Control L3 the head and neck Flashcards
(223 cards)
1
Q
What are the four main muscles of mastication?
A
- Masseter
- Temporalis
- Lateral pterygoid
- Medial pterygoid
2
Q
What is the main accessory muscle of mastication?
A
Double bellied digastric muscle
3
Q
What is in the joint capsule at the temporomandibular joint?
A
Articular disc and two spaces filled with synovial fluid
4
Q
What is the origin of the masseter muscle?
A
the zygomatic arch
5
Q
Where does the masseter muscle insert?
A
onto the ramus of the mandible by the mandibular angle
6
Q
What happens when the masseter muscle contracts?
A
the mandible is elevated towards the maxilla.
7
Q
What movements of the jaw is the masseter involved in?
A
Elevation and protrusion
8
Q
What travels through the space created by the mandibular notch?
A
a neurovascular bundle
9
Q
What artery supplies the masseter?
A
The masseteric artery
10
Q
What nerve innervates the masseter?
A
masseteric nerve (from the trigeminal nerve)
11
Q
Where does Temporalis muscle originate?
A
Temporal fossa
12
Q
Where does the Temporalis muscle insert?
A
coronoid process of the mandible
13
Q
How does the Temporalis muscle move the mandible/jaw?
A
Elevates and retracts
14
Q
What innervates the Temporalis muscle?
A
deep temporal nerve (branch of the trigeminal nerve)
15
Q
What artery supplies Temporalis?
A
deep temporal artery
16
Q
Where does the lateral pterygoid muscle originate?
A
the lateral surface of the lateral pterygoid plate and the greater wing of the sphenoid bone.
17
Q
Where does the lateral pterygoid muscle insert?
A
neck of the condylar process of the mandible and the articular disc of the temporomandibular joint capsule
18
Q
How does the lateral pterygoid move the jaw/mandible?
A
Depresses and moves it medially causing side to side movements
19
Q
What innervates the lateral pterygoid muscle?
A
The nerve to the lateral pterygoid from the mandibular division of the trigeminal nerve
20
Q
What artery supplies the lateral pterygoid muscle?
A
the pterygoid branches of the maxillary artery and the ascending palatine branches of the facial artery
21
Q
How many heads do both the lateral and medial pterygoid muscles have?
A
Two each (upper and lower for lateral and anterior and posterior for medial)
22
Q
Where does the medial pterygoid muscle originate from?
A
the posterior surface of the maxilla and medial surface of the lateral pterygoid plate of the sphenoid bone
23
Q
Where does the medial pterygoid muscle insert?
A
Medial/deep surface if the ramus of the mandible (near the mandibular angle)
24
Q
How does the medial pterygoid muscle move the jaw/mandible?
A
Elevate, protrude and move the jaw side to side (like a cow chewing)
25
What nerve innervates the medial pterygoid muscle?
Nerve to the medial pterygoid from the mandibular branch of the trigeminal nerve
26
What artery supplies the medial pterygoid muscle?
The pterygoid branches of the maxillary artery and the muscular branches of the facial artery
27
Where does the medial pterygoid muscle lie in comparison to the lateral pterygoid muscle?
Deep to the lateral pterygoid
28
How does the digastric muscle act as an accessory muscle of mastication?
It helps depress the jaw/mandible.
29
How many bellies does the digastric muscle have?
Two - anterior and posterior bellies
30
Which muscle travels through a small loop of collective tissue attached to the hyoid bone?
The digastric muscle
31
What separates the posterior and anterior bellies of the digastric muscle?
One muscle belly forms a tendon which passes through the connective tissue loop on the hyoid bone and then becomes muscular again and forms the other muscle belly.
32
Where does the digastric muscle originate?
the mastoid process
33
Where does the digastric muscle insert?
onto the digastric fossa of the mandible
34
What movement is caused by the digastric muscle?
Depression of the mandible or elevation of hyoid bone
35
What nerve innervates the anterior belly of the digastric muscle?
The mylohyoid nerve which originates from the trigeminal nerve
36
What nerve innervates the posterior belly of the digastric muscle?
The facial nerve
37
What artery supplies the anterior belly of the digastric muscle?
The submental branch of the facial artery
38
What artery supplies the posterior belly of the digastric muscle?
the posterior auricular and occipital arties
39
What happens in the temporomandibular joint capsule when the jaw is depressed?
