Topography of the parotid gland. Projection of the excretory duct of the parotid salivary gland. A) Borders of the parotid-chewing region of the face

On fig. 1 to the right of the text shows a small part of the parotid gland (OC), a fragment of which is enlarged in fig. 2.

Parotid salivary gland surrounded by a connective tissue capsule (K), from which septa extend (P). The septa and capsule form the stroma of the organ. Septa divide the parenchyma into lobules (D). One of them is specially isolated from the stroma to make its polygonal shape visible.

Each lobule consists of spherical or pear-shaped structural and functional units - acini (A), which secrete their serous secretion into intercalary ducts (VP) of the parotid gland where it comes from striated ducts (IP). Interlobular ducts (MP) leave the lobules and go inside the connective tissue septa along with muscular arteries (A), veins (B), nerve fibers (NV) and lymphatic vessels (LS).

Finally, the interlobular ducts reach a branch of the main excretory duct (EP) through which the aqueous parotid secretion reaches the oral cavity. A dense capillary network (CAP) surrounds the acinus. It is also common to see fat cells (FA) among the acini.

In Figure 1, to the left of the text, the acini of the parotid gland are visible. Acini, intercalary and striated ducts are isolated from the parenchyma of the gland and cut in different directions for better understanding of their structure. Diverse cells form the three structures shown in Fig. 2-4.

Acini (A) are round, pear-shaped or mulberry-like secretory glandular complexes composed of densely associated granular serous cells (SCs) that form a single-layered cuboidal or prismatic epithelium lying on a basement membrane (BM).

The acini are surrounded by spindle-shaped and/or stellate myoepithelial cells (MCs), which are located between the secretory cells and their basement membrane. The contraction of myoepithelial cells accelerates the secretion of saliva.

The acini open into the intercalary ducts (IP). These are tubules with a diameter of about 20 microns, the wall of which is formed by a single layer of squamous or cubic epithelium. The length of the intercalary ducts in the parotid gland is significant; several intercalary ducts can unite and form a single canal, which then flows into the striated duct.

Striated ducts (PI) of the parotid gland formed by high prismatic cells, penta- and hexagonal in shape, the bases of which are visible if the basement membrane (BM) is separated. The apical poles of the cells protrude into the lumen of the duct. The basal part of the cells is occupied by basal striation (BI).

Abundantly branching capillary network (Cap) surrounds the acini and the entire system of excretory ducts. Among the acini, there is a markedly variable number of white fat cells (FA). All fat cells have their own basement membrane.

Rice. 2. Serous cells have a central spherical nucleus and basophilic cytoplasm. This basophilia is associated with ergastoplasm (E), which, together with the developed Golgi complex (G), is responsible for the synthesis of secretory granules (SG). Serous cells and cells of the walls of the excretory system of the gland are connected to each other by junctional complexes (SCs).

Rice. 3. The cells of the intercalated ducts have a central nucleus, as well as underdeveloped organelles and form deep interdigitations in the region of the basal sections with many processes (O) of neighboring cells.
A small number of secretory granules containing mucus are located in the cytoplasm of the apical pole of the cell. The basement membrane (BM) surrounding the acini continues into the basement membrane of the intercalary ducts and the entire system of excretory ducts.

Rice. 4. The cells of the striated ducts have an elliptical nucleus and well-developed organelles. Under an electron microscope, the basal striation is a highly developed basal labyrinth (BL), consisting of deep and branched invaginations of the cell membrane. Numerous infranuclear cytoplasmic compartments containing one to several rod-shaped mitochondria (M) give the cells their basal striation. The basal labyrinth is involved in water transport and sodium reabsorption from saliva. The lateral prismatic processes (O) interdigitate with the processes of adjacent cells. The apical poles of the cells are reinforced with well-developed junctional complexes (SCs).

Osmiophilic secretory granules (SG) containing the vasoconstrictor peptide kallikrein originate from the Golgi complex. The striated ducts are also excretory and at the same time secretory ducts.

parotid gland,glandula parotidea, is a serous gland. This is the largest of the salivary glands, has an irregular shape.

Topography of the parotid salivary gland

It is located under the skin anteriorly and downward from the auricle, on the lateral surface of the mandibular branch and the posterior edge of the masseter muscle.

