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 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 ...
, the
parotid gland
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 man ...
, 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
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 man ...
, join. It emerges from the parotid gland. It runs forward along the
lateral
Lateral is a geometric term of location which may refer to:
Healthcare
*Lateral (anatomy), an anatomical direction
*Lateral cricoarytenoid muscle
*Lateral release (surgery), a surgical procedure on the side of a kneecap
Phonetics
*Lateral cons ...
side of the
masseter muscle
In human anatomy, the masseter is one of the muscles of mastication. Found only in mammals, it is particularly powerful in herbivores to facilitate chewing of plant matter. The most obvious muscle of mastication is the masseter muscle, since it ...
for around 7 cm.
In this course, the duct is surrounded by the
buccal fat pad.
It takes a steep turn at the border of the masseter and passes through the
buccinator muscle
The buccinator () is a thin quadrilateral muscle occupying the interval between the maxilla and the mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity.Illustrated Anatomy of the Head ...
, opening into the
vestibule of the mouth, the region of the mouth between the
cheek
The cheeks ( la, buccae) constitute the area of the face below the eyes and between the nose and the left or right ear. "Buccal" means relating to the cheek. In humans, the region is innervated by the buccal nerve. The area between the inside ...
and the
gums, at the parotid papilla, which lies across the second Maxillary (upper)
molar tooth
The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to ...
.
The buccinator acts as a valve that prevents air forcing into the duct, which would cause
pneumoparotitis.
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
The buccal nerve (long buccal nerve) is a nerve in the face. It is a branch of the mandibular nerve (which is itself a branch of the trigeminal nerve) and transmits sensory information from skin over the buccal membrane (in general, the cheek) an ...
; running along with the duct inferiorly is the lower buccal nerve.
The exit of the parotid ducts can be felt as small bumps (
papillae) on both sides of the mouth, and are usually positioned next to the
maxillary second molar
The maxillary second molar is the tooth located distally (away from the midline of the face) from both the maxillary first molars of the mouth but mesial (toward the midline of the face) from both maxillary third molars. This is true only in pe ...
s.
Relations
The parotid duct lies close to the
buccal branch
The buccal branches of the facial nerve (infraorbital branches), are of larger size than the rest of the branches, pass horizontally forward to be distributed below the orbit and around the mouth.
Branches
The ''superficial branches'' run beneath ...
of 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 ...
(VII).
It is also close to 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 ...
.
Clinical significance
Blockage, whether caused by
salivary duct stones or external compression, may cause pain and swelling of the
parotid gland
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 man ...
(
parotitis
Parotitis is an inflammation of one or both parotid glands, the major salivary glands located on either side of the face, in humans. The parotid gland is the salivary gland most commonly affected by inflammation.
Etymology
From Greek παρωτῖ ...
).
Koplik's spots
Koplik's spots (also Koplik's sign) are a prodromic viral enanthem of measles manifesting two to three days before the measles rash itself. They are characterized as clustered, white lesions on the buccal mucosa (opposite the lower 1st & 2nd ...
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
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 ...
.
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 1686[Niels Stensen
Niels Steensen ( da, Niels Steensen; Latinization (literature), Latinized to ''Nicolaus Steno'' or ''Nicolaus Stenonius''; 1 January 1638 – 25 November 1686](_blank ...<br></span></div> (1638–1686), also known as <div class=) , 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 a ...
anatomist
Anatomy () is the branch of biology concerned with the study of the 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 science, having its ...
(albeit best known as a
geologist
A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...
) 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
See also
*
Parotid gland
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 man ...
*
Parotitis
Parotitis is an inflammation of one or both parotid glands, the major salivary glands located on either side of the face, in humans. The parotid gland is the salivary gland most commonly affected by inflammation.
Etymology
From Greek παρωτῖ ...
References
Further reading
*
*
External links
Diagram at MSU* - Parotid duct injuries
*
{{Authority control
Glands of mouth
Saliva