Salivary glands

Salivary glands. They are the glands attached to the mouth, their secretion being saliva. The amount of saliva excreted in 24 hours varies between 1000 and 1500 milliliters and its functions are to maintain the humidity of the mucosa of the oral cavity to prevent its desiccation, to moisten food to facilitate its chewing and swallowing due to the dissolution of the substances, for example. which allows you to capture their flavor. Saliva contains two oaks (ptyalin and maltase), which act in the enzymatic digestion of starch and maltase, and also helps in the mechanical cleaning of the teeth .

Summary

[ disguise ]

• 1 Acini of the glands
• 2 Classification of salivary glands
• 3 minor glands
  • 1 Labial glands
  • 2 Oral glands
  • 3 Palatine glands
  • 4 Lingual glands
• 4 Major glands
  • 1 Parotid gland
  • 2 Shape
  • 3 Relationships
  • 4 Extremities
  • 5 Borders
  • 6 Intraparotid relations
• 5 Parotid duct
• 6 Submandibular gland
  • 1 Form
  • 2 Relationships
  • 3 Extremities
  • 4 Borders
  • 5 Excreta driver
  • 6 Anatomical constitution
• 7 Sublingual gland
  • 1 Form
  • 2 Relationships
  • 3 Borders
  • 4 Anatomical constitution
• 8 Source

acini of the glands

The acini of the salivary glands are tubulo-alveolar and merocrine and according to the type of secretion they are divided into: serous, mucous, and mixed, with serous predominance. The acini are grouped to form an important glandular segment, the primary lobule, the union of some primary lobules gives rise to the secondary lobule and the group of these constitutes the gland.

Classification of salivary glands

According to the size of the salivary glands, they are divided into two groups: major and minor.

minor glands

The minor salivary glands are located on the walls of the mouth and according to their location they are called: labial, buccal, palatine, lingual.

labial glands

They form a plane in the labial region, they are found between the mucosa and the muscular layer of both lips, they are pressed together, if you pass the pad of a finger over the labial mucosa, they are perceived in the form of small hard protruding masses. and irregular, they can be the seat of cysts and tumors that project into the labial mucosa.

oral glands

They are found in the thickness of the buccinator muscle on the outside of it, their ducts pierce the muscle and open into the vestibule , the glands that are located in the vicinity of the parotid duct are called molars.

Palatine glands

They are located in the palatine vault , on both sides of the median line, between the mucosa and the periosteum, they reach their maximum development in the posterior part where they form a continuous and thick mass, the mouth of the excretory ducts becomes evident when they are If you have a subject with the mouth open for some time, then small drops of saliva are observed on the palatal vault.

Lingual glands

They are found in the thickness of the tongue, grouped topographically in the proximity of the vallate and foliate papillae, in the posterior part of the edges of the tongue and at the apex or lingual vertex.

major glands

The major salivary glands are: the parotid, the submandibular and the sublingual, they are located near the oral cavity following an open curve forward and upward.

parotid gland

What does it mean for: around and others: ear . In the most voluminous one, they are located behind the mandibular ramus and in front of the sternocleidomastoid, they have a yellowish gray color, their surface is lobed, they have a variable weight, on average 25 grams.

Shape

The gland is irregularly prismatic triangular, it has three faces: anterior, lateral and posterior; three edges: anterior, posterior and medial or deep; and two upper and lower extremities.

Relations

The parotid is included in the parotid cell and adapts to its shape; its relationships are in correspondence with structures that form the walls of the cell immediately and others further away.

Anterior surface: it is grooved in the vertical direction, relating lateromedially to the posterior edge of the masseter, posterior edge of the medial pterygoid mandibular ramus, and interpterygoid fascia.

Posterior face: it is oriented backwards, downwards and inwards and corresponds from outside to inside, with the anterior edge of the sternocleidomastoid, to the posterior belly of the digastric , to the stylohyoid , and to the styloglossus , united by the lateral extension of the membrane external pharyngeal ; Behind these structures are the internal carotid, internal jugular, spinal vagus, hypoglossus, and upper cervical sympathetic ganglia. Two processes project from the posterior surface of the gland: one between the sternocleidomastoid and the digastric, the other between the digastric and the stylohyoid process.

