Salivary gland
From the Simple English Wikipedia, the free encyclopedia that anyone can change
The salivary glands make saliva. Saliva keeps the mouth and other parts of the digestive system wet. It also helps break down carbohydrates (with salivary amylase, formerly known as ptyalin) and keeps food wet and slippery so it can go down from the oro-pharynx to the esophagus to the stomach.
There are three main pairs of salivary glands. They are
- the parotid,
- the submandibular and
- the sublingual glands.
There are also many small glands in the tongue, cheeks, lips and palate. All of those glands make mucous.
Contents |
[change] Histology (The cells in the salivary gland)
There are two types of epithelial cells in salivary glands. They make either mucous or serous secretions. The parotid gland makes serous secretions. The submandibular and submaxillary glands have both types of cells. They make a mixture of mucous and serous.
[change] Classification(Different kinds of salivary glands)
The three types of salivary glands are serous mixed and mucous glands.
- The parotid gland is the only serous gland. This gland makes serous secretions only. It has cells called serous acini.
- The submandibular glands are mixed glands. They give serous and mucous. These glands have serous acini and mucus acini cells.
- The sublingual glands make mucus secretions. They have only mucous acini cells.
[change] Structure (How the salivary glands are built)
The glands are inside a bag, called a capsule, of connective tissue. Inside, it is made of little parts called lobules. Blood vessels and nerves go into the glands at the hilum and go out into the lobules. There are 3 main types of cells in the major salivary glands:
- Serous cells. They are shaped like a pyramid. They are joined together in a group that is shaped like a ball. The ball is called an acinus, with a small lumen in the centre.
- Mucous cells are usually shaped like a cube. They are joined together to make a tubules, which are very small tubes. These cells make glycoproteins that make saliva wet and slippery.
- Myoepithelial cells are all around the part of the gland where the saliva comes out. They can squeeze the saliva gland so the saliva comes out faster.
The small tubes go into ducts. Those ducts go into larger ducts that have little stripes on them, called striations. Those go into ducts between the lobes of the gland (called interlobar or excretory ducts). The main duct of the salivary glands then goes into the mouth.
[change] Where are the glands?
There are three salivary glands:
- The two parotid glands are near the ear (par- = next to, -otid = ear). They are the largest salivary glands.
- The sublingual gland(“sub-= under, “lingu-= tongue”) is under the tongue.
- The submandibular gland is in the shape of a “U”. It is under the chin bone which is called the mandible.
[change] Role in disease
- See mumps (parotiditis epidemica) and Sjögren syndrome.
Salivary duct calculus may block the ducts. This would cause pain and swelling of the gland.
Tumors of the salivary glands can occur. These are usually benign, but can be malignant. The most common type of benign tumor is Pleomorphic adenoma, followed by Warthin's tumor. The most common malignant tumor is Mucoepidermoid carcinoma.
[change] Diagnostic investigation
A sialogram is a radiocontrast study of a salivary duct.
[change] Other websites
| Gastrointestinal system |
|---|
| Mouth • Tongue • Salivary gland • Pharynx • Esophagus • Stomach • Pancreas • Gallbladder • Liver • Intestines: Small intestine (Duodenum • Jejunum • Ileum) • Large intestine (Cecum • Colon • Rectum) Anus |