The condylar process moves out of the mandibular fossa.
40
What are the two synovial cavities in the temporomandibular joint capsule?
superior and inferior - separated by articular disc
41
What is the tubercle anterior to the mandibular fossa called?
Articular tubercle
42
What must happen to allow the rotation of the condylar process?
Forward displacement of the condylar process from the mandibular fossa
43
What allows for the sliding of the condylar head during depression of the mandible?
The action of the lateral pterygoid muscle stretching the articular disc in the joint capsule forward towards the articular tubercle. Once the articular disc reaches the articular tubercle, the condylar head becomes displaced from the mandibular fossa.
44
What happens at the temporomandibular joint capsule during elevation of the mandible?
The condylar head retracts back into the mandibular fossa bringing the articular disc with it
45
What can cause a clicking/popping sound and pain when elevating the jaw?
The articular disc not moving back into the joint capsule alongside the condylar head.
46
What disease is caused by chronic failure of the articular disc to move back into place with the condylar head upon mandibular elevation?
TMJ dysfunction
47
What prevents excessive sideways and backwards movement of the mandible when elevated?
The stability of the joint capsule due to the shape of the temporal bone and the ligaments preventing hyper retraction.
48
In what position/state is the mandible most likely to be dislocated from the temporomandibular joint?
When the mandible is depressed or when you open your mouth too wide overstretching the muscles and causing the condylar process to get pulled, and stuck, in front of the articular tubercle.
49
What cranial nerve is the trigeminal nerve?
Nerve V
50
What are the three branches of the trigeminal nerve? What is the shorthand for each?
V1 = opthalmic nerve
V2 = maxillary nerve
V3 = mandibular nerve
51
What ligaments cause wrinkles as we age and the skin around them sags?
Retaining ligaments
52
What are the main soft tissue layers of the face? (From most superficial to deepest)
1. Skin
2. Subcutaneous fat
3. Superficial muscular aponeurosis layer/ system (SMAS) containing muscles and retaining ligaments
53
What is the main role of the SMAS?
To produce facial expressions
54
What muscle is located on the cheek?
The buccinator muscle
55
What is the anatomical name for the corner of the mouth?
Oral commissure
56
Where do lots of the facial muscles articulate/blend together?
Next to the oral commissures
57
What is the area by the oral commissures where lots of facial muscles meet known as?
Modioli
58
Where does the orbicularis orus muscle originate?
Medial aspect of mandible and maxilla, the perioral skin (i.e. skin around the mouth) and modiolus
59
Where does the orbicularis orus muscle insert?
The skin and mucous membrane of the lips
60
What movement is produced by the orbicularis orus?
Closing the mouth, compresses and protrudes the lips.
61
Where does the depressor anguli oris muscle originate?
The mental tubercle and the oblique line of the mandible
62
What other muscle is the depressor anguli oris continuous with at its origin?
The platysma muscle
63
Where does the depressor anguli oris muscle insert?
The modiolus
64
What movement is caused by the depressor anguli oris?
Decompression of the angles of the mouth i.e. frowning
65
Where does the Levator anguli oris muscle originate?
The canine fossa of the maxilla
66
Where does the levator anguli oris muscle insert?
Modiolus
67
What movement is caused by the Levator anguli oris?
Elevation of the angle of the mouth i.e. smiling
68
Where does the zygomaticus major muscle originate?
The posterior part of the lateral aspect of the zygomatic bone
69
Where does the zygomaticus major muscle insert?
Modiolus - blending with muscles of the upper lip
70
What movement is caused by the zygomaticus major muscle?
Elevating and everting (widen the smile bringing check muscles backwards) the angle of the mouth
71
Where does the depressor labii inferioris muscle originate?
The oblique line of the mandible
72
What muscle is the depressor labii inferioris continuous with?
Platysma muscle
73
Where does the depressor labii inferioris muscle insert?
Skin and submucosa of the LOWER lip
74
What movement is caused by the depressor labii inferioris?
Depression of lower lip inferolaterally
75
Where does the levator labii superioris muscle originate?
The zygomatic process of the maxilla and the maxillary process of the zygomatic bone
76
Where does the levator labii superioris muscle insert?
Blends with muscles of upper lip
77
What movement is caused by the levator labii superioris muscle?