The fascia of this muscle is fused with the capsule of the parotid salivary gland.

At the top, the gland almost reaches the zygomatic arch, below - to the angle of the lower jaw, and behind - to the mastoid process of the temporal bone and the anterior edge of the sternocleidomastoid muscle.

In depth, behind the lower jaw (in the maxillary fossa), the parotid gland with its deep part, pars profunda, adjacent to the styloid process and the muscles starting from it: stylohyoid, stylohyoid, stylopharyngeal.

The external carotid artery, submandibular vein, facial and ear-temporal nerves pass through the gland, and deep parotid lymph nodes are located in its thickness.

Structure parotid salivary gland

The parotid gland has a soft texture, well-defined lobulation. Outside, the gland is covered with a connective capsule, the bundles of fibers of which go inside the organ and separate the lobules from each other.

ducts parotid salivary gland

excretory parotid duct, ductus parotideus(stenon duct), exits the gland at its anterior edge, goes forward 1-2 cm below the zygomatic arch along the outer surface of the masticatory muscle, then, rounding the anterior edge of this muscle, pierces the buccal muscle and opens on the eve of the mouth at the level of the second upper large root tooth.

In its structure, the parotid gland is a complex alveolar gland. On the surface of the chewing muscle next to the parotid duct is often located accessory parotid gland,glandula parotis accessoria.

Vessels and nerves of the parotid gland

Arterial blood enters through the branches of the parotid gland from the superficial temporal artery. Venous blood flows into the mandibular vein. The lymphatic vessels of the gland flow into the superficial and deep parotid lymph nodes. Innervation: sensitive - from the ear-temporal nerve, parasympathetic - postganglionic fibers in the ear-temporal nerve from the ear node, sympathetic - from the plexus around the external carotid artery and its branches.

The parotid gland (glandula parotis) is a large salivary gland of irregular shape (Fig. 54, 55). On a cross section it resembles a triangle, with its deep part it enters the retromaxillary fossa, bounded in front by the branch of the lower jaw, from above by the auditory canal and temporomandibular joint, from behind by the mastoid process with the sternocleidomastoid muscle and from below by the fascial septum separating the parotid gland from the submandibular . With its front edge, the organ enters the outer surface of the masticatory muscle.

Rice. 54. Topography of the parotid-masticatory region.
1-r. temporalis n. facialis; 2-a. temporalis superficialis; 3 - n. auriculotemporalis; 4-a. transversa faciei; 5 - glandula parotis; 5 - m. sternocleidomastoideus; 7-r. colli n. facialis; 8-r. marginalis mandibulae n. facialis; 9-a. facialis; 10-v. facialis; 11 - mm. buccales n. facialis; 12 - ductus parotideus; 13-r. zygomaticus n. facialis; 14 - m. masseter.

Rice. 55. Frontal section of the auditory canal and parotid salivary gland. 1 - tympanic membrane: 2 - styloid process with muscles attached to it; 3 - capsule of the parotid gland; 4 - parotid gland; 5 - santorini cracks; 6 - cartilage of the ear canal; 7 - temporal muscle.

The fascia of the region creates a case for the parotid gland, enveloping it from all sides. From the outside, the fascia is thickened and is described as an aponeurosis. The fascia is thinned in the area where it adheres to the peripharyngeal tissue and the cartilaginous part of the auditory canal, which has santorini fissures. As a result, pus from the fascial bed of the gland is able to break into the peripharyngeal space and into the auditory canal, the latter is more often observed in children. In addition to the fascial cover, the parotid gland is shrouded in a thin capsule, which, together with the fascia inside the organ, gives rise to spurs, dividing it into lobules. This prevents the spread of the purulent process in the gland itself. The size of the parotid gland is different. Sometimes it only slightly overlaps the back of the masticatory muscle, but in some cases it almost reaches its anterior edge, especially when additional lobules of the gland are observed along the stenon duct.

