Overview of Salivary Glands

Study Notes

Overview of Salivary Glands

Salivary glands are exocrine glands that produce saliva.
They are crucial for digestion, lubrication of the mouth, and maintaining oral health.
Three pairs of major salivary glands—parotid, submandibular, and sublingual—are found in the mouth and throat region.
Numerous minor salivary glands are scattered throughout the oral mucosa.
Saliva contains water, electrolytes, enzymes (amylase, lysozyme), and mucins, contributing to important functions like starch digestion and bacterial control.

Salivary Gland Types

Major Salivary Glands:
- Parotids: Largest glands, located anterior to the ear, secreting primarily serous fluid.
- Submandibulars: Located beneath the mandible, secreting a mixture of serous and mucous components.
- Sublinguals: Located beneath the tongue, producing primarily mucous saliva.
Minor Salivary Glands: Numerous small glands located throughout the oral mucosa, also producing saliva.

Functions of Saliva

Digestive Function: Contains salivary amylase which initiates the breakdown of carbohydrates.
Lubrication: Allows smooth movement of food during mastication and swallowing.
Protection: Contains lysozyme, an antimicrobial enzyme, inhibiting bacterial growth.
Buffering: Maintains oral pH within a physiological range, preventing tooth decay.
Taste Perception: Saliva dissolves food particles allowing taste receptors to detect flavors.
Oral Hygiene Maintenance: Saliva washes away food debris and microorganisms, preventing plaque build-up.
Wound Healing: Saliva plays a role in supporting the healing of minor oral tissues.
Taste and Digestion: Contains proteins allowing taste transduction and proper food breakdown.

Regulation of Salivary Secretion

The secretion of saliva is a reflex action, initiated by signals from the parasympathetic nervous system through cranial nerves VII (facial) and IX (glossopharyngeal).
Chewing, smelling, and the taste of food stimulate this reflex.
Stress or illness can inhibit or abnormally increase salivation.
Sympathetic stimulation can also contribute to salivary secretion, although less significantly compared to the parasympathetic.
The secretion is regulated by hormones such as acetylcholine and the nervous system to adapt to varying needs.

Diseases Affecting Salivary Glands

Sialadenitis: Inflammation of the salivary glands, often caused by bacterial infection or obstruction.
Sialolithiasis: Formation of salivary stones (sialoliths), typically in the duct of the salivary gland, impeding saliva flow.
Mumps: A viral infection that can cause swelling of the parotid glands.
Sjögren's syndrome: An autoimmune disease affecting the salivary and lacrimal glands, leading to dry mouth and eyes.
Cancer: Tumours can affect the salivary glands (benign or malignant).

Diagnostic Procedures

Imaging techniques (e.g., ultrasound, CT scans, MRI) are utilized to visualize salivary glands.
Fine-needle aspiration cytology and biopsy may be performed for tissue analysis.
Measurement of salivary flow rate provides information regarding the functioning of the salivary glands.
Various blood tests measure for inflammatory markers and other diagnostic purposes.

Description

This quiz covers the anatomy and functions of salivary glands, including their types and importance in digestion and oral health. Explore the roles of major glands like parotid, submandibular, and sublingual, along with the minor salivary glands. Test your knowledge on the composition and function of saliva.