1.Serrous acinus serous acinus

2. Mucous acinus mucous acinus

3. Mixed acinus mixed acinus

3. Myoepithelial cell

The tiniest terminal branch of the catheter, connecting the acinus to the secretory tube. Mucous cells are numerous—the leap tube is shorter (sublingual gland) Less mucus cells - longer leap tubes (paratum gland)

Light microscope: A monolayer tube surrounded by 4 to 6 cubic cells, often located between crowded cells, with fewer cytoplasm and lighter staining; the nucleus is round and large, located in the center of the cell

Electron microscopy: There is a small amount of rough endoplasmic reticulum in the basal cytoplasm, and there is a Golgi complex in the top cytoplasm. Occasionally, secretory granules are found. Microvilli at the top of the cell protrude into the gland cavity. Myoepithelial cells can be seen around the duct cells. Interlude tube cells can be regarded as stem cells, which can be differentiated into acinar cells, myoepithelial cells and secretory tube epithelial cells when needed.

Continuous with the leap tube, with a thicker diameter, and the wall of the tube is composed of monolayer columnar cells Myoepithelial cells can also be seen near the leap tube

Light microscope: Cytoplasm is abundant and strong basophilic; nuclear circle is located in the center of the cell; longitudinal streaks arranged perpendicular to the basement membrane can be seen in the cytoplasm near the basement - the streaks

Electron microscopy: The cell membrane near the substrate repeatedly rewinds into the cells, forming parallel arrangements of wrinkles perpendicular to the substrate. The inner cysts of the wrinkled inner cysts contain a large number of vertically arranged mitochondria-longitudinal streaks

Function: The secretory tube has the function of transporting electrolytes and water. When the acinar secretion flows, it maintains sodium and discharges potassium, transports water, and isotonic becomes hypotonic, similar to the distal renal convex tubules.

Also known as a collection tube, it starts in the lobular and then enters the connective tissue between the lobular, called the interlobular catheter

Light microscope: The tube wall cells become columnar, the cytoplasm is diluted, the tube diameter becomes thicker, and the wall cells gradually become pseudo-complex, and become a complex squamous epidermis again. The excretion tube is also involved in the ion transport of saliva and the process of isotonic to hypotonic

Anatomical features: The largest gland, with a connective tissue capsule on the outer layer, located in the outer auditory canal, anterior to the mastoid process, under the zygomatic arch, lateral posterior to the mandibular ascendant branch, and surface of the masseter muscle. Superficial lobes-front to the external ear; deep lobes- posterior concave of the mandibular catheter open to the buccal mucosa against the second maxillary molar

Histological characteristics: 1. Pure serous glands (a small amount of mucous cells can be seen in newborns) 2. The leap tube is long and has branches; there are many secretory tubes. 3. The glands are often accompanied by lymphatic tissue (glands are visible in the surrounding lymphatic); it may be related to the development of the salivary glands around the jugular vein lymphatic sac. This is also the histological basis for the salivary glands to develop benign lymphoepithelial lesions, gland lymphomas and malignant lymphomas.

Anatomical features: There is a clear mask outside Most: Inside the submandibular triangle; A small part: above the free edge of the mandibular hyoid muscle The catheter opens to the meat pubic side of the tongue lace

Histological characteristics: Mixed glands, mainly serous acinars The leap tube is shorter; the secretion tube is longer Diffusion of lymphoid tissue is often found around the catheter

Anatomical features: 1. No clear connective tissue membrane 2. Located between the oral base mucosa and mandibular hyoid muscle 3. Main duct—submandibular duct, small duct—sublingual duct, submandibular duct, sublingual duct, sublingual duct

Histological characteristics: Mixed gonads, mainly mucous acinars. The leap tube and secretory tube are dysplasia, and the acinars can be directly connected to the excretion tube.

Mainly produces and secretes saliva Quantity: 1000~1500ml/day Ingredients: Water (99%) Inorganic ions—sodium, potassium, calcium, bicarbonate Organics—glycoprotein, amylase, peroxidase, lysozyme, globulin, etc.

1. Digestive function (1) Emulsify and dissolve food. (2) Direct digestion: amylase digests starch; fat-soluble enzymes play a synergistic role in the intragastric decomposition of triglycerides. (3) Maintain taste function: taste vegetarian

2. Lubrication, defense and protection functions (1) Lubrication effect: mucopolysaccharide (2) Formation of protective barriers (3) Soft tissue repair: epithelial growth factor (4) Irrigation effect (5) Buffering effect: (6) Proteins that bind calcium to form a saliva film, which can directly exchange ion with teeth. (7) Lipoprotein thrombocytosis, etc. shorten the coagulation time.

3. Antibacterial function (1) Peroxidase (2) Lysozyme (3) Immunoglobulin (4) Lactoferrin

4. Endocrine function (1) The parotid secretion tube secretes parotin (2) Discover vasodilator in catheter cells (3) Growth factor

The amount of saliva is reduced Acinar degeneration, atrophy and fibrosis Fat tissue replaces acinus Sediments appear in the catheter Eosinophils in the glands: cells with decreased secretion activity, increased volume, and constriction of the nucleus in large excretion ducts