The excretory duct of the parotid gland (ductus parotideus) is formed from the collecting stems still within the organ. Sometimes these stems form a common duct outside the gland. The duct may not be single. The length of the duct is from 1.5 to 5 cm, the diameter of the lumen is 2-3 mm. The duct, having passed to the anterior edge of the masticatory muscle, goes into the fatty lump of the cheek, pierces the buccal muscle, goes for 5-6 mm under the mucous membrane and opens on the eve of the oral cavity. The projection of the duct on the skin follows from the tragus of the auricle to the corner of the mouth or is located on a parallel next to the transverse finger below the zygomatic arch. In the direction of the duct and slightly above it, the transverse artery of the face passes.

The internal part of the parotid gland, located behind the branch of the lower jaw (Fig. 56), is pierced by the external carotid artery, where it divides into terminal branches: the jaw, posterior auricular and superficial temporal. Outside the carotid artery is the external jugular vein. Within the gland, the transverse facial and posterior ear veins join the vein.

Rice. 56. Parotid-chewing area and peripharyngeal space (horizontal cut).
1 - fatty lump of the cheek; 2 - m. buccinator; 3 - upper jaw; 4 - Ch. pterygoideus medialis; 5 - pharynx; 6 - styloid process with muscles attached to it; 7-a. carotis interna with n. vagus, n. accessorius, n. hypoglossus; 8 - I and II cervical vertebrae; 9 - ganglion cervicalis superior trunci sympathici; 10-v. jugularis interna n. glossopharyngeus; 11 - parotid salivary gland; 12 - outer sheet of the own fascia of the face; 13 - lower jaw: 14 - m. masseter. The arrow leads to the peripharyngeal space.

Within the parotid gland are superficial and deep lymph nodes. The former collect lymph from the skin of the face, auricle, external auditory canal and tympanic cavity; the second - from the soft palate, the posterior half of the nasal cavity. Lymph flows into the nodes under the sternocleidomastoid muscle, at the internal jugular vein. Inflammation of the deep lymph nodes located in the thickness of the gland creates a clinical picture of mumps (pseudoparotitis).

The facial nerve passes through the thickness of the parotid gland, innervating the mimic muscles. The nerve, leaving the stylomastoid foramen, goes down a little and, turning sharply up, following under the earlobe, enters the thickness of the parotid gland. In the thickness of the gland, it forms a plexus, and outside it forms a large crow's foot (pes anserinus major) (Fig. 57). The position of the main branches of the nerve is relatively constant. The starting point for the projection of the branches is the root of the earlobe.

Rice. 57. Topography of the branches of the facial nerve.
1 - n. facialis; 2 - m. temporalis; 3-r. zygomatici; 4-r. buccalis; 5-r. marginalis mandibulae; 6-r. colli; 7-n. auricularis posterior; 3 - plexus parotideus.

Temporal branches (rami temporales) are directed to the upper edge of the orbit; innervates the frontal muscle and the circular muscle of the orbit. The zygomatic branches (rami zygomatici) follow the zygomatic bone and further to the orbital zone; innervates the zygomatic muscle and the circular muscle of the orbit. The buccal branches (rami buccales) go to the mouth area; innervate the muscles of the mouth. The marginal branch of the jaw (ramus marginalis mandibulae) runs along the edge of the lower jaw; innervates the muscles of the lower lip. The cervical branch (ramus colli) follows behind the angle of the lower jaw and goes to the neck to m. platysma. The listed branches of the facial nerve are more often represented on the face by two or three stems. O. S. Semenova singles out the construction of a nerve with multiple connections and with an isolated course of nerve trunks. Taking into account the position of the branches of the facial nerve, it is recommended to make incisions on the face according to the principle of diverging rays with the earlobe as a starting point and taking into account the position of the main nerve trunks.

The front section of the region is occupied by m. masseter. Under the masticatory muscle there is a layer of loose fiber, where purulent processes can develop, more often of odontogenic origin (Fig. 58).

Rice. 58. Topography of the space under the masticatory muscle.
1 - m. masseter; 2 - n. massetericus and a. masseterica; 3 - a. and v. temporalis superficialis; 4 - n. auriculotemporalis; 5 - glandula parotis; 6 - m. sternocleidomastoideus; 7-a. facialis; 8-v. facialis; 9-a. buccinatoria with m. buccinator; 10 - ductus parotideus.

Directly in front of this muscle, through the lower edge of the lower jaw, a. facialis et v. facialis. Both vessels above the edge of the jaw deviate towards the angle of the oral fissure. The superficial position of the artery on the bone allows palpation at the edge of the jaw and masticatory muscle to feel its pulse shocks.