Elevation of upper lip exposing the maxillary teeth
78
Where does the zygomaticus minor muscle originate?
Anterior part of the lateral aspect of the zygomatic bone
79
Where does the zygomaticus minor muscle insert?
It blends with the muscles in the upper lip blending medially to the zygomaticus major muscle.
80
What movement is caused by zygomaticus minor?
Elevates the upper lip exposing the maxillary teeth.
81
Where does the mentalis muscle originate?
The incisive fossa of the mandible
82
Where does the mentalis muscle insert?
The skin of the chin
83
What movement is caused by the mentalis muscle?
Elevating, everting and protruding the lower lip, wrinkling the skin of the chin
84
What is the nickname for the menatlis muscle?
The sulking muscle
85
What muscles are known as the dilators of the mouth?
Depressor anguli oris
Levator anguli oris
Zygomaticus major
Zygomaticus minor
Depressor labii inferioris
Levator labii superioris
Mentalis muscle
86
Where does the buccinator muscle originate?
- Superiorly at the alveolar process of the maxilla
- inferiorly at the alveolar part of the mandible
- posteriorly at the pterygomadibular raphe and buccinator crest of the mandible
87
Where does the buccinator muscle insert?
Modiolus blending with other muscles of upper lip
88
What movement is caused by the buccinator muscle?
Compression of the cheeks against the molar teeth i.e. sucking/suckling
89
What major role in maceration does the buccinator have?
Controls the bolus of food in the mouth
90
What nerve supplies all the facial muscles?
The facial nerve
91
What are the 6 branches of the facial nerve that are involved in innervating the facial muscles?
1. Temporal
2. Posterior auricular
3. Zygomatic
4. Buccal
5. Cervical
6. Marginal manibular
92
What cranial nerve is the facial nerve?
Cranial nerve VII
93
How do the 6 nerve branches of facial muscle innervation get from the brain to the muscles?
1. From the brain, they travel through a canal in the petrous temporal bone
2. They emerge from the skull and pass through the parotid gland (the largest of the salivary glands) to reach the muscle they are innervating
94
Where do the parotid glands sit?
On the side of the face anterior to the ear
95
Where does the temporal branch of the facial nerve travel to?
Emerges from the parotid gland and travels up the face behind the eyebrow and forehead
96
Where does the zygomatic branch of the facial nerve travel to?
Emerges from the parotid gland and travels down the cheekbones and under the eye towards the nose
97
Where does the buccal branch of the facial nerve travel to?
Emerges from the parotid gland and travels down the cheeks towards the modioli
98
Where does the marginal mandibular branch of the facial nerve travel to?
Emerges from the parotid gland and travels along the mandible/jaw
99
Where does the cervical branch of the facial nerve travel to?
Emerges from the parotid gland and travels below the mandible/jawline
100
What nerve supplies almost all the oral cavity with sensory innervation and is the main sensory nerve of the face (the skin and most of the facial cavities)?
The trigeminal nerve
101
What is the large swelling of the trigeminal nerve just after it leaves the brain called?
The trigeminal ganglion
102
What is the trigeminal ganglion formed of?
All the cell bodies of trigeminal sensory nerves.
103
What are the three large sensory nerves originating from the trigeminal nerve?
V1, V2 and V3
104
Where does the V1 nerve travel?
From the trigeminal ganglion behind the eye and out through the orbital cavity and over the nose and forehead.
105
Where does the V2 nerve travel?
From the trigeminal ganglion past the maxilla and behind the zygomatic bones . One branch travels behind the eye and the other travels over the upper lip and the bottom of the nose (not the tip)
106
Where does the V3 nerve travel?
From the trigeminal ganglion and branches upwards over the side of the head and downwards over the mandible.
107
What is the function of the hyloid bone?
lifts and supports the larynx during swallowing to prevent the inhalation of food into the respiratory tract
108
What three vessels branch from the arch of the aorta?
brachiocephalic artery
Left subclavian artery
Left common carotid artery
109
What branches from the brachiocephalic artery?
The right common carotid artery and the right subclavian artery
110
Where do the common carotid arteries bifurcates?
At the level of the laryngeal prominence aka the Adam’s apple
111
What arteries does the common carotid artery bifurcate into? What area(s) of the body do they supply?
The external carotid artery = the face
The internal carotid artery = the brain
112
The external carotid artery is deep to the internal carotid artery. True or false?
