The paired sublingual glands are major
salivary gland
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary gla ...
s in the
mouth
In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...
. They are the smallest, most diffuse, and the only unencapsulated major salivary glands. They provide only 3-5% of the total salivary volume.
There are also two other types of
salivary
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary glan ...
glands; they are
submandibular
The submandibular ganglion (or submaxillary ganglion in older texts) is part of the human autonomic nervous system. It is one of four parasympathetic ganglia of the head and neck. (The others are the otic ganglion, pterygopalatine ganglion, and cil ...
and
parotid
The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...
glands.
Structure
They lie anterior and superior to the
submandibular gland
The paired submandibular glands (historically known as submaxillary glands) are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion; on stimula ...
and inferior and lateral to the
tongue
The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ...
, as well as beneath the
mucous membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...
of the floor of the mouth. They are bounded laterally by the bone of the mandible and inferolaterally by the
mylohyoid muscle
The mylohyoid muscle or diaphragma oris is a paired muscle of the neck. It runs from the mandible to the hyoid bone, forming the floor of the oral cavity of the mouth. It is named after its two attachments near the molar teeth. It forms the floor ...
. The glands can be felt behind each mandibular canine. Placing one index finger within the mouth and the fingertips of the opposite hand outside it, the compressed gland is manually palpated between the inner and outer fingers.
[Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 156]
The sublingual glands are drained by 8-20 excretory ducts called the ducts of Rivinus.
[Ten Cate's Oral Histology, Nanci, Elsevier, 2013, page 255] The largest of all, the
sublingual duct
The excretory ducts of the sublingual gland are from eight to twenty in number. Of the smaller sublingual ducts (ducts of Rivinus), some join the submandibular duct; others open separately into the mouth, on the elevated crest of mucous membrane (p ...
(of Bartholin) joins the submandibular duct to drain through the
sublingual caruncle. The sublingual caruncle is a small papilla near the midline of the floor of the mouth on each side of the lingual frenum.
Most of the remaining small sublingual ducts (of Rivinus) open separate into the mouth on an elevated crest of mucous membrane, the
plica sublingualis (aka ''sublingual fold''), formed by the gland and located on either side of the
frenulum linguae
The frenulum of tongue or tongue web (also lingual frenulum or frenulum linguæ; also fraenulum) is a small fold of mucous membrane extending from the floor of the mouth to the midline of the underside of the tongue.
Development
The tongue start ...
.
270px, Drawing of an open mouth showing the frenulum linguae & surrounding structures
Microanatomy
The sublingual gland consists mostly of mucous acini capped with
serous demilunes
Serous demilunes, also known as Crescents of Giannuzzi or Demilunes of Heidenhain, are cellular formations in the shape of a half-moon (hence the name "demilune") on some salivary glands.
Serous demilunes are the serous cells at the distal end of ...
and is therefore categorized as a mixed mucous gland with a mucous product predominating.
Striated and
intercalated ducts are also present.
Blood supply
The gland receives its blood supply from the sublingual and submental arteries.
Lymph from the sublingual salivary gland drains into the
submandibular lymph nodes
The submandibular lymph nodes (submaxillary glands in older texts), three to six in number, are lymph nodes beneath the body of the mandible in the submandibular triangle, and rest on the superficial surface of the submandibular gland.
One gland, ...
.
Nerve supply
The
chorda tympani
The chorda tympani is a branch of the facial nerve that originates from the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. It joins the facial nerve (cranial nerve VII) inside the facia ...
nerve (from the
facial nerve
The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of tas ...
via the
submandibular ganglion
The submandibular ganglion (or submaxillary ganglion in older texts) is part of the human autonomic nervous system. It is one of four parasympathetic ganglia of the head and neck. (The others are the otic ganglion, pterygopalatine ganglion, and cil ...
) is
secretomotor
The adjective secretomotor refers to the capacity of a structure (often a nerve) to induce a gland to secrete a substance (usually mucus or serous fluid).