23.1. ANATOMY AND PHYSIOLOGY OF THE LARGE SALIVARY GLANDS

Salivary glands - This is a group of secretory organs of various sizes, structures and locations that produce saliva. There are small and large salivary glands. Minor (small) salivary glands are located in the mucous membrane of the oral cavity, according to their location they are distinguished: labial, buccal, palatine, lingual, gingival, and also these glands are located in the mucous membrane of the nasopharynx and tonsils. To major salivary glands relate parotid, submandibular and sublingual glands.

Rice. 23.1.1. Parotid gland (according to V.P. Vorobyov, 1936).

The skin, subcutaneous muscle of the neck, parotid-masticatory fascia, nerves and partially vessels were removed.

I - zygomatic muscle; 2 - circular muscle of the eye; 3- excretory duct of the parotid gland; 4- additional lobules of the gland; 5- chewing muscle; 6 - parotid gland; 7- superficial temporal artery; 8 - superficial temporal vein; 9- sternocleidomastoid muscle;

10 - external carotid artery;

II - external jugular vein; 12 - hyoid bone; 13 - submandibular gland; 14 - digastric muscle; 15 - facial vein; 16 - facial artery; 17 - triangular muscle of the mouth; 18 - buccal muscle.

parotid gland(glandula parotis) - a paired alveolar serous salivary gland located in the parotid-masticatory region. It is the largest of all salivary glands. It is located in the retromaxillary fossa and protrudes slightly beyond its limits (Fig. 23.1.1). The boundaries of the gland are: above- zygomatic arch and external auditory meatus; behind- mastoid process of the temporal bone and sternocleidomastoid muscle; ahead- covers the posterior segment of the masticatory muscle itself; downward- falls slightly below the angle of the lower jaw; from the medial side- the styloid process of the temporal bone with muscles starting from it and the wall of the pharynx. The parotid gland is divided into two lobes: superficial and deep. The average weight of the gland is 20-30 g. In the unchanged state, the gland is poorly palpable under the skin, because surrounded on the outside by a dense and continuous connective tissue capsule, and on the medial side, the capsule is thinner and discontinuous (in this way, the parotid gland communicates with the peripharyngeal space). In places where the capsule is expressed, it is firmly fused with the muscles and fascia. Numerous processes go from the capsule of the gland into its thickness, which form the stroma of the gland and divide it into separate, but firmly connected into the total mass of lobules. The small salivary ducts of the lobules merge into larger ones (interlobular), and then gradually merge into ever larger ducts and, ultimately, unite into the excretory duct of the parotid gland. An additional duct flows into this duct at the anterior edge of the masticatory muscle from the additional lobe of the parotid gland, which is located above. An additional proportion is found in 60% of patients.

Rice. 23.1.2. Morphological structure of the parotid gland: a) in a child; b) in adolescence; c) in middle age; d) old age (there is fatty degeneration and sclerosis of the parenchyma).

The external carotid artery passes through the thickness of the gland (gives off its branches - a. temporalis superficialis and a. maxillahs), veins - v. parotideae anteriores and posterhores, which merge into v. facialis, facial nerve, ear-temporal nerve, as well as sympathetic and parasympathetic nerve fibers. Around the parotid gland and in its thickness are the lymph nodes (section 9.2, volume I of this Guide).

The length of the extraglandular part of the excretory duct usually does not exceed 5-7 cm, the diameter (width) is 2-3 mm. In older people it is wider than in children. Usually the excretory duct departs at the border of the upper and middle thirds of the gland. The transition of the intraglandular part of the duct to the extraglandular part is located quite deep in the gland. Therefore, a part of the parotid gland is located above the extraglandular part of the excretory duct. The direction of the excretory duct may vary, i.e. it is straight, arched, curving, and very rarely forked. The excretory duct of the parotid gland runs along the outer surface m. masseter, leans over her front to
Paradise and passing through the fatty tissue of the cheek and the buccal muscle opens on the mucous membrane of the cheek in the vestibule of the mouth (opposite the second upper molar).

Rice. 23.1.3. The structure of the parenchyma of the gland with the presence of an intraglandular lymph node. Microphotogram of parotid tissue. Hematoxylin-eosin staining.