False - the internal carotid artery is deeper
113
Where does the internal carotid artery terminate?
At the middle cerebral artery
114
Which branch of the internal carotid artery supplies the face with blood? Which part of the face?
Ophthalmic artery - forehead and eyelids
115
Which arteries supplying the face does the external carotid artery give rise to?
Lingual artery
Facial artery
Maxillary artery
Middle meningeal artery
116
Which nerve does the lingual artery run with?
The hypoglossal nerve
117
Which bone does the facial artery run beneath?
The mandible
118
What branches are given off of the facial artery?
Inferior labial artery
Superior labial artery
Angular artery
119
What does lingual artery supply?
tongue, sublingual gland, gingivit (gums) and oral muscosa of floor of the mouth
120
Where does the inferior labial artery run?
Deep to the bottom lip
121
Where does the superior labial artery run?
deep to the top lip
122
Where does the angular artery run?
The side of the nose
123
What does the maxillary artery supply?
The muscles of mastication and the teeth
124
What are the main arterial anastomoses in the face?
Maxillary artery with meningeal artery - anastomose pre-auricularly
Facial artery and ophthalmic artery (on side of nose as they leave the orbit)
125
What are the veins that drain the teeth? Which teeth?
Posterior superior alveolar vein - molars
Anterior superior alveolar vein - incisors
Inferior alveolar vein -mandibular teeth
126
What vein do the anterior and posterior superior alveolar veins drain into? What plexus is here?
Maxillary vein
Pterygoid venous plexus
127
Which sinus does the pterygoid venous plexus communicate with?
The cavernous sinus
128
What is a common cause of damage to the pterygoid venous plexus?
A superior alveolar nerve block during dental work
129
Which vein does the maxillary vein drain into?
Retromandibular vein
130
Which two veins combine to form the common facial vein?
The facial vein and a branch of the retromandibular vein
131
What vein does the common facial vein drain into?
IJV
132
The branch of the retromandibular vein not forming the common facial nerve, drains into what vessel?
The EJV
133
Where in the body is there no lymphatic drainage?
Brain
134
What is the function of the lymphatic system?
Drain tissue fluid from the tissues back into the venous system
Involved in immune surveillance and response
135
What are lymph nodes?
Sacks of immune cells which detect foreign antigens in the tissue fluid and trigger an immune response (usually)
136
Where are some clusters of lymph noses in the face and neck?
Under the chin and mandible, in front of the ear, near the mastoid process and at the back of the neck where it joins the head, below the ear running with the EJV
137
What is the role of the larynx?
Allows phonation i.e. produce sound
Protection of the airways e.g. coughing and moves during swallowing
138
Which muscle sits superiorly to the oesophagus?
Inferior constrictor muscle of the pharynx
139
Where is the larynx positioned?
Anteriorly to the inferior constrictor muscle, superior to the trachea and anteriosuperior to the oesophagus
140
What park of extrinsic laryngeal muscles attach to the hyoid bone?
141
What is the largest cartilage in the larynx?
The thyroid cartilage where the thyroid gland sits
142
Where does the thyroid hyoid membrane attach?
Superior horns of the thyroid cartilage (left and right)
143
Which part of the thyroid cartilage does the cricoid cartilage articulate with?
The inferior horns (left and right)
144
What allows the epiglottis to act as a hinge?
The epiglottic cartilage
145
Where does the epiglottic cartilage attach to?
The deep surface of the anterior thyroid cartilage and inferioanteriorly to the hyoid bone
146
How does the epiglottic cartilage attach to the thyroid cartilage?
Via the thyroepiglottic ligament
147
How does the epiglottic cartilage attach to the hyoid bone?
The hyoepiglottic ligament
148
Which complete circular ring of cartilage sits between the thyroid cartilage and the trachea?
The cricoid cartilage
149
How does the cricoid cartilage articulate with the thyroid cartilage?
Via the cricothyroid membrane
150
What cartilage allows the vocal folds to open?
The arytenoid cartilage
151
Which movements do the arytenoid cartilage have the ability to make?
Abduction (open the vocal folds) and Adduction (close the vocal folds)
152
Where do muscles attach to the arytenoid cartilages?
At the muscular process
153
What sits in the anterior aspect of the arytenoid cartilages?
