Salivary glands

Salivary glands. They are the glands attached to the mouth, the saliva being its secretion. 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 drying, humeser food to facilitate its chewing and swallowing by dissolving the substances, for what allows to capture the flavor of the same. The saliva contains two oaks (ptialina and maltasa), that act in the enzymatic digestion of the starch and l maltasa, also helps the mechanical cleaning of the teeth .

Summary

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  • 1 Acini of the glands
  • 2 Classification of the salivary glands
  • 3 minor glands
    • 1 Lip glands
    • 2 Mouth glands
    • 3 Palatal glands
    • 4 Lingual glands
  • 4 major glands
    • 1 Parotid gland
    • 2 Form
    • 3 Relationships
    • 4 Extremities
    • 5 Edges
    • 6 Intraparotid relations
  • 5 Parotid duct
  • 6 Submandibular gland
    • 1 Form
    • 2 Relationships
    • 3 Extremities
    • 4 Edges
    • 5 Driver excreta
    • 6 Anatomical Constitution
  • 7 Sublingual gland
    • 1 Form
    • 2 Relationships
    • 3 Edges
    • 4 Anatomical Constitution
  • 8 Source

Gland acini

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

Classification of the 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 situation they are called: labial, buccal, palatine, lingual.

Labial glands

They form a plane in the labial region, they are between the mucosa and the muscular layer of both lips, they are tight with each other, if a finger is passed through the labial mucosa, they are perceived as small hard protruding masses and irregular, they can be the seat of cysts and tumors that project into the labial mucosa.

Buccal glands

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

Palatal glands

They are located in the palatal 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 it has a subject for some time with its mouth open, then small drops of saliva are observed in the palatal vault.

Lingual glands

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

Major glands

The major salivary glands are: the parotid, submandibular and sublingual glands, are located in the vicinity of the oral cavity following an open curve up and up.

Parotid gland

What it means for: around and others: hearing . In the most voluminous, they are located behind the mandibular branch and in front of the sternocleidomastoid, it has a yellowish gray coloration, its surface is lobulated, it has a variable weight, on average 25 grams.

Shape

The gland is irregularly triangular prismatic, 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 the shape of the cell, its relationships are in correspondence with structures that form the cell walls immediately and others more distant.

Anterior face: it is grooved in the vertical direction, later medially relating to the posterior border of the masseter, posterior border of the medial pterygoid mandibular ramus, and interpterygoid fascia.

Posterior face: it is oriented backwards, downwards and inwards and corresponds from the outside to the inside, with the anterior edge of the sternocleidomastoid, the posterior belly of the digastric , the stylohyoid , and the styloglossus , united by the lateral prolongation of the membrane. external pharyngeal ; Behind these structures are the internal carotid, internal jugular, vagus spinal, hypoglossal, upper cervical sympathetic ganglia. Two extensions project from the posterior aspect 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 curved, covered by the cervical fascia, which extends from the maseteric fascia to that of the sternocleidomastoid, outside the fascia, is the subcutaneous cell tissue and skin .

Extremities

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

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

Edges

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

Intraparotid relations

In the parotid thickness are:

  • The external carotid, which runs from bottom to top, with its terminals, temporal, superficial and maxilla.
  • The retromandibular vein, which is formed at its upper extremity by the junction of the superficial temporal and maxillary vein and descends vertically to the lower extremity.
  • The temporal atrial nervepenetrates the gland on its anterior side and is directed upward and exits through the upper limb.
  • The facial nerveenters the gland on its posterior side and its thickness is divided into two terminal branches: cervicofacial and temporofacial. The facial 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 has a length of approximately 4 centimeters and a thickness of 3 centimeters. It is flattened. It emerges at the anterior edge of the gland above its middle part, it is directed forward, entering a splitting of the maseteric facia when it reaches the anterior edge of the masseter, the duct is directed inward, contouring the fatty body of the mouth ( Bichat), pierces the diver and opens in the mouth in front of the neck of the first or second maxillary molar. The mucosaof the vestibule, where the duct is opened, sometimes has a small eminence called the parotid papilla. The duct in its path is located in the masonic and Genian regions and the zygomatic arch is approached from back to front, its path is varied and can be rectilinear, arched, S-shaped.