Lateral face: it is flattened or slightly domed, covered by the cervical fascia, which extends from the masseteric fascia to the sternocleidomastoid fascia. Outside the fascia, there is the subcutaneous cellular tissue and the skin .

Extremities

Upper extremity: presents the temporomandibular joint in front and the external acoustic meatus behind .

Lower extremity: it is located at the level of the gonion of the mandible and is separated from the submandibular gland by a condensation of the cervical fascia extended from the gonial process to the anterior edge of the sternocleidomastoid and by the stylomandibular ligament.

Borders

The posterior one is related to the anterior edge of the sternocleidomastoid, the anterior one is attached to the masseteric facia, from this edge the parotid duct emerges, the medial edge is related to the sphenomandibular ligament and the pharynx.

Intraparotid relations

In the thickness of the parotid are:

• The external carotid, which runs from bottom to top, with its temporal, superficial and maxillary terminals.
• The retromandibular vein , which is formed in its upper extremity by the union of the superficial temporal vein and the maxillary vein and descends vertically to the lower extremity.
• The temporal atrial nerve enters the gland through its anterior surface and heads upward and exits through the upper extremity.
• The facial nerve enters the gland through its posterior surface and in its thickness divides into two terminal branches: cervicofacial and temporofacial. The facial vein is located outside the retromandibular vein and divides the gland into two superficial and deep lobes.

parotid duct

It carries saliva from the gland to the oral cavity. It is approximately 4 centimeters long and 3 centimeters thick, and is flattened. It emerges at the anterior edge of the gland above its middle part, it heads forward, entering a split of the masseteric facia upon reaching the anterior edge of the masseter, the duct heads inward, contouring the adipose body of the mouth ( Bichat), pierces the buccinator and opens in the mouth in front of the neck of the maxillary first or second molar. The mucosa of the vestibule, where the duct opens, sometimes has a small eminence called the parotid papilla. The duct in its path is located in the masseteric and genian regions and from back to front it approaches the zygomatic arch, its path is varied and can be rectilinear, arched, S-shaped.

In its path along the lateral surface of the masseter, a small glandular mass derived from the parotid is sometimes found, called the accessory parotid .

With all the organs whose functions are very active, it is richly irrigated and innervated, it receives its arterial vessels from the posterior auricular, occipital, anterior auricular, superficial temporal, transverse face and directly from the trunk of the external carotid.

The venules run along with the arteries through the interlobular septa and form larger veins, which end their venous drainage in the retromandibular.

Lymphatic: lymphatic drainage is carried out to the superficial and deep parotid lymph nodes, and from these the efferent vessels go to the supercial cervicals of the external jugular and mainly to the chain of lymph nodes of the internal jugular.

Nerves: the innervation of the parotid has three origins:

• Auriculotemporal which receives from the optic ganglion , the postganglionic fibers for the gland, the preganglionic fibers correspond to the glossopharyngeal.
• Auricular branch of the cervical plexus, carries sensory fibers to the lower part of this region, skin and connective tissue .
• Sympathetic nerve: sympathetic fibers reach the gland through the periadventitial flexuses of the arteries that supply it.

Submandibular gland

It is located in the suprahyoid region, in the depression between the jaw on the outside and the suprahyoid muscles and the base of the tongue on the inside.

Shape

The gland is contained in the submandibular cell, which is an osteo-musculo-facial behavior and adopts the shape of the cell, which is why it has three faces: deep medial, superolateral and inferolateral; three edges: superior, inferior and lateral and two extremities anterior and posterior.

Relations

The medial face is flattened and is related to the digastric and stylohyoid, the hypoglossal nerve , lingual vein , facial artery , mylohyoid and hyoglossus muscles , inside the latter with the lingual artery, from this face a well-individualized anterior extension originates. , about 20 millimeters long, of which it heads forward, placing itself between the hyoglossus and mylohyoid muscles, and comes into contact with the sub-lingual gland.

Superolateral aspect: In its posterior part it contacts the medial pterygoid and in front with the submandibular fossa of the mandible, the mylohyoid vessels and nerves and is also related to the submandibular lymph nodes, facial artery and submentor branch.