Macroscopically, the parotid gland, depending on the blood supply, has a pinkish or yellowish-gray color, a bumpy surface and a moderately dense texture. In older people, the glands are paler, heavy, of uneven density.

The main structural units of the parenchyma of the parotid gland are the alveolar terminal secretory sections (acini), compactly located in the lobules and consisting of cells of the glandular epithelium, with small ducts located between them. The terminal secretory sections are represented by pyramidal cylindrical cells, with a wide base adjacent to the basement membrane (Fig. 23.1.2 - 23.1.3). Near the orifice are mucus-secreting goblet cells that form a chemical barrier to microbes ascending through the ducts into the gland. With age, the zones of interlobular connective tissue increase, areas of fatty degeneration of the parenchyma appear with a decrease in the mass of the terminal secretory sections and atrophy of the glandular tissue.

A large experimental material gives grounds for the assertion that the parenchyma of the salivary glands produces biologically active substances such as hormones: parotin - nerve and epithelial growth factor, thymocin- transforming factor and others (Fleming H.S., 1960; Suzuki J. et al., 1975; Rybakova M.G., 1982, etc.).

In practically healthy people, within one hour, the parotid gland produces from 1 to 15 ml of unstimulated saliva (about 5 ml on average). Normally, the pH of saliva of the parotid gland ranges from 5.6 to 7.6 (Andreeva T.B., 1965). According to the composition of the secret, the parotid gland belongs to purely serous glands.

submandibular gland (glandula submandibularis) - a paired alveolar, in some places tubular - alveolar salivary gland, which is located in the submandibular triangle of the neck (Fig. 23.1.4).

It is located between the base of the lower jaw and both abdomens of the digastric muscle. Its upper-lateral part of the gland is adjacent to the fossa of the same name (fossa of the submandibular gland) of the lower jaw, from behind reaching its angle, approaching the posterior abdomen m. digastricus, to the stylohyoid, to the sternocleidomastoid and medial pterygoid muscles, and in front it comes into contact with the hyoid-lingual and with the anterior belly of the digastric muscle. For a considerable length of its front part, the iron is covered m. mylohyoideus, and behind it bends over its rear edge and comes into contact with the sublingual gland. Near the angle of the mandible, the submandibular gland is located close to the parotid gland.

Rice. 23.1.4. Submandibular and sublingual glands, inside view (according to V.P. Vorobyov,

Median incision of the floor of the mouth and lower jaw; the mucous membrane is removed; ducts of glands are allocated.

1- medial pterygoid muscle; 2- lingual nerve; 3- small sublingual ducts; 4 - the mouth of the excretory duct of the submandibular gland; 5- large sublingual duct; 6- body of the lower jaw; 7- sublingual gland; 8 - excretory duct of the submandibular gland; 9- jaw - hyoid muscle; 10 - submandibular gland.

Thus, the bed of the submandibular gland is limited: from within the diaphragm of the floor of the mouth and the hyoid-lingual muscle; outside- the inner surface of the body of the lower jaw; from below- anterior and posterior belly of the digastric muscle and its intermediate tendon.

The excretory duct of the submandibular gland departs, as a rule, from its upper medial section. Bending over the posterior edge of the maxillo-hyoid muscle, it is located on the lateral side of the hyoid-lingual muscle, and then passes between it and the maxillo-hyoid muscle. Next comes between the sublingual gland and the more medially located chin-lingual muscle. The excretory duct opens on the mucous membrane of the bottom of the mouth on the side of the frenulum of the tongue. At the site of the outlet of the duct, the mucous membrane forms an elevation, which is called sublingual meat (caruncula sublingualis). The length of the excretory duct of the submandibular gland does not exceed 5-7 cm, and the width (diameter) of the lumen is 2-4 mm (A.V. Klementov, 1960). The mouth of the excretory duct is much narrower than in the parotid gland (PA. Zedgenidze, 1953; L. Sazama, 1971).

