The submandibular duct (also Wharton's duct or historically submaxillary duct) is one of the salivary excretory ducts. It is about 5 cm long, and its wall is much thinner than that of the

parotid duct The parotid duct or Stensen duct is a salivary duct. It is the route that saliva takes from the major salivary gland, the parotid gland, into the mouth. Structure The parotid duct is formed when several interlobular ducts, the largest ducts insid ...

. It drains

saliva Saliva (commonly referred as spit or drool) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which ...

from each bilateral

submandibular gland The paired submandibular glands (historically known as submaxillary glands) are major salivary glands located beneath the floor of the mouth. In adult humans, they each weigh about 15 grams and contribute some 60–67% of unstimulated saliva sec ...

and

sublingual gland The sublingual gland (''glandula sublingualis'') is a seromucous polystomatic exocrine gland. Located underneath the oral diaphragm (''diaphragma oris''), the sublingual gland is the smallest and most diffuse of the three major salivary glands of ...

to the sublingual caruncle in the

floor of the mouth In human anatomy, the mouth is the first portion of the alimentary canal that receives food and produces saliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth. In addition to its primary role as the beginning ...

Structure

270px, Picture of the mouth showing the sublingual caruncle and related anatomical structures The submandibular duct arises from deep part of

, a

salivary gland The salivary glands in many vertebrates including 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 min ...

. It begins by numerous branches from the superficial surface of the gland, and runs forward between the mylohyoid,

hyoglossus The hyoglossus is a thin and quadrilateral extrinsic muscle of the tongue. It originates from the hyoid bone; it inserts onto the side of the tongue. It is innervated by the hypoglossal nerve (cranial nerve XII). It acts to depress and retract th ...

, and

genioglossus The genioglossus is one of the paired extrinsic muscles of the tongue. It is a fan-shaped muscle that comprises the bulk of the body of the tongue. It arises from the mental spine of the mandible; it inserts onto the hyoid bone, and the bottom o ...

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

s. It then passes between the sublingual gland and the genioglossus and opens by a narrow opening on the summit of a small papilla (the "sublingual caruncle") at the side of the

frenulum of the tongue The frenulum (or frenum) of the tongue, tongue web, lingual frenulum, frenulum linguae, or fraenulum is a small fold of mucous membrane extending from the floor of the mouth to the midline of the underside of the human tongue. Development The t ...

. It lies superior to lingual and

hypoglossal nerve The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a cranial nerve that innervates all the extrinsic and intrinsic muscles of the tongue except for the palatoglossus, which is innervated b ...

Variation

The submandibular duct may be duplicated on one side or both sides, creating an accessory submandibular duct. Rarely, it may not perforate into the

mouth A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also t ...

Function

The submandibular ducts drain

from the submandibular and

s to the sublingual caruncles in the floor of the mouth

Clinical significance

Sialolithiasis

The submandibular duct may be affected by stones, known as

sialolithiasis Sialolithiasis (also termed salivary calculi, or salivary stones) is a crystallopathy where a calcified mass or ''sialolith'' forms within a salivary gland, usually in the duct of the submandibular gland (also termed " Wharton's duct"). Less commo ...

. These may grow large, requiring

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

to remove. Simple

palpation Palpation is the process of using one's hands to check the body, especially while perceiving/diagnosing a disease or illness. Usually performed by a health care practitioner, it is the process of feeling an object in or on the body to determine ...

may be used to identify the location of any stones before surgery.

Imperforate

Rarely, the submandibular duct may not perforate into the

Surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

may be used to repair this

birth defect A birth defect is an abnormal condition that is present at birth, regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can range from mild to severe. Birth de ...

Drooling

The exit of the submandibular gland into the mouth may be realigned in patients who drool. This redirects the exiting saliva away from the vestibule and the

lips The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

. This

has a fairly high success rate. Rarely, the submandibular gland may need to be removed on one or both sides.

History

The submandibular duct was initially described by the English

anatomist Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

Thomas Wharton ( 1614-73) and is sometimes referred to by his name.

References

External links

* * {{Authority control Glands of mouth Saliva