Saliva Flashcards
What are the compositions of saliva?
Amylase
Bicarbonate
Electrolytes
Lysozyme, IgbA
Mucin
Water
Important Functions of Water
Taste
Dissolution of nutrients
Swallowing and speech
An important function of Bicarbonate
buffer for esophageal reflux
Important function mucin
{more on cover eme}
Lubrication of bolus
Surface protection
Importance of amylase
Starch digestion
Importance of Lysozome, IgbA
Antibacterial
Importance of Electrolytes
k+ > Na+, Cl-
likely means that potassium is considered more important than sodium and chloride. This might be because potassium plays a crucial role in maintaining the electrical potential across cell membranes, particularly in nerve and muscle cells. Imbalances in potassium levels can lead to serious health issues, including abnormal heart rhythms.
Sodium and chloride are also important electrolytes, but perhaps in this context, the emphasis is on potassium due to its critical role in cellular function. Sodium is important for fluid balance and nerve function, while chloride helps maintain the body’s acid-base balance and is important for digestion.
serous component secretions of saliva contains _________.
the serous components of saliva contain ptyalin
What secretes ptyalin?
secreted mostly by parotid (since it secretes MOSTLY serous).
Function of ptyalin
ptyalin hydrolyzes starch into maltose, maltotriose, a-limit dextrin
How much dietary starch is hydrolyzed in the mouth vs in gastric fundus and body?
- Mouth: <5%
- Gastric fundus & body: 30%-40% prior to inactivation of amylase by gastric secretions
Deficiency in saliva
Xerostomia
(may cause dental caries, and ulcer)
optimal pH of ptyalin
pH 6.7
pH ptyalin is inactivated
pH <4.0
An oral pH of 7.0 is maintained by?
Salivary Buffer
Mucous components of salivary secretions contain _______.
Mucin
Compare the parotid, Submandibular gland, sublingual gland, and buccal gland secretion.
Parotid -> mostly serous
Sublingual and submandibular -> both serous and mucus
buccal -> ONLY mucus
The primary secretions in 1st stage of salivary secretion
ptyalin
mucus (mucin)
Ions
As primary secretion flows through the duct, what happens?
As primary secretions flow through the duct, Na+ is reabsorbed and K+ is secreted.
With this Na+ decreases, and K+ increases.
When Na+ is excessively reabsorbed, an electronegativity of -70mV in the ducts is created, what will this cause?
-70mV electronegativity causes Cl- to be passively reabsorbed as well. Hence, at this stage:
- Decreased Cl-
- Decreased Na+
- Increased K+
Due to Cl- reabsorption, what is secreted?