Salivary Secretion

• How do the concentrations of Na+, Cl-, and HCO3- in saliva compare to plasma at low secretion rates?

  At low saliva secretion rates, saliva has significantly lower concentrations of Na+ and Cl- compared to plasma.
• What happens to the composition of saliva at high secretion rates?

  At high secretion rates, saliva composition resembles plasma, with higher concentrations of HCO3- due to ductal cell activity.
• What is the primary function of ductal cells in saliva secretion?

  Ductal cells secrete bicarbonate ions while reabsorbing sodium and chloride.
• Which cell type is primarily involved in the production of saliva?

  The primary cell type involved in saliva production is the acinar cells.
• How do ductal cells modify saliva composition based on flow rate?

  Ductal cells modify saliva composition by reabsorption and secretion depending on the flow rate.
• What occurs to Na+ and Cl- concentrations in saliva at low secretion rates?

  At low secretions, there are lower concentration levels of Na+ and Cl- compared to plasma due to ductal cell reabsorption.
• What is the effect of high secretion rates on HCO3- concentration in saliva?

  At high secretions, there is an increase in the concentration of HCO3- due to active secretion by the ductal cells.
• What is the substrate of salivary amylase (ptyalin)?

  The substrate of salivary amylase (ptyalin) is starch.
• What is the primary digestion product of salivary amylase?

  The primary digestion product of salivary amylase is maltose.
• What role does salivary amylase play in digestion?

  Salivary amylase breaks down carbohydrates into smaller sugar molecules during the initial stages of digestion in the mouth.
• What are the primary stimuli for mucus secretion in the GI tract?

  The primary stimuli for mucus secretion are the presence of food, stomach acid, irritants, and inflammation.
• Which cells are responsible for mucus secretion in the GI tract?

  Mucus is secreted from specialized cells called goblet cells located within the lining of the GI tract.
• What is the function of salivary mucus?

  The function of salivary mucus is to lubricate food for swallowing and protect the oral mucosa by creating a protective barrier.
• What are the roles of salivary mucus in oral hygiene?

  • Lubrication: creates a slippery surface for food movement during chewing and swallowing.
  • Protection: protects the oral mucosa from abrasion and irritation.
  • Antibacterial Activity: contains antimicrobial components that inhibit bacterial growth.
• What types of stimuli increase salivary secretion?

  The types of stimuli that increase salivary secretion include mechanical, gustatory, olfactory, and eating.
• What is the effect of mechanical stimuli on salivary secretion?

  Mechanical stimuli, such as chewing and biting force, increase salivary secretion.
• Which gustatory stimuli are most effective in increasing saliva secretion?

  Sour tastes are the most effective stimulus, but high concentrations of all five basic tastes can increase saliva secretion.
• How do olfactory stimuli affect salivary secretion?

  Olfactory stimuli, such as smells, can stimulate saliva secretion.
• What role do nerves play in salivary secretion?

  Both parasympathetic and sympathetic nerves stimulate saliva secretion, with parasympathetic stimulation producing watery secretion and sympathetic stimulation producing more viscous saliva.
• What are the key components of saliva important for oral hygiene?

  The key components of saliva include water, electrolytes, enzymes like amylase, mucins, and antimicrobial peptides.
• What roles do salivary secretions play in oral hygiene and heavy metal elimination?

  • Neutralize acids and cleanse the oral cavity.
  • Inhibit bacterial growth.
  • Facilitate remineralization of tooth enamel.
  • Eliminate heavy metals through binding proteins like metallothionein.
• How does water contribute to oral hygiene in saliva?

  Water allows for the dilution and washing away of food particles and debris.
• What is the role of electrolytes in saliva?

  Electrolytes like calcium, phosphate, and fluoride contribute to the remineralization process of tooth enamel.
• What is the function of amylase in saliva?

  Amylase is an enzyme that breaks down carbohydrates, aiding in digestion.
• What is the role of mucins in saliva?

  Mucins are glycoproteins that form a protective layer on the teeth, preventing bacteria from adhering.
• How does lactoferrin contribute to oral hygiene?

  Lactoferrin is an antimicrobial protein that binds to iron, inhibiting bacterial growth.
• What is the function of lysozyme in saliva?

  Lysozyme is an antimicrobial protein with direct bactericidal activity.
• What role does secretory IgA play in saliva?

  Secretory IgA is an immunoglobulin that plays a key role in immune defense against oral bacteria.