Secretomotor nerve endings are frequently contrasted with sensory neuron endings and motor n ...
and provides parasympathetic supply to the sublingual glands. The path of the nerve is as follows: junction between
pons
The pons (from Latin , "bridge") is part of the brainstem that in humans and other bipeds lies inferior to the midbrain, superior to the medulla oblongata and anterior to the cerebellum.
The pons is also called the pons Varolii ("bridge of Va ...
and
medulla
Medulla or Medullary may refer to:
Science
* Medulla oblongata, a part of the brain stem
* Renal medulla, a part of the kidney
* Adrenal medulla, a part of the adrenal gland
* Medulla of ovary, a stroma in the center of the ovary
* Medulla of t ...
, through
internal acoustic meatus
The internal auditory meatus (also meatus acusticus internus, internal acoustic meatus, internal auditory canal, or internal acoustic canal) is a canal within the petrous part of the temporal bone of the skull between the posterior cranial fossa ...
and
facial canal
The facial canal (''canalis nervi facialis''), also known as the Fallopian canal, is a Z-shaped canal running through the temporal bone of the skull. It runs from the internal acoustic meatus to the stylomastoid foramen. It contains the facial n ...
to
chorda tympani
The chorda tympani is a branch of the facial nerve that originates from the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. It joins the facial nerve (cranial nerve VII) inside the facia ...
, through middle ear cavity, out petrotympanic fissure to join the
lingual nerve
The lingual nerve carries sensory innervation from the anterior two-thirds of the tongue. It contains fibres from both the mandibular division of the trigeminal nerve (CN V3
) and from the facial nerve (CN VII). The fibres from the trigeminal nerv ...
, travels with lingual nerve to synapse at the
submandibular ganglion
The submandibular ganglion (or submaxillary ganglion in older texts) is part of the human autonomic nervous system. It is one of four parasympathetic ganglia of the head and neck. (The others are the otic ganglion, pterygopalatine ganglion, and cil ...
, then
postganglionic
In the autonomic nervous system, fibers from the ganglion to the wikt:effector, effector organ are called postganglionic fibers.
Neurotransmitters
The neurotransmitters of postganglionic fibers differ:
* In the parasympathetic division, neuro ...
fibers travels to the sublingual gland.
Development
The sublingual salivary glands appear in the eighth week of prenatal development, two weeks later than the other two major salivary glands. They develop from
epithelial
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
buds in the sulcus surrounding the sublingual folds on the floor of the mouth, lateral to the developing submandibular gland. These buds branch and form into cords that canalize to form the sublingual ducts associated with the gland. The rounded terminal ends of the cords form
acini
An acinus (; plural, acini; adjective, acinar or acinous) refers to any cluster of cells that resembles a many-lobed " berry," such as a raspberry ('' acinus'' is Latin for "berry"). The berry-shaped termination of an exocrine gland, where t ...
.
[Illustrated Dental Embryology, Histology, and Anatomy, Bath-Balogh and Fehrenbach, Elsevier, 2011, page 136-137]
Clinical significance
Ranula
A ranula is a mucus extravasation cyst involving a sublingual gland and is a type of mucocele found on the floor of the mouth. Ranulae present as a swelling of connective tissue consisting of collected mucin from a ruptured salivary gland caus ...
s are the most common pathologic lesion associated with the sublingual glands.
Additional images
Gray1024.png , Imaging showing the sublingual glands and surrounding structures.
Image:Gray177.png, Mandible. Inner surface. Side view.
File:Slide1vv.JPG, Sublingual gland
File:Slide4ww.JPG, Sublingual gland
File:Slide14ww.JPG, Sublingual gland
References
External links
* - "Oral Cavity: Glands"
* ()
*
Salivary gland infectionsfrom
Medline Plus
MedlinePlus is an online information service produced by the United States National Library of Medicine. The service provides curated consumer health information in English and Spanish with select content in additional languages.
The site brings t ...
Salivary gland cancerfrom
American Cancer Society
The American Cancer Society (ACS) is a nationwide voluntary health organization dedicated to eliminating cancer. Established in 1913, the society is organized into six geographical regions of both medical and lay volunteers operating in more than ...
{{Authority control
Glands of mouth