Physiology of the Mouth, Pharynx and Oesophagus Flashcards
Name 8 functions of saliva.
- Lubricates and wets food for swallowing.
- Helps with taste.
- Begins digestion of starch (via a-amylase) and lipids (via lingual lipase).
- Keeps mucosa moist.
- Cools hot food.
- Contents destroys bacteria.
- Washes away bacteria and food particles.
- Maintains an alkaline environment.
Approximately how much saliva do we produce each day?
800-1500ml.
What is the pH range of saliva?
6.2-8
What is osmosis?
The movement of water across a semi-permeable membrane from an area of low-solute concentration to high-solute concentration.
What is osmolarity?
The concentration of osmotically active particles per litre of solution (mOsm/L).
What is osmolality?
The concentration of osmotically active particles per kg of water (mOsm/kg).
What is tonicity? How is it determined?
Tonicity is a measure of the osmotic pressure gradient between two solutions separated by a semi-permeable membrane. It’s determined by the relative osmolarities of the two solutions.
Name 6 components of saliva.
- Water
- High K+, HCO3-, and Ca2+ (relative to plasma)
- Low Na+ and Cl- (relative to plasma)
- Mucous
- Digestive enzymes - salivary a-amylase, lingual lipase
- Antibacterial agents - thiocynate ions, antibodies
Why does saliva contain a high amount of HCO3-?
To maintain an alkaline environment.
Why does saliva contain a high amount of Ca2+?
To prevent calcium from moving out of the teeth down a concentration gradient.
How many main pairs of salivary glands are there? What are they?
- Parotid
- Sublingual
- Submandibular
What type of saliva is secreted by the Parotid salivary glands?
Serous saliva - watery and rich in enzymes.
What type of saliva is secreted by the Sublingual salivary glands?
Mucus saliva.
What type of saliva is secreted by the Submandibular salivary glands?
Mixed serous and mucus.
What are the minor salivary glands located on the inner sides of the cheeks?
Buccal glands.
What is the name of the minor salivary glands located towards the back of the tongue? What do they secrete?
Von Ebner’s glands of the tongue, which secrete digestive enzymes such as amylase and lipase.