Salivary gland

Exocrine glands that produce saliva

The salivary glands are exocrine glands responsible for the production and secretion of saliva, which is essential for the initial stages of digestion and oral health. These glands are located in and around the mouth and throat.

Anatomy

The human salivary glands are divided into three major pairs and numerous minor glands:

Major Salivary Glands

• Parotid gland: The largest of the salivary glands, located near the ear. It secretes a serous, watery fluid rich in enzymes, particularly amylase, which begins the digestion of starches.
• Submandibular gland: Located beneath the lower jaw, this gland produces a mixed serous and mucous secretion. It contributes significantly to the volume of saliva in the mouth.
• Sublingual gland: Found under the tongue, this gland primarily produces mucous secretions that help lubricate the oral cavity.

Minor Salivary Glands

Numerous minor salivary glands are scattered throughout the oral mucosa, including the lips, cheeks, palate, and tongue. These glands primarily produce mucous secretions that keep the oral cavity moist.

Physiology

Salivary glands are stimulated by both the autonomic nervous system and the presence of food in the mouth. The parasympathetic nervous system plays a dominant role in stimulating saliva production, while the sympathetic nervous system can modify the composition of saliva.

Saliva serves several functions:

• **Digestion**: Saliva contains enzymes such as amylase and lipase that initiate the breakdown of carbohydrates and fats.
• **Lubrication**: Mucins in saliva help lubricate food, facilitating swallowing.
• **Protection**: Saliva contains antimicrobial agents like lysozyme and lactoferrin, which help protect the oral cavity from pathogens.
• **Buffering**: Saliva helps maintain the pH balance in the mouth, protecting teeth from acid erosion.

Clinical Significance

Disorders of the salivary glands can lead to various clinical conditions:

• Sialolithiasis: The formation of stones within the salivary glands, often leading to pain and swelling.
• Sialadenitis: Inflammation of the salivary glands, which can be caused by infection or autoimmune conditions such as Sjögren's syndrome.
• Xerostomia: Also known as dry mouth, this condition can result from reduced saliva production due to medications, radiation therapy, or systemic diseases.
• Salivary gland tumors: These can be benign or malignant, with pleomorphic adenoma being the most common benign tumor.

Related pages

• Digestive system
• Oral cavity
• Exocrine gland
• Amylase