The capsule of the gland is formed by splitting the surface sheet of the own fascia of the neck. The capsule is thick on the outside and thin on the inside. Loose fatty tissue is located between the capsule and the gland, which makes it easy to peel the gland (in the absence of inflammatory changes) from the surrounding soft tissues. Lymph nodes are located in the fascial bed of the gland (Section 9.2, Volume I of this Guide). The weight of the gland averages from 8 to 10 g, and after the age of 50, the weight of the gland decreases (A.K. Arutyunov, 1956). The consistency of the gland is of moderate density, the color is pinkish-yellow or gray-yellow.

The submandibular gland is supplied with blood by the facial, lingual, and submental arteries. The facial artery enters the posterior submandibular triangle (departs from the external carotid artery). It is covered by the posterior belly of the digastric muscle and the awl by the hyoid muscle. In this place, it goes obliquely up and forward, often located under the gland. Less often - passes behind the gland, very rarely lies on the gland. Along the edge of the lower jaw, along the outer surface of the gland, the submental artery departs from the facial artery, which gives off small branches to the gland. In the posterior part of the lower outer surface of the gland, between it and the aponeurosis, there is a facial vein.

lingual nerve, leaving the gap between the pterygoid muscles, lies directly under the mucous membrane of the bottom of the mouth and passes between it and the posterior pole of the submandibular gland. The position of the lingual nerve must be taken into account when performing surgical interventions on the excretory duct of the gland. hypoglossal nerve enters the submandibular triangle between the posterior belly of the digastric muscle and the outer surface of the hyoid-lingual muscle. Being on the muscle, the nerve descends, forming an arc, convex downwards and covered by the gland. In chronic inflammatory processes in the submandibular gland, the nerve may be in adhesions and damage may occur during the extirpation of the gland.

facial nerve, or rather its marginal branch, runs about 1 cm below the lower edge of the lower jaw. Therefore, the incision in the submandibular region is made 1.5-2 cm below the lower edge of the jaw. The secretory fibers of iron are received from the vegetative submandibular node (ganglion).

In healthy people, from 1 to 22 ml of unstimulated saliva is produced within an hour (on average, about 12 ml). In the saliva of the submandibular gland, pH ranges from 6.9 to 7.8 (T.B. Andreeva, 1965).

By the nature of the secret, the submandibular gland is mixed, i.e. seromucosal.

The epithelium of the ducts is the same as in the parotid gland, with the only difference being that it is often multi-layered (P. Rother, 1963). This may explain the significant resistance to the pressure of the contrast (in sialography) or washing fluid (in the treatment of inflammatory diseases of the gland).

sublingual gland{ g. sublingualis) - steam tubular - alveolar salivary gland located at the bottom of the oral cavity. The sublingual gland is located in the cellular space of the floor of the mouth between the frenulum of the tongue and the projection of the wisdom tooth. Outside the gland is adjacent to the inner surface of the body of the lower jaw (to the recess for the sublingual gland). From within borders on the hyoid-lingual and genio-lingual muscles (the lingual nerve, the terminal branches of the hyoid nerve, the lingual artery and vein, the excretory duct of the submandibular gland adjoin it). Bottom- located in the gap between the maxillo-hyoid and chin-hyoid muscles. Above- mucous membrane of the bottom of the mouth. The gland is surrounded by a thin capsule, from which septa extend, dividing the gland into lobules (Fig. 23.1.4).

The weight of the gland is on average from 3 to 5 g. Its dimensions vary (the length is on average from 1.5 to 3 cm). The color of the gland is gray - pink. The gland has a lobular appearance, especially in the posterolateral sections, and its separate ducts, which are called small sublingual ducts. The latter open along the sublingual fold at the bottom of the mouth. The main mass of the gland is collected in one common duct, which flows into the excretory duct of the submandibular gland near its mouth. The common excretory duct is 1 to 2 cm long and 1 to 2 mm in diameter. Rarely, the sublingual duct can open on its own near the orifice of the submandibular duct. The gland is supplied with blood by the hyoid artery (departs from the lingual artery), venous outflow is carried out through the hyoid vein. It receives sympathetic innervation from the autonomic hyoid ganglion. Innervation - from the lingual nerve.

According to the composition of the secret, the sublingual gland refers to mixed serous-mucous glands.

In an adult, saliva secretion is about 1000-1500 ml per day, and a lot depends on how this secretion is stimulated by food and other external and internal impulses (L. Sazama, 1971).

