tongue

what is the tongue

the tongue is a muscular organ which bulges up from the floor of the mouth

what does the posterior one-thirds of the tongue form?

it forms the anterior wall of the oropharynx

what are the functions of the tongue?

1. aids in chewing

2. swallowing

3. speech

4. taste

what composes the dorsum of the mouth?

1. palatine part

2. pharyngeal part

what is the palatine part of the mouth composed of?

it includes the anterior two-thirds. it is covered by the mucous membrane, containing lingual papillae

what is the embryological development of the palatine part of the tongue?

it develops from the 1st branchial arch

what innervates the palatine part of the tongue?

it is innervated by the mandibular nerve

what is the pharyngeal part of the tongue composed of?

it includes the posterior one-thirds of the tongue. it is covered by mucous membrane

why does the pharyngeal part of the tongue appear nodular and smooth?

due to the presence of underlying lymphoid follicles, which form the lingual tonsils

what is the embryological development of the pharyngeal part of the tongue?

it develops from the 3rd branchial artery

what innervates the pharyngeal part of the tongue?

it is innervated by the glossopharyngeal nerve

where does the pharyngeal part of the tongue extend into?

it extends backwards and upwards towards the epiglottis as the medial and lateral glossopharyngeal folds

what are the palatine and pharyngeal parts of the tongue separated by?

a V-shaped sulcus, which is called the sulcus terminalis

what direction is the apex of this sulcus directed at, and what depression marks it?

it is directed backwards and is marked by a depression which is called the foramen caecum

what is the foramen caecum the original site for?

it is the original, or embryonic, site of the thyroid rudiment and the upper end of the thyroglossal duct

what runs from the foramen caecum to the tip of the tongue?

a shallow median groove

what are the lingual papillae?

they are epithelial projections from the mucous membrane, covering the anterior two-thirds of the tongue, and they vary based on shape and arrangement.

what are the 3 types of lingual papillae?

1. filiform papillae

2. fungiform papillae

3. vallate or circumvallate papillae

filiform papillae

• forms the majority of the lingual papillae

• spread around the dorsum of the tongue and margins of the anterior two-thirds of the tongue

• they are in the form of pointed projections, which are arrange in parallel rows in front of the sulcus terminalis

• they contain no taste buds

fungiform papillae

• larger than the filiform papillae but less numerous

• appear in the form of bright red spots, which mainly present in the tip and sides. they are less present on the dorsum

• each papillae has a narrow base and an expanded, knob-like free surface, resembling a mushroom.

• they contain tastebuds

vallate papillae

• largest of the lingual papillae

• 6-12 in number

• arranged in one row directly anterior to the sulcus terminalis

• each papillae is surrounded by a deep trench, known as a vallum, containing a great number of taste buds

what is the inferior surface of the tongue covered by?

it is covered by mucous membrane, which is thin and smooth

where is the tongue attached to the floor of the mouth?

at the midline, it is attached to the floor by a thin fold called the frenulum linguae

what is closely located to the frenulum linguae?

the sublingual papilla

what can you see on each side of the frenulum through the thin mucous membrane?

the deep (profunda) lingual vein

more laterally from the deep lingual vein, what can be found?

a fringed mucosal fold known as the fimbriated fold

what opening does the sublingual papillae carry?

the opening of the submandibular duct

what extends posterior-laterally from the frenulum linguae?

the sublingual fold, which overlies the sublingual gland

what is the smallest of the three salivary glands?

the sublingual gland

where does the sublingual gland lie?

It lies below the tongue, resting on the upper surface of the mylohyoid muscle, and is covered by the mucous membrane of the floor of the mouth. Laterally, it is related to the sublingual fossa of the mandible

what is superior to the sublingual gland?

superiorly, it is covered by mucous membrane of the floor of the mouth

the mucosa in the floor of the mouth is raised to form what?

the sublingual fold, which is visible as a ridge besides the frenulum

what does the sublingual gland rest on inferiorly?

it rests on the mylohyoid muscle

what dos the sublingual gland lie against laterally?

lies against the sublingual fossa of the mandible

what does the sublingual gland lie next to medially?

it lies next to the

what does the genioglossus muscle separate the sublingual gland from?

from the

what does the submandibular duct contain?

it has numerous small accessory ducts that open into the floor of the mouth over the sublingual fold

what is the blood supply of the sublingual gland region?

it is supplied by the sublingual artery branch from the lingual artery

what innervates the sublingual gland region?

• the sensory supply is from the lingual nerve

• parasympathetic is supplied by the submandibular ganglion

• sympathetic is supplied by the periarterial plexus

what divides the muscles into right and left halves?

a median fibrous septum