Which salivary gland secretes the most saliva

Surgery to treat a parotid gland tumor is called a parotidectomy. It requires great precision because the surgeon has to locate and operate around these important structures. Learn more about parotidectomy. About the size of a walnut, the submandibular glands are located below the jaw. The saliva produced in these glands is secreted into the mouth from under the tongue. Like the parotid glands, the submandibular glands have two parts called the superficial lobe and the deep lobe.

Nearby structures include:. Learn more about submandibular gland cancer surgery. The sublingual glands are the smallest of the major salivary glands. These almond-shaped structures are located under the floor of the mouth and below either side of the tongue. Learn more about surgery for cancers that begin in the sublingual glands.

There are hundreds of minor salivary glands throughout the mouth and the aerodigestive tract. A number of factors control the quality and quantity of saliva secreted. The control of salivary gland secretion is mediated by the autonomic nervous system ANS. All the salivary gland cells receive ANS supply.

Control of secretion is also dependent on the perception of taste and smell. The gustatory stimulus is more important than the masticatory stimulus in controlling the salivary secretion. The secretion of saliva occurs by the process of stimulus secretion coupling. This refers to the events involving release of neurotransmitter from vesicles in nerve terminals adjacent to parenchymal cells which stimulate them to discharge secretory granules, water and electrolytes as well as contraction of myoepithelial cells.

Norepinephrine activates both alpha and beta adrenergic receptors, while parasympathetic transmitter like acetylcholine activate cholinergic receptors. Alpha adrenergic receptor stimulation results in protein secretion while beta adrenergic or cholinergic stimulation results in low protein secretion and secretion of water and electrolytes.

Substance P stimulates alpha adrenergic and cholinergic secretion of saliva. The following flow chart Figure 4 shows the events associated with stimulus secretion coupling which involves the basic process of receptor stimulation which results in increase in the concentration of a secondary messenger, which will further trigger additional events leading to a cellular response [ 3 , 4 , 5 , 6 ].

Flowchart depicting sequence of events following neural stimulation. Copious watery saliva is secreted in response to parasympathetic stimulation and thicker saliva in response to sympathetic stimulation. Other factors affecting saliva composition are flow rate, circadian rhythm, duration of stimulus, nature of stimulus and diet.

During sleep very little saliva is secreted by major salivary glands and majority of the saliva secreted is by the minor salivary glands. Concentration of saliva depends on rate of flow and not on nature of stimulus [ 2 , 3 , 4 , 5 , 6 ].

Historically, it was suggested that parotid salivary gland secretes a hormone called parotin which was considered to have a protein-anabolic function and deficiency resulted in diseases such as chondrodystrophia fetalis, Kaschin-Beck disease, etc. An increase in the flow of saliva is referred to as sialorrhea ptyalism , while a decrease in the salivary flow is referred to as xerostomia dry mouth. Xerostomia is observed in menopause, patients treated by radiation therapy, old age, prolonged use of tranquilizers, amphetamines, antihypertensive and anticonvulsant drugs.

A number of systemic conditions affect the functioning of the secretion of salivary glands. Hyperthyroidism, pernicious anemia, vitamin D deficiency, multiple sclerosis and poorly controlled diabetes mellitus affect the salivary glands.

Inflammatory, infective and neoplastic diseases also disrupt the activity of salivary gland secretion. Salivary secretion is influenced by hormones. For example antidiuretic hormone facilitates water reabsorption by striated duct, aldosterone causes increased sodium reabsorption by striated duct, testosterone and thyroxine increase salivary secretion [ 2 , 8 , 9 ].

Protection: the saliva contains mucin and glycoproteins which provides it with lubricating properties and moistening the oral cavity, thus preventing friction between the oral structures during physiological functions like mastication.

The constant flow of saliva provides clearance of accumulated food debris and microorganisms. Mucins also provide thermal and chemical insulation. Proteins, glycoproteins and mucins form a coating called pellicle formation. Saliva acts as a source of calcium, phosphate, fluoride, statherin and proline rich protein which maintain the integrity of enamel and repair.

Digestion: water and mucin content of saliva aids in bolus formation during the process of mastication. Antimicrobial activity: mucins aid in providing a physical barrier to infections by preventing attachment of microorganisms to tooth and tissue surface. Presence of secretory immunoglobulin A provides immune defense. Peroxidase, lysozyme, lactoferrin, histatin, mucins, agglutinin, defensins and cathelicidin also help in providing antimicrobial activity.

Buffering: bicarbonate, phosphate, basic proteins, urea and ammonia help maintain the pH and neutralization of acids. Tissue repair: salivary glands release growth factors, trefoil proteins into saliva which aid is tissue repair and regeneration. Taste: saliva acts as a solvent in which molecules from food items can dissolve and reach the taste buds, epidermal growth factor and carbonic anhydrase VI maintains taste buds.

Role of saliva in periodontal pathology: saliva exerts a major influence on plaque initiation, maturation and metabolism. The first step in plaque formation is formation of pellicle followed by plaque formation and maturation [ 1 , 2 , 3 , 4 , 5 , 6 , 8 , 9 ]. Salivary proteins may play a role in plaque mineralization. It is indicated that esterase, pyrophosphatase, acid phosphatase and lysozyme may be involved.

Persons with heavy calculus, have higher levels of salivary glycoproteins than non-calculus formers [ 1 , 2 , 3 , 4 , 5 , 6 , 8 , 9 ]. The basic secretory units of salivary glands are clusters of cells called an acini. These cells secrete a fluid that contains water, electrolytes, mucus and enzymes, all of which flow out of the acinus into collecting ducts.

Within the ducts, the composition of the secretion is altered. Much of the sodium is actively reabsorbed, potassium is secreted, and large quantities of bicarbonate ion are secreted. Bicarbonate secretion is of tremendous importance to ruminants because it, along with phosphate, provides a critical buffer that neutralizes the massive quantities of acid produced in the forestomachs.

Small collecting ducts within salivary glands lead into larger ducts, eventually forming a single large duct that empties into the oral cavity. There are many different types of cells that make up the small little parts of the gland that produce saliva and secrete it you can see these different cell types on the diagram. Because of the variety of cell types, there are many different types of tumors and cancers that can develop in the parotid gland.

Additionally, because there are several lymph nodes inside the parotid gland, at times skin cancers over the temple, scalp and cheek areas can spread to this area; additionally, lymphomas can occur in these lymph nodes. The salivary glands are constantly working, and can be affected by many medical conditions, medications, and even not drinking enough water.

Infections and inflammation of the gland can cause it to swell up and become painful. Obstruction of the ducts, which can happen because of salivary stones or narrowing of the duct from infection, can cause the saliva to back up into the gland and lead to it to swelling up as well. If you would like to know more about the salivary glands, schedule a consultation with parotid surgeon Dr. Larian today by calling At the Center for Advanced Parotid Surgery, our team of medical professionals specializes in performing minimally invasive parotidectomy with a focus on facial nerve preservation and facial reconstruction.

It really depends upon exactly what was done during the surgery. In most cases, a brief hospital stay of four days or less may be required. In many cases, yes. In fact, it is often safer to do the surgeries concurrently because the parotid surgical procedure carefully traces the facial nerve and positions it safely. Doing a facelift at the same time lowers the chance of accidentally damaging this nerve at a later time because of its shifted position. Depending on the size of the tumor removed, there may be excess skin on one side of the face that will need to be tightened.

To maintain facial symmetry, the other side of the face may also need tightening.