According to the studies of W. Pigman (1957), 69% of saliva is secreted from the major salivary glands by the submandibular glands, 26% by the parotid and 5% by the sublingual glands.

The secretion of the small salivary glands is assessed using filter paper of a certain mass, which is weighed after the study (V.I. Yakovleva, 1980). The average number of secreted small salivary glands is determined in the area of ​​the mucous membrane equal to 4 cm 2 . Indicators that are normal in apparently healthy people are presented in Table 9.1.2 (Volume I of this Guide).

Saliva contains lysozyme (see Table 9.1.1, Volume I of this Guide), amylase, phosphatases, proteins, sodium, potassium, calcium, phosphorus, magnesium ions, parotin and other chemicals, endocrine factors, enzymes.

In conclusion, I want to remind you that the names of the ducts of the large salivary glands are also associated with the names of scientists. So the duct of the parotid gland is commonly called stenon(Stenonii), submandibular - Wharton(Wartonii), the main duct of the sublingual gland - bartalin(Bartalinii), and the small ducts of the sublingual gland - rivinium(Rivini).

Regio parotideomasseterica

In the subcutaneous tissue of the region, there are skin arteries, the subcutaneous venous network, branches of the large ear and ear-temporal nerves, the transverse artery of the face and branches of the facial nerve emerging from the bed of the parotid gland in the upper and in front of the glandula parotis.

Rice. 74. Differences in the structure of the parotid salivary gland and the parotid duct.
a - trapezoidal parotid gland and straight parotid duct; b - semilunar parotid gland and arcuate duct; c - triangular parotid gland and geniculate duct; d - oval parotid gland and descending parotid duct.

Rice. 75. Projections of the parotid, submandibular and sublingual salivary glands and their ducts.

1 - parotid gland; 2 - parotid duct; 3 - parotid papilla; 4 - submandibular gland; 5 - submandibular duct; c - sublingual gland; 7 - sublingual duct.

Deeper than the subcutaneous tissue and superficial fascia are fascia parotidea and fascia masseterica, covering the parotid gland and masticatory muscle and connecting to each other at the points of contact.

Rice. 76. Retromaxillary fossa. Bony openings that pass blood vessels and nerves to the face. Interaponeurotic cellular space of the temporal region. View from the right, side and somewhat in front (2/3).
The parotid gland is removed; uncovered interaponeurotic cellular space of the temporal region.

chewing muscle occupies the anterior part of the region and consists of two bundles with oblique and vertical fibers. A. masseterica and n. massetericus enter the chewing muscle from the inside, and the nerve inside the muscle goes obliquely forward and down. Inward from the masticatory muscle is a branch of the lower jaw. The posterior upper part of the branch (processus condylaris), not covered by the masticatory muscle, is involved in the formation of articulatio tempo-romandibularis. The articular surfaces of the temporomandibular joint of the caput mandibulae and fossa mandibularis, together with the tuberculum articulare of the temporal bone, are lined with fibrous cartilage. Between the articular surfaces is a biconcave fibrocartilage discus articularis, which divides the joint cavity into two floors. The articular bag is attached to the edges of the cartilage of the articular surfaces and discus articularis. Outside, the joint strengthens the lig. laterale.

The posterior part of the region, as well as the posterior maxillary fossa, is occupied by the parotid gland, which is adjacent: in front - to the posterior and outer surface of the masticatory muscle, to the branch of the lower jaw, medial pterygoid muscle, lig. sphenomandibulare, and in the lower part - to the submandibular salivary gland; behind - to the sternocleidomastoid muscle, the posterior belly of the digastric muscle and the mastoid process; medially - to the styloid process with muscles extending from it (mm. stylohyoideus, styloglossus and stylopharyngeus), to the internal jugular vein and the internal carotid artery lying more medially with nerves located near them and to the tissue of the anterior parapharyngeal space; laterally - to subcutaneous fat; from above - to the external auditory canal; from below - to a thickened sheet of the second fascia, extending from the sheath of the sternocleidomastoid muscle to the angle of the lower jaw and separating the parotid gland from the submandibular gland. It should be borne in mind that the parotid gland does not directly adjoin the above elements. Between the gland and them lies the fascia parotidea, which forms a bed for the gland, surrounding it on all sides, with the exception of its pharyngeal process (pars profunda). The entire gland is permeated with connective tissue stroma, which is a direct continuation of the parotid fascia and firmly connects the gland with its capsule. Outside, the parotid fascia is connected to the fascia of the muscles that limit the parotid gland, and is also attached to the edge of the lower jaw, zygomatic arch, mastoid and styloid processes.

