Saliva and Salivary Glands

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Questions and Answers

What is the primary digestive role of saliva?

Moistening dry food for easier consumption (correct)

Hydrolyzing protein into amino acids

Facilitating the absorption of nutrients

Hydrolyzing starch into glucose

Which of the following substances does saliva contain that aids in starch digestion?

Urea

Ptyalin (correct)

Pepsin

Lipase

Which cells are primarily involved in the secretion of saliva within the salivary glands?

Epithelial cells

Ductal cells

Acini cells (correct)

Myoepithelial cells

What is one of the non-digestive roles of saliva?

Promoting oral hygiene Signup and view all the answers

Which factor is NOT associated with increased saliva flow?

Dehydration Signup and view all the answers

How does saliva contribute to thermoregulation?

By evaporating off the tongue Signup and view all the answers

What component primarily influences the isotonic nature of primary saliva?

Electrolytic concentration Signup and view all the answers

What is the main function of the striated cells found in salivary ducts?

Reabsorbing sodium and secreting potassium Signup and view all the answers

Which organic substance is primarily involved in nitrogen metabolism in mammals and is also found in saliva?

Urea Signup and view all the answers

Which gland primarily consists of serous acini?

Parotid gland Signup and view all the answers

What is the significance of the acinar arrangement of secretory cells in the salivary glands?

Allows efficient secretion into the ductal system Signup and view all the answers

Which component of saliva has antiseptic properties?

Thiocyanate ions Signup and view all the answers

What is the pH range of the final composition of saliva?

6.8 - 7.0 Signup and view all the answers

Which of the following best describes the role of the Auerbach plexus?

To control muscle contraction for gut motility Signup and view all the answers

What regulates the reabsorption of Na and secretion of K in the salivary ducts?

Aldosterone Signup and view all the answers

What concentration of potassium in saliva compared to plasma is observed?

7 times more Signup and view all the answers

What is the primary function of salivary glands in the digestive process?

Secretion of digestive juices Signup and view all the answers

Which layer of the digestive tube contains the Meissner plexus?

Submucosa Signup and view all the answers

Which type of saliva is formulated in the acini before modification occurs in the ducts?

Primary saliva Signup and view all the answers

Where does the secretion of saliva primarily occur within the digestive tract?

Mouth Signup and view all the answers

Which of the following is NOT a role of the digestive system?

Secretion of antibodies Signup and view all the answers

Which structure is commonly associated with the secretion of saliva?

Salivary gland Signup and view all the answers

Which physiological regulation primarily influences secretion in the digestive system?

Parasympathetic nervous system Signup and view all the answers

What do the accessory glands of the digestive system include?

Salivary glands, pancreas, liver Signup and view all the answers

Study Notes

### Saliva

Saliva is produced by salivary glands
Salivary glands are the parotid, submandibular and sublingual glands and include smaller buccal glands
Parotid glands are primarily serous
Sublingual glands are primarily mucous
Submandibular glands are both serous and mucous
Salivary glands are composed of acini clusters of cells
Acini contain two types of cells:
- Serous cells which secrete fluid
- Mucous cells which secrete mucus
Salivary glands also consist of ducts made of striated cells
- Striated cells actively reabsorb sodium and secrete potassium.
- Striated cells passively reabsorb chloride and exchange it for bicarbonate.

Saliva Secretion

Saliva secretion happens in two steps
- Primary saliva is produced in the acini
- Primary saliva is an active secretion done by ionic pumps
- Primary saliva is nearly isotonic to plasma
Secondary saliva is produced in the ducts
Secondary saliva is reformed by the ducts
Secondary saliva is hypotonic and slightly acidic
Saliva secretion is regulated by the nervous system:
- Parasympathetic nervous system regulates saliva secretion.
- Sympathetic nervous system controls the opposite.
- It can be conditioned (think Pavlov's dogs)
Saliva secretion is affected by:
- Quality of food
- Biological rhythms (for example people with regulated diets)
Saliva flow is increased with pregnancy and psychological disorders such as schizophrenia.
Saliva flow is decreased with age, dehydration, sleep and stress

Saliva Composition

Saliva composition depends on the type of food being eaten
Saliva contains:
- Mucus
- Water
- Ptyalin (salivary amylase)
- Enzymes
- Urea

Saliva Functions

Saliva performs digestive and non-digestive functions.
Digestive functions:
- Moistens food
- Helps dissolve food particles
- Lubricates the mouth and throat
- Aids in swallowing
- Helps stimulate taste buds and olfactory receptors.
- Breaks down starch using the enzyme ptyalin.
- Helps protect against mechanical injury
Non-Digestive Functions of Saliva:
- Helps with talking.
- Excreted to remove waste products
- Helps with immune system function
  - Protects the mouth from infection with anti-bacterial chemicals and antibodies
  - Protects the mouth from infection by breaking down bacteria
- Helps regulate body temperature
- Has endocrine functions (secretes EGF and NGF) .

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Description

This quiz covers the anatomy and physiology of saliva and its secretion through salivary glands. You'll learn about the different types of salivary glands, their cell composition, and the process by which saliva is produced and modified. Test your knowledge on this essential aspect of human biology.