is responsible for the sensation of the facial nerve?

Answer 10

Chorda Tympani branch (taste anterior 2/3rd of the tongue)

Question 11

What motor movements is the facial nerve responsible for?

2

Answer 11

Temporal, Zygomatic: Not involved in swallowing

Lip sphincter: Buccal, Mandibular and cervical

.

Question 12

In regards to SENSATION, what are the two visceral afferents of the glossopharyngeal nerve?

(2)

Answer 12

Taste sensation from the posterior third of the tongue

The mucous membranes of part of the tongue, tonsil, and upper pharynx

.

Question 13

In regards to the MOTOR movements, what is the special visceral efferent of the glossopharyngeal nerve?

Answer 13

Stylopharyngeus

.

Question 14

What constrictors are controlled by the glossopharyngeal nerve?

Answer 14

pharyngeal constrictors

Question 15

In regards of the vagus nerve, what does the internal branch of the SLN provide sensation for?

(3)

Answer 15

Vallecular mucosa

General hypopharynx

Larynx

.

Question 16

What does the vagus nerve provide motor movements for?

4

Answer 16

velum

Pharynx

Larynx

Esophagus

.

Question 17

What tongue muscles does the hypoglossal nerve provide motor movements for?

Answer 17

all tongue muscles except the palatoglossus

Question 18

In regards to brainstem control, sensory information from the pharynx is relayed by afferent fibers which terminate where?

Answer 18

In the nucleus of the tractus solitarius (NTS) in the medulla

Question 19

In regards to brainstem control, sensory information can also be sent by afferent fibers to where?

Also, where does this begin?

Answer 19

different regions of the cerebrum

This begins the cortical response to swallowing

Question 20

What is the nucleus ambiguous (NA) in the medulla?

2

Answer 20

the principle motor nucleus

Provides input to the cranial nerves

Question 21

What brodmann area is the primary motor cortex?

Answer 21

Area 4

Question 22

What brodmann area is the premotor cortex?

Answer 22

Area 6

Question 24

What is the first step of the Volitionary Pathway (1)?

Answer 24

Sensory information reaches the somato-sensory cortex via the thalamus

Question 25

What is the second step of the Volitionary Pathway (1)?

2

Answer 25

Sensory information from the Somatosensory areas are relayed to the motor cortex

Then motor commands are initiated.

Question 26

What is the third step of the Volitionary Pathway (1)?

Answer 26

Motor commands reach the periphery through cortico-bulbar pathways.

Question 27

What is the first step of the Reflexive Pathway (2)?

Answer 27

Sensory information reaches the nucleus tractus solitarius (NTS)

Question 28

What is the second step of the Reflexive Pathway (2)?

Answer 28

Sensory information from the nucleus tractus solitarius (NTS) is relayed to the reticular formation system and in turn to nucleus ambiguous (NA)

.

Question 28

What brain activation are involved in swallowing?

10

Answer 28

Inferior precentral gyrus – bilaterally

Primary somatosensory area (BA 43)

Right Premotor cortex

Right Precentral Gyrus

Right Anterior Insula

Left cerebellum

Basal ganglia

Thalamus

Right temporal gyri

Right inferior parietal lobe

.

Question 29

What is the third step of the Reflexive Pathway (2)?

Answer 29

Motor commands modulated by nucleus ambiguous (NA) reach the periphery.

Question 30

Where is the insula lobe located?

Answer 30

Located beneath the juncture of frontal, temporal, and parietal lobes

Question 31

What does the insula lobe coordinate?

1+3

Answer 31

Interaction of …

Oral musculature

Gustation (taste)

Alimentary tract (digestion)

.

Question 32

What does the insula connect to?

4

Answer 32

Primary motor cortex

Supplementary motor cortex

Thalamus

Nucleus tractus solitarii (NTS)

.

Question 33

What does lesions of the right anterior insula do?

2

Answer 33

Reduced sensory input causes delayed swallow

Decreased sensory input – taste, volume, temperature

Question 34

What does the cerebellum connect?

4

Answer 34

Primary motor cortex

Supplemental motor cortex

Brainstem

Thalamus

.

Question 35

What is the cerebellum an intensifier of?

Answer 35

Intensifier of responses

Question 36

What is the purpose of the cerebellum?

3

Answer 36

Timing

Coordination

Sequencing

Question 37

What does the cerebellum integrate? (3)

What does this do?

Answer 37

Proprioceptive info

Vestibular info

Motor planning

Create smooth movements.