The glandula parotis itself in its external outlines can be lunate, triangular, oval and trapezoid.

Excretory duct parotid salivary gland(ductus parotideus), having a diameter of 3-5 mm, comes out of the gland, most often in its upper third, and, having rounded the anterior edge of the chewing muscle and passing through the cheek muscle, opens into the vestibule of the oral cavity in most cases at the level of the first or second upper molars.

Due to the variability in the location of the duct, its projection on the cheek is best determined by the limits of the triangle, the sides of which are the following lines: the first - from the lower edge of the upper medial incisor to the upper edge of the external auditory canal; the second - from the front of the nose to the top of the mastoid process; the third - perpendicular to the zygomatic arch, restored from the angle of the lower jaw.

The external carotid artery enters the bed of the gland through the inferomedial surface of the fascia parotidea, with which the sheath of the artery is firmly connected; through the parenchyma of the medial part of the gland, the artery goes up and laterally to the posterior edge of the upper middle quarter of the lower jaw branch, where it divides into its terminal branches - a. maxillaris and a. temporalis superficialis.

Lateral to the external carotid artery is the retromandibular vein (v. retromandibularis), formed from the confluence of vv. temporalis superficialis, temporalis media, transversa faciei, maxillaris and veins from the parotid gland and masticatory muscle.

Rice. 77. Blood supply and innervation of the teeth of the upper and lower jaws. Subaponeurotic cellular space of the temporal region. View from the right, side and somewhat in front (2/3).
The temporal fascia was removed and the temporalis muscle and the posterior process of the fatty body of the cheek, located outside the muscle, were exposed; the canal of the lower jaw and the tubules of the upper jaw were opened, passing vessels and nerves to the teeth.

The facial nerve, leaving the foramen stylomastoideum, pierces the parotid fascia and enters the parotid bed directly at the base of the styloid process, where it divides into branches that form the plexus parotideus in the thickness of the gland. Diverging fan-shaped forward and outward, the branches of the plexus pass behind and then laterally from the external carotid artery and inside and outside of the retromaxillary vein. Having reached the outer surface of the gland, the branches of the nerve in the form of numerous rr. temporales, zygomatici, buccales, marginalis mandibulae and colli pass through the fascia parotidea and in the subcutaneous tissue are sent to the corresponding areas where they innervate the mimic muscles. R. colli innervates the subcutaneous muscle of the neck.

Rice. 78. Temporomandibular joint; right (1.1/1).
a (side view) - the ligaments of the joint are removed, the lower jaw is pulled down and forward, as a result of which you can see the upper and lower floors of the joint; b (top view) - the articular head of the lower jaw and the articular disc connected to it and tilted back; on the anterior periphery of the articular head and disc, the attachment of the lateral pterygoid muscle is visible; c (bottom view) - mandibular fossa of the temporal bone, covered with cartilage.

Another nerve passing through the bed of the gland - n. auriculotemporalis - departs from the back of the third branch of the trigeminal nerve, covers the middle meningeal artery and above a. maxillaris from under the articular process of the lower jaw penetrates into the bed of the gland, where it is located medially to the superficial temporal artery. Here, the nerve gives off a number of branches to the parotid gland, the external auditory canal, the tympanic membrane, and to the facial nerve.

Rice. 79. Temporal pterygoid cellular space of the deep region of the face. The maxillary cavity and the relation to it of the roots of the teeth of the upper jaw. View from the right, side and somewhat in front (2/3).
The lower part of the temporalis muscle, the anterior and middle parts of the lower jaw branch were removed, and the temporal pterygoid cellular space was opened. The anterior wall of the maxillary sinus was trepanned and the ratio of the sinus floor to the roots of the teeth of the upper jaw was shown.

Under the fascia parotidea, on the surface of the gland and in depth along the external carotid artery and the retromaxillary vein, there are nodi lymphatici parotidei superficiales and profundi.

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