The vocal process
154
What is the role of the vocal process of the arytenoid cartilage?
Anchoring the vocal folds
155
What cartilage sits on the superior aspect of the arytenoid cartilages?
The corniculate cartilages
156
What connects the thyroid cartilage to the hyoid bone?
The thyrohyoid membrane
157
What structure is a result of a thickening in the middle of the thyrohyoid membrane?
The median thyrohyoid ligament
158
How many holes (thyrohyoid apertures) are in the thyrohyoid membrane? What is there function?
2
Allow for transport of the neurovascular bundles into the intrinsic muscles of the larynx
159
What can be pierced to allow for emergency airway access?
The cricothyroid membrane
160
What connects the vocal processes to the vocal folds?
The vocal ligaments
161
What structure allows us to phonate?
The vocal ligaments
162
What is the only known sound not to be made by the vocal ligaments?
Burping
163
What joint occurs at the articulation of the cricoid and thyroid cartilages? What is its role?
The cricothyroid joint
To allow movement anteriorly and posteriorly to change the tension of the vocal folds subtly changing the tone of voice
164
What is the role of the cricoarytenoid joint?
Allows abduction and adduction of the vocal folds to produce sounds
165
Which muscles crosses the cricoarytenoid joints? What do they do?
The adductors of the vocal folds = oblique arytenoid muscle and the transverse arytenoid muscle
Assist in adduction of the vocal folds
166
Where do the adductors of the vocal folds insert? What are they innervated by?
Muscular process of the arytenoid cartilages
Recurrent laryngeal nerve and the left and right vagus nerve (cranial nerve X)
167
What is the main abductor muscle in the larynx?
The posterior cricoarytenoid muscles
168
What is the name for the space between the laryngeal folds that is a continuation of the laryngeal inlet and trachea?
The glottis
169
Damage to which nerve or muscles can cause respiratory distress and permanent hoarseness of voice?
The recurrent laryngeal nerve or the abductor and/or adductor muscles of the larynx causing the same side vocal folds to fail to open
170
Why is a tumour in the mediastinum a risk to the larynx?
As it may effect the right recurrent laryngeal nerve
171
How does the crycothyroid muscle affect voice?
It draws the cartilage inferiorly opening out the vocal folds for higher pitch sound
172
How does the thyroarytenoid muscle affect voice?
Applies tension to the vocal folds reducing vibrations and lowering pitch
173
What is the only muscle in the larynx to be innervated by the external laryngeal nerve rather than the recurrent laryngeal nerve?
The cricothyroid muscle
174
Where does the external laryngeal nerve arise from?
From the superior laryngeal nerve of the vagus nerve from the inferior vagal ganglion in the neck
175
Sensory Innervation of the larynx is provided by the same nerves as the motor Innervation. True of false?
True
176
What is the tension of the vocal ligaments like during phonation? Why?
The tension is high to allow inflection in tone
177
How do the vocal ligaments change when whispering?
Tension is further increase almost occluding the vocal folds
178
What causes a change in tone when whispering?
The shape of the mouth as the glottis is almost completely occluded so the vocal folds cannot move to affect tone
179
How do the thyrohyoid muscles move during swallowing?
They pull the larynx superiorly towards the hyoid bone
180
How do the aryepiglottic and thyroepiglottic muscles move during swallowing?
They pull the epiglottis inferiorly to close off the airway
181
What reflexes do the larynx act on to protect the airway?
Laryngeal adductor/glottis closure reflex = vocal folds snap shut in response to stimuli e.g. drowning
Laryngeal expiration reflex/laryngeal cough = forced expiration against a closed glottis to eject debris
Pharyngoglottal closure/gag reflex = prevents aspiration of premature entry of liquids in the oropharynx .
182
What is the role of saliva?
Lubricate food for swallowing
starts chemical digestion
acts as an antimicrobial for the mouth
rebalances mouth Ph of oral cavity (preventing tooth decay)
Assists ability to taste
183
What are the three (paired) salivary glands?
Parotid
Submandibular
Sublingual
184
Where is the parotid gland located on each side of the face?
Anterior to the ear wrapping around the posterior border of the ramus of the mandible
185
How many ducts does the parotid gland have?
1
186
Where does the duct of the parotid gland travel?
Superficial to the masseter muscle and then pierces the buccinator muscle to enter the vestibule of the mouth opposite the crown of the upper second molar
187
What shape is the submandibular gland likened to?
