Oral Histology: Salivary Glands

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Questions and Answers

What is the percentage of water in saliva?

99% or more (correct)

95% or more

90% or more

85% or more

Which of the following enzymes is NOT a constituent of saliva?

Pepsin (correct)

Esterase

Amylase

Lysozyme

What is the main function of serous cells?

Synthesis of proteins and polysaccharides (correct)

Protein degradation

Regulation of pH

Synthesis of mucins

What is the typical shape of a serous cell?

Pyramidal Signup and view all the answers

Which of the following is NOT an electrolyte found in saliva?

Cu Signup and view all the answers

What is the pH range of saliva?

6.4 to 7.4 Signup and view all the answers

What type of cells are myoepithelial cells?

Non-secretory Signup and view all the answers

What collects the secretion of the terminal secretory units?

Intercaleted ducts Signup and view all the answers

What is the primary function of secretory organelles in serous cells?

Protein synthesis and glycosylation Signup and view all the answers

What is the characteristic of zymogen granules in serous cells?

Formed by glycolated proteins Signup and view all the answers

What is another name for Myoepithelial cells?

Basket Cell Signup and view all the answers

How do secretory granules in serous cells release their contents into the lumen?

By fusing with the plasma membrane Signup and view all the answers

What is the primary function of Myoepithelial cells?

Support and facilitate secretion by contracting Signup and view all the answers

Where are Myoepithelial cells typically found?

Inside the basal lamina of the secretory units and the initial part of the duct system Signup and view all the answers

What is the function of mucous cells in the salivary gland?

Lubrication and protection of oral tissue Signup and view all the answers

What is the function of Intercalated ducts?

All of the above Signup and view all the answers

What is the characteristic of the nucleus in mucous cells?

Small and flat, situated in the basal region Signup and view all the answers

What type of cells line the Striated ducts?

Columnar epithelial cells Signup and view all the answers

What is the difference between mucous and serous secretions?

Mucous secretions have less enzymatic activity Signup and view all the answers

What is unique about the nuclei of Striated duct cells?

They are large and centrally placed Signup and view all the answers

What is the function of serous cells in the salivary gland?

Synthesis, transportation, and storage of protein-rich material Signup and view all the answers

What is the function of Striated ducts?

Modification of saliva composition Signup and view all the answers

What is the characteristic of mucous endpieces?

Contain large amounts of carbohydrates Signup and view all the answers

What is the result of Myoepithelial cell contraction?

Ejection of preformed saliva Signup and view all the answers

What is a characteristic of the cytoplasm of striated duct cells?

It shows prominent striation at the basal ends of the cells perpendicular to the basal surface Signup and view all the answers

What is a function of ductal cells in striated ducts?

Synthesis and secretion of glycoproteins like epidermal growth factor and kallikrein Signup and view all the answers

What is a function of striated ducts?

Electrolyte reabsorption Signup and view all the answers

What is a characteristic of terminal excretory ducts?

They are lined by true stratified squamous epithelium Signup and view all the answers

What is the location of mucous goblet cells and ciliated cells?

In the terminal excretory duct Signup and view all the answers

What is the composition of the ground substance in the connective tissue of salivary glands?

Glycoproteins and proteoglycans Signup and view all the answers

What is the function of plasma cells in salivary glands?

Production of immunoglobulins Signup and view all the answers

What is the first step in the development of salivary glands?

Formation of an epithelial bud from the oral epithelium Signup and view all the answers

What is the primary function of salivary glands?

To produce saliva that provides primary natural protection for the teeth and soft tissues of the oral cavity Signup and view all the answers

How much saliva is produced daily by a healthy adult person?

1000-1500 ml Signup and view all the answers

What percentage of saliva is produced by the submandibular salivary gland?

60% Signup and view all the answers

What is the location of minor salivary glands?

In the submucosal layer Signup and view all the answers

What is the role of connective tissue in salivary glands?

It forms a capsule around the gland and extends into it, dividing groups of excretory units and ducts into lobes and lobules Signup and view all the answers

What is the resting flow rate of whole saliva?

0.2 to 0.4 ml per minute Signup and view all the answers

What is the consequence of a deficiency of salivary secretion?

Difficulty in eating, speaking, and swallowing Signup and view all the answers

What is the composition of saliva?

A balanced secretion with various organic and inorganic substances Signup and view all the answers

Study Notes

Salivary Glands

Salivary glands are exocrine glands whose secretions flow into the oral cavity.
There are three pairs of major salivary glands: parotid, submandibular, and sublingual, located outside the oral cavity, with ducts that discharge their secretions into the oral cavity.
Minor salivary glands are located in various parts of the oral cavity, typically in the submucosal layer, with short ducts opening directly onto the mucosal surface.

Structure of Salivary Glands

The parenchymal elements of the glands are derived from the oral epithelium and consist of terminal secretory units leading into ducts that mainly open into the oral cavity.
The connective tissue (C.T.) forms a capsule around the gland and extends into it, dividing groups of excretory units and ducts into lobes and lobules.
The C.T. contains blood and lymph vessels and nerves that supply the gland.

Functions of Salivary Glands

The production and secretion of saliva is the most important function of salivary glands.
Saliva contains various organic and inorganic substances that provide primary natural protection for the teeth and soft tissues of the oral cavity.

Composition of Saliva

Saliva is a complex fluid comprising approximately 99% water.
Organic constituents of saliva include enzymes (amylase, ribonuclease, kallikrein, esterase, histatin, cystatin, and peroxidase), immunoglobulins (IgG and IgM), and other factors like blood clotting factors, amino acids, urea, uric acid, and glucose.
Electrolytes present in saliva include Na, Ca, Cl, HCO3, and HPO4, as well as Mg, SO4, F, ScN, and I in smaller concentrations.

Cell Types in Salivary Glands

Serous cells: specialized for synthesizing, storing, and secreting proteins, with a pyramidal shape and a broad base adjacent to the C.T. stroma and a narrow apex forming part of the lumen of the end piece.
Mucous cells: similar to serous cells, but with a larger lumen and producing secretions with little or no enzymatic activity, serving mainly for lubrication and protection of oral tissues.
Myoepithelial cells (basket cells): contractile epithelial cells with no secretory function, supporting secretory units and facilitating secretion by contracting and causing the ejection of preformed saliva.

Ductal System of Salivary Glands

The ductal system comprises a network of small ducts that unite to form larger ducts, including intercalated ducts, striated ducts, and excretory or collecting ducts.
Intercalated ducts: connect the terminal secretory units to the larger ducts, with cells that modify the composition of saliva by secretory and resorptive processes.
Striated ducts: lined by tall columnar epithelial cells with prominent striation at the basal ends of the cells, with functions including electrolyte reabsorption and protein secretion.
Terminal excretory ducts: the ducts through which salivary fluid from the glands is secreted into the oral cavity, with characteristics changing from pseudostratified columnar epithelium to true stratified squamous epithelium.

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Description

This quiz covers the basics of salivary glands, including their location, function, and types. Learn about the major and minor salivary glands and their role in oral health.