The salivary glands
The salivary glands are in the head and neck. They make and release a fluid called saliva. Saliva contains water, electrolyteselectrolytesA substance in the blood and other body fluids that carries an electric charge. Electrolytes are responsible for the movement of nutrients and wastes into and out of cells to keep body fluids balanced and to allow muscles to function properly., mucus and enzymesenzymesA protein that speeds up certain chemical reactions in the body.. Salivary glands are considered exocrine glands because they release saliva into ducts. Saliva enters the mouth through these ducts.
Types of salivary glands
The salivary glands are divided into major salivary glands and minor salivary glands.
Major salivary glands
The 3 pairs of major salivary glands are the parotid, submandibular and sublingual glands. They are the larger salivary glands that produce most of the saliva.
The parotid glands are the largest salivary glands. There are 2 parotid glands, one in front of each ear on either side of the face.
The submandibular glands are smaller than the parotid glands. There are 2 submandibular glands. Each gland is behind the lower jaw, just under the chin and tongue, on either side of the face.
The sublingual glands are the smallest of the major salivary glands. There are 2 sublingual glands. Each gland is deep in the floor of the mouth, on either side of the tongue. Saliva from the sublingual glands enters the mouth through many small sublingual ducts.
Minor salivary glands
There are 750–1000 minor salivary glands. They are very small. Most of them are too small to be seen with the naked eye.
About half of all minor salivary glands are on the hard palate in the roof of the mouth. Minor salivary glands are also found in the lips, cheeks, nose, sinuses around the nose (called paranasal sinuses), nasopharynxnasopharynxThe upper part of the pharynx (throat) behind the nose and above the soft palate (the back, soft part of the roof of the mouth)., larynxlarynxThe tube-shaped organ in the neck, between the pharynx (throat) and trachea (windpipe), that is part of the airway and contains the vocal cords, which produce sound. and tracheatracheaThe tube-shaped airway in the neck and chest that leads from the larynx (voice box) and branches to form the bronchi (the large tubes, or airways, that connect to each of the lungs)..
Other structures of the head and neck
Lymph nodes and the cranial nerves are other important structures in the head and neck.
There are large numbers of lymph nodes in the neck (called cervical lymph nodes). These lymph nodes are grouped by their location in the neck. Salivary gland cancers can spread to cervical lymph nodes. A neck dissection may be done to remove lymph nodes that have cancer in them or to prevent cancer from spreading to them. Find out more about cervical lymph nodes and neck dissection.
The cranial nerves control many functions in the head and neck, such as swallowing, vision, smell, hearing and eye movement. Some cranial nerves run though the major salivary glands. Sometimes a salivary gland tumour can spread to the cranial nerves. If the cranial nerves are in the treatment area, your healthcare team will try to protect these nerves as much as possible. Sometimes salivary gland tumours or treatments can damage the cranial nerves, which can lead to temporary or permanent problems.
Salivary glands play an important role in digestion because they make saliva. Saliva helps moisten food so we can swallow it more easily. It also has an enzyme called amylase that makes it easier for the stomach to break down starches in food.
Saliva also has an important role in our oral health. It prevents infections in the mouth and throat, helps to maintain healthy teeth and prevent bad breath. Saliva also moistens the oral cavity, which helps with swallowing and speaking.