The parotid duct, or Stensen duct, is a salivary duct. It is the route that

saliva Saliva (commonly referred to as spit) 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 DNA can be ...

takes from the major salivary gland, the parotid gland, into 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 ...

Structure

The parotid duct is formed when several interlobular ducts, the largest ducts inside the parotid gland, join. It emerges from the parotid gland. It runs forward along the lateral side of the masseter muscle for around 7 cm. In this course, the duct is surrounded by the

buccal fat pad The buccal fat pad (also called Bichat’s fat pad, after Xavier Bichat, and the buccal pad of fat) is one of several encapsulated fat masses in the cheek. It is a deep fat pad located on either side of the face between the buccinator muscle and se ...

. It takes a steep turn at the border of the masseter and passes through the buccinator muscle, opening into the

vestibule 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 ...

, the region of the mouth between the cheek and the

gum Gum may refer to: Types of gum * Adhesive * Bubble gum * Chewing gum * Gum (botany), sap or other resinous material associated with certain species of the plant kingdom ** Gum arabic, made from the sap of ''Acacia senegal'', an Old World tree s ...

s, at the parotid papilla, which lies across the second Maxillary (upper) molar tooth. The buccinator acts as a valve that prevents air forcing into the duct, which would cause

pneumoparotitis Pneumoparotitis (also termed pneumosialadenitis wind parotitis, surgical mumps, or anaesthesia mumps), is a rare cause of parotid gland swelling which occurs when air is forced through the parotid (Stensen) duct resulting in inflation of the duct. ...

. Running along with the duct superiorly is the

transverse facial artery The transverse facial artery is an artery that branches from the superficial temporal artery and runs across the face. Course The transverse facial artery is given off from the superficial temporal artery before that vessel leaves the parotid glan ...

and upper buccal nerve; running along with the duct inferiorly is the lower buccal nerve. The exit of the parotid ducts can be felt as small bumps (

papillae Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

) on both sides of the mouth, and are usually positioned next to the maxillary second molars.

Relations

The parotid duct lies close to the buccal branch of the facial nerve (VII). It is also close to the

Clinical significance

Blockage, whether caused by salivary duct stones or external compression, may cause pain and swelling of the parotid gland ( parotitis). Koplik's spots which are pathognomonic of

measles Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than , cough, ...

are found near the opening of the parotid duct. The parotid duct may be cannulated by inserting a tube through the internal orifice in the

. Dye may be injected to allow for imaging of the parotid duct.

History

The parotid duct is named after

Nicolas Steno Niels Steensen ( da, Niels Steensen; Latinized to ''Nicolaus Steno'' or ''Nicolaus Stenonius''; 1 January 1638 – 25 November 1686Niels Stensen Niels Steensen ( da, Niels Steensen; Latinization (literature), Latinized to ''Nicolaus Steno'' or ''Nicolaus Stenonius''; 1 January 1638 – 25 November 1686

, a

Danish Danish may refer to: * Something of, from, or related to the country of Denmark People * A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark * Culture of Denmark * Danish people or Danes, people with a Danish ance ...

anatomist (albeit best known as a geologist) credited with its detailed description in 1660. This is where the alternative name "Stensen duct" originates from.

Additional images

File:Gray1200.png, Outline of side of face, showing chief surface markings. File:Parotid-interlobular duct.JPG, Microscopic slide of a human interlobular duct. File:Parotid-striated duct.JPG, Microscopic slide of a human striated duct. File:Parotid duct papillae.JPG, The left papilla (soft tissue protuberance at the exit) of the parotid duct is clearly visible on the cheek in the right of the photo. File:Slide6rrrr.JPG, Parotid duct File:Slide7yyyy.JPG, Parotid duct File:Slide3BBB.JPG, Parotid duct

References

External links

Diagram at MSU
* - Parotid duct injuries * {{Authority control Glands of mouth Saliva