Exocrine glands are glands that secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate and mucous. Exocrine glands are one of two types of glands in the human body, the other being endocrine glands, which secrete their products directly into the bloodstream. The liver and pancreas are both exocrine and endocrine glands; they are exocrine glands because they secrete products—bile and pancreatic juice—into the gastrointestinal tract through a series of ducts, and endocrine because they secrete other substances directly into the bloodstream. Exocrine sweat glands are part of the integumentary system; they have eccrine and apocrine types.
Saliva 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, enzymes, and antimicrobial agents.
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, as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous, or seromucous (mixed).
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 mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches. There are also two other types of salivary glands; they are submandibular and sublingual glands. Sometimes accessory parotid glands are found close to the main parotid glands.
The paired submandibular 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 secretion; on stimulation their contribution decreases in proportion as parotid gland secretion rises to 50%. The average length of the normal adult human submandibular salivary gland is approximately 27 mm, while the average width is approximately 14.3 mm.
The sublingual gland is a seromucous polystomatic exocrine gland. Located underneath the oral diaphragm, the sublingual gland is the smallest and most diffuse of the three major salivary glands of the oral cavity, with the other two being the submandibular and parotid. The sublingual gland provides approximately 3-5% of the total salivary volume.
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.
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 of the submental triangle. It elevates the hyoid bone and the tongue, important during swallowing and speaking.
The frenulumof 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.
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 caused by local trauma. If small and asymptomatic further treatment may not be needed, otherwise minor oral surgery may be indicated.
Sialadenitis (sialoadenitis) is inflammation of salivary glands, usually the major ones, the most common being the parotid gland, followed by submandibular and sublingual glands. It should not be confused with sialadenosis (sialosis) which is a non-inflammatory enlargement of the major salivary glands.
Sialolithiasis is a crystallopathy where a calcified mass or sialolith forms within a salivary gland, usually in the duct of the submandibular gland. Less commonly the parotid gland or rarely the sublingual gland or a minor salivary gland may develop salivary stones.
In anatomy and physiology, a duct is a circumscribed channel leading from an exocrine gland or organ.
The Stafne defect is a depression of the mandible, most commonly located on the lingual surface. The Stafne defect is thought to be a normal anatomical variant, as the depression is created by ectopic salivary gland tissue associated with the submandibular gland and does not represent a pathologic lesion as such. This cavity is commonly observed on panoramic radiograph.
A salivary duct is a duct which brings saliva from a salivary gland to part of the digestive tract. In human anatomy there are:
Salivary gland tumours, also known as mucous gland adenomas or neoplasms, are tumours that form in the tissues of salivary glands. The salivary glands are classified as major or minor. The major salivary glands consist of the parotid, submandibular, and sublingual glands. The minor salivary glands consist of 800 to 1000 small mucus-secreting glands located throughout the lining of the oral cavity. Patients with these types of tumours may be asymptomatic.
Mouth infections, also known as oral infections, are a group of infections that occur around the oral cavity. They include dental infection, dental abscess, and Ludwig's angina. Mouth infections typically originate from dental caries at the root of molars and premolars that spread to adjacent structures. In otherwise healthy patients, removing the offending tooth to allow drainage will usually resolve the infection. In cases that spread to adjacent structures or in immunocompromised patients, surgical drainage and systemic antibiotics may be required in addition to tooth extraction. Since bacteria that normally reside in the oral cavity cause mouth infections, proper dental hygiene can prevent most cases of infection. As such, mouth infections are more common in populations with poor access to dental care or populations with health-related behaviors that damage one's teeth and oral mucosa. This is a common problem, representing nearly 36% of all encounters within the emergency department related to dental conditions.
The sublingual space is a fascial space of the head and neck. It is a potential space located below the mouth and above the mylohyoid muscle, and is part of the suprahyoid group of fascial spaces.
Salivary gland diseases (SGDs) are multiple and varied in cause. There are three paired major salivary glands in humans: the parotid glands, the submandibular glands, and the sublingual glands. There are also about 800–1,000 minor salivary glands in the mucosa of the mouth. The parotid glands are in front of the ears, one on side, and secrete mostly serous saliva, via the parotid ducts, into the mouth, usually opening roughly opposite the second upper molars. The submandibular gland is medial to the angle of the mandible, and it drains its mixture of serous and mucous saliva via the submandibular duct into the mouth, usually opening in a punctum in the floor of mouth. The sublingual gland is below the tongue, on the floor of the mouth; it drains its mostly mucous saliva into the mouth via about 8–20 ducts, which open along the plica sublingualis, a fold of tissue under the tongue.
A salivary gland fistula is a fistula involving a salivary gland or duct.