On its way through the lateral face of the masseter, sometimes a small glandular mass is found, derived from the parotid, called the accessory parotid .

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

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

Lymphatic: Lymphatic drainage is performed to the superficial and deep parotid lymph nodes , and from these the efferent vessels are directed to the superior cervicals of the external jugular and mainly to the lymph node chain of the internal jugular.

Nerves: the innervation of the parotid has three origins:

  • Temporal auricle which receives from the optic ganglion, the postganglionic fibers for the gland, the preganglionic fibers correspond to the glossopharyngeal.
  • Atrial branch of the cervical plexus, carries sensitive fibers for the lower part of this region, skin and connective tissue.
  • Sympathetic nerve The sympathetic fibers reach the gland through the periadventitious flexes 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 a behavior, osteo-muscular-facial, and it takes the shape of the cell and therefore has three faces: deep medial, superolateral and inferolateral; three edges: upper, lower and lateral and two front and back limbs.

Relations

Medial face, is flattened and is related to the digastric and stylohyoid, the hypoglossal nerve , lingual vein , facial artery , mylohyoid and hyoglossal muscle , inside the latter with the lingual artery, a well individualized anterior prolongation originates from this face , about 20 millimeters in length, which is directed forward, placing itself between the myoglossus and mylohyoid muscles, and comes into contact with the sub-lingual gland.

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

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

Extremities

Forelimb: It is rounded in appearance and is applied to the anterior belly of the digastric and the mylohyoid. Posterior limb: It is 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.

Edges

Upper edge: Corresponds to the mylohyoid in front, to the mucosa of the alveolo-lingual sulcus behind, between the mucosa and the gland the lingual nerve penetrates into the region, with the submandibular ganglion remaining below the nerve.

Lateral edge: it is located at the level of the lower edge of the jaw.

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

Driver excreta

The excrete conductors (Wharton), having a length of 4 to 5 centimeters and a thickness of 3 to 4 millimeters, is a whitish-walled, thin-walled conduit. It emerges on the deep side of the gland through the union of two collectors and goes forward and inward, crosses over the mylohyoid and inside the sublingual gland until reaching the sublingual curuncle, located at the base of the lingual frenulum, where it opens in the oral cavity by the umbilical ostium (bordeu). An important relationship in its path is the lingual nerve located above the duct and from the back to the front crossing it 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 highly variable and are linked by fibrovascular pedicles, each gland consists of 10 lobules.

Vessels: The arterial branches directly and indirectly come from the facial one through their submental clays, ascending palates. From the facial originates the main artery that reaches through its deep face, the veins empty into the facial and submental.

Lymphatic: The lymphatic drainage is done towards the submandibular lintonodules .

Nerves: Nerves intended gland type parasympathetic will arrive in the rope the tympanum to the submandibular ganglion and sympathetic nerve fibers by flexos located in the adventitia of the arteries.

Sublingual gland

It is the most anterior of the major salivary glands, located in the floor of the mouth, inside the jaw and on each side of the chin , 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 from 25 to 30 millimeters, its height from 10 to 12 millimeters and its thickness from 6 to 8 millimeters, it is described as two superficial and deep faces; two edges: upper and lower and two extremities posterior and anterior.

Relations

The gland, unlike the parotid and submandibular glands, is not found 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 aspect: it is related to the genioglossal and inferior longitudinal lingual muscles , and between them and the gland is the lingual nerve and the exmandor duct of the submandibular.

Edges

Bottom edge: corresponds to the groove formed by separating the mylohyoid and genioglossus muscles.

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

Posterior end: it is related to the prolongation anterior to the submandibular.

Anterior end: the muscles that originate in it are related to the mentodian spine: genioglossus and geniohyoid.

Anatomical constitution

It is a mixed gland with serous, mucous, and mixed acini, with mucous predominance.

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

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

Lymphatic: it flows into the submandibular lymph nodes.

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

 

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