Inferolateral face: It is the most external of the three and corresponds from the surface to the depth; Branches of the facial nerve of the cervical plexus and facial veins are also found with the skin, subcutaneous cellular tissues, platysma and fascia.

Extremities

Anterior limb: It is rounded in appearance and applies to the anterior belly of the digastric and mylohyoid muscles. Posterior limb: It is located close to the parotid, separated from it by the fibrous fascicle described in the parotid; and inside it is related to the middle pharyngeal constrictor.

Borders

Upper border: Corresponds in front to the mylohyoid, behind to the mucosa of the alveolar-lingual sulcus, between the mucosa and the gland the lingual nerve penetrates the region, leaving the submandibular ganglion below the nerve.

Lateral border: located at the level of the lower border of the jaw.

Lower edge: It is located a few millimeters below the hyoid bone .

Excreta driver

The excretory conductor (Wharton), has a length of 4 to 5 centimeters and a thickness of 3 to 4 millimeters, it is a thin-walled, whitish duct. It emerges on the deep surface of the gland through the union of two collectors and heads forward and inward, crossing above the mylohyoid and inside the sublingual gland until it reaches the sublingual curuncula, located at the base of the lingual frenulum, where it opens. in the oral cavity through the umbilical ostium (bordeu). An important relationship in its journey is that the lingual nerve is located above the canal and from back to front it crosses it on the outside and below to enter the tongue .

anatomical constitution

The submandibular gland is made up of a connective stroma , where the acini , primary and secondary lobes are identified , the volume and number of the lobes is very variable and they are joined by fibrovascular pedicles, each gland consists of 10 lobes.

Vessels: The arterial branches directly and indirectly come from the facial through its submentor and ascending palatine collaterals. The main artery that reaches through its deep face originates from the facial vein; the veins flow into the facial and submental arteries.

Lymphatic: Lymphatic drainage is towards the submandibular lymph nodes .

Nerves: The parasympathetic nerves destined for the gland reach the submandibular ganglion through the chorda tympani and the sympathetic nerve fibers through the flexuses located in the adventitia of the arteries.

sublingual gland

It is the most anterior of the major salivary glands, located on the floor of the mouth, inside the jaw and on each side of the mental spine . It is the smallest of the glands, weighing 3 grams.

Shape

The gland is elongated and flattened in the transverse direction, its major axis being 25 to 30 millimeters, its height 10 to 12 millimeters and its thickness 6 to 8 millimeters. It has two superficial and deep faces; two edges: upper and lower and two posterior and anterior extremities.

Relations

The gland, unlike the parotid and submandibular, is not located in a true cell, being included in an atmosphere of loose connective tissue.

Superficial or lateral face: It is related to the sublingual fossa of the mandible and the line of insertion of the mylohyoid.

Deep or medial face: it is related to the lingual genioglossus and inferior longitudinal muscles, and between them and the gland is the lingual nerve and the excretory duct of the submandibular.

Borders

Inferior border: corresponds to the groove formed when the mylohyoid and genioglossus muscles separate.

Upper edge: it is thicker and contacts the mucosa of the alveololingual groove, constituting the sublingual fold.

Posterior end: is related to the anterior extension of the submandibular.

Anterior end: the muscles that originate from it are related to the mental spine: Genioglossus and Geniohyoid.

anatomical constitution

It is a mixed gland with serous, mucosal and mixed acinus, with mucosal predominance.

Excretory ducts: its extra glandular excretory ducts behave, as if there were a group of independent glands, their number variable (18 to 20 prives), these ducts empty into the sublingual fold, the greater sublingual duct is described, which originates in the posterior part of the gland and empties together with the submandibular excretory duct into the umbilical ostium .

Vessels : The arteries destined for the glands come from the lingual and submental and the veins go to the deep lingual.

Lymphatic: flows into the submandibular lymph nodes.

Nerves : The motor nerves of the parasympathetic type reach the submandibular ganglion through the chorda tympani and from this, the postganglionic fibers reach the gland through the lingual and the sympathetic innervation reaches it similar to the other glands.