A horseshoe
188
What parts are the submandibular gland separated into?
The intraoral and the extraoral parts
189
Where can the extraoral part of the submandibular gland be palpated?
Just below the lateral aspect of the body of the mandible
190
Where is the intraoral part of the submandibular gland located?
Inferior to the floor of the mouth mucosa
191
How many glands does each submandibular gland have?
1
192
Where does the duct of the submandibular gland open at?
The sublingual papilla on each side on the floor of the mouth behind the lower incisor
193
What are the smallest of the main salivary glands?
The sublingual glands
194
Where are the sublingual glands located?
between the tongue and the mandible
195
Fill in the blanks:
The sublingual glands have ________ ductule(s) that run along the ____________ ______.
Multiple (15-20)
Sublingual fold
196
Apart from the main salivary glands, where are other tiny salivary glands found? What are they called?
On the muscosa of the tongue, palettes and lips
Minor salivary glands
197
Which cranial nerves are involved in stimulating salivation?
VII - facial nerve
IX - glossopharyngeal nerve
198
What type of Innervation do the facial and glossopharyngeal nerves cause at the salivary glands?
Secretomotor innervation
199
What part of the nervous system controls the salivary glands?
The autonomic - specifically parasympathetic - nervous system
200
What other nerve do the secretomotor fibres often run with on their way to the salivary glands?
The trigeminal nerve (cranial nerve V)
201
Which ganglia have no synapses - only cell bodies?
Sensory ganglia
202
What is an example of a sensory ganglion?
The trigeminal ganglion
203
Which cranial nerve supplies the parotid gland with sensorimotor Innervation?
The glossopharyngeal nerve
204
Which branch of the glossopharyngeal nerve gives branches for the parotid gland?
The tympanic nerve
205
What is the nerve pathway to stimulate the parotid gland?
Glossopharyngeal nerve —> tympanic nerve —> tympanic plexus —> lesser petrosal nerve —> auriculotemporal nerve
206
Where does the tympanic nerve run?
The middle ear cavity in the temporal bone
207
Where is the tympanic plexus located?
In the medial wall of the middle ear cavity
208
Where does the lesser petrosal nerve run?
Out of the temporal bone into the cranial cavity, runs under the brain and out via the foramen ovale to the otic ganglion
209
Which nerves run through the foramen ovale?
The mandibular and lesser petrosal nerve
210
At which point in the neural pathway to the parotid gland, do the nerve fibres change from preganglionic to postganglionic?
At the otic ganglion
211
What nerve do the postganglionic nerve fibres join after the otic ganglion to reach the parotid gland?
Which nerve do they form?
Fibres of the mandibular nerve
The auriculotemporal nerve
212
Which nerve fibres of the auriculotemporal supply the parotid gland?
Only the nerve fibres from the glossopharyngeal nerve. The nerve fibres of the mandibular nerve (from the trigeminal nerve) carry on to supply other areas.
213
Where does the sympathetic Innervation of the parotid gland come from?
The superior cervical ganglion
214
How does the superior cervical ganglion inhibit the secretion of saliva?
By sending signals via the endothelial tissues to the parotid gland
215
Where does the submandibular gland sit?
Immediately posterior to the body of the mandible, anterior to where the body meets the mandible’s ramus
216
Where does the duct of the submandibular gland run?
Anteriomedially to the small papilla on the floor of the mouth
217
Fill in the blank
Both the submandibular and sublingual glands receive their secretomotor Innervation from the ________ nerve.
Facial
218
The sensory fibres of which nerve supply the posterior two thirds of the tongue?
Facial nerve
219
Which nerves are involved in the secretomotor fibres path to the submandibular and sublingual glands?
Facial nerve —> chorda tympani —> lingual nerve —> submandibular ganglion
220
Where does the chorda tympani run?
Through the middle ear cavity of the temporal bone out of the skull medially to the ramus of the mandible
221
What fossa does the chorda tympani leave the skull into?
The infratemporal fossa
222
Which branch of the mandibular nerve do the secretomotor fibres, for submandibular and sublingual gland innervation, run with?
Lingual nerve
223
Where do the preganglionic fibres for innervating the submandibular and sublingual nerve synapse with the postganglionic fibres?
At the submandibular ganglion
