The tongue Flashcards
What are 5 functions of the tongue?
- Articulation
- Mastication
- Deglutition
- Taste
- Oral cleaning
How many nerves contribute to the innervation of the tongue?
Five
What is the significance of the Foramen cecum?
Site in the embryo where the epithelium invaginated to form the thyroid gland
Describe the posterior 1/3 of the tongue.
No papillae, surface is nodular- lymphoid tissue.
What are lingual papillae?
Elevated structures of specialised mucosa
filiform, fungiform, circumvallate
What types of papillae have taste buds?
Fungiform, circumvallate, foliate
Describe filiform lingual papillae.
- Most numerous
- Gives velvety texture
- No taste buds
Describe fungiform papillae.
- Globular (mushroom shaped)
- Numerous at apex and sides
- Contain tastebuds
Describe circumvallate papillae.
- Large
- Surrounded by a circular groove
- anterior to sulcus terminalis in a V
- Contain taste buds
Describe foliate lingual papillae.
- Linear vertical folds of mucosa on the lateral surface near sulcus terminalis
- Have taste buds
Where else in the mouth are tastebuds scattered?
- Oral surface of the soft palate
- Posterior wall of pharynx
- Epiglottis
What is the lingual fraenum?
- Median mucosal fold that anchors the tongue to the floor of the mouth
What is the sublingual caruncle?
The opening of the Wharton’s and Bartholin’s duct- at the base of the lingual fraenum.
What are plica fimbriata?
A fold on the ventral surfacce of the tongue with finger like projections
What divides the tongue into halves?
The median septum- demarcated by the median lingual sulcus.
What are the 4 pairs of intrinsic tongue muscles? (planes)
- Vertical
- Transverse
- Superior longitudinal
- Inferior longitudinal
What do the intrinsic tongue muscles do?
Change the shape of the tongue ie lengthening and shortening, curling, flattening and rounding
Where do the vertical tongue muscles run and what is their action?
Vertically from the dorsal to the ventral surface- flatten and broaden
Where do the transverse tongue muscles run and what is their action?
From median septum to lateral surface- narrow and elongate the tongue
Where do the superior longitudinal tongue muscles run and what is their action?
Run superiorly longitudinally from base to apex- shorten the tongue and turns its tip and edges upwards
Where do the inferior longitudinal tongue muscles run and what is their action?
Run inferiorly longitudinally from base to apex- shorten the tongue and turn its tip and edges downwards.
What do the extrinsic tongue muscles do?
Act to move the tongue bodily
What are the four pairs of extrinsic tongue muscles?
- Hyoglossus
- Styloglossus
- Genioglossus
- Palatoglossus
What tongue muscle has a different innervation and what is it?
The palatoglossus is innervated by the vagus nerve through a pharyngeal plexus.
What is the action of the styloglossus muscle?
- Elevate the tongue moving it posteriorly (important in early phases of swallowing)
What is the action of the hyoglossus muscle?
Depress the tongue
What is the action of the genioglossus muscle and what is special about this muscle?
- Protrusion, bilateral activity helps to depress the tongue
- Fan shaped muscle that makes up the bulk of the tongue
Where is the palatoglossus muscle located and what does it form?
Between the soft palate and the tongue, forms the anterior faucial pillars.
What is the action of the palatoglossus muscle?
Elevates the base of the tongue and helps to separate the oral cavity from the pharynx
Describe the special sensation nerve supply for the tongue.
most posterior part - vagus N
posterior 1/3- glossopharyngeal N
anterior 2/3- facial N
Describe the general sensation nerve supply for the tongue.
most posterior part- vagus N
posterior 1/3- glossopharyngeal N
anterior 2/3- Trigeminal N via lingual N
Outline the motor nerve supply of the tongue?
The hypoglossal N except the palatoglossus- Vagus N
What is the arterial supply of the tongue?
The lingual artery- branch of the ECA
What is the venous drainage of the tongue?
The Lingual vein, eventually drains to IJV
Describe the lymphatic drainage for the apex of the tongue.
First drains to primary lymph nodes (submental) and then secondary (submandibular and deep cervical)
Describe the lymphatic drainage for the lateral body of the tongue.
First drains to primary lymph nodes (submandibular ipsilateral) and then secondary (superior deep cervical)
Describe the lymphatic drainage for the centre body of the tongue.
First drains to primary lymph nodes (submandibular bilateral) and then secondary (superior deep cervical)
Describe the lymphatic drainage for the lateral base of the tongue.
First drains to primary lymph nodes (superior deep cervical ipsilateral) and then secondary (inferior deep cervical)
Describe the lymphatic drainage for the central base of the tongue.
First drains to primary lymph nodes (superior deep cervical bilateral) and then secondary (inferior deep cervical)
What are the two modes of clinical examination of the tongue?
- Visual examination
- digital/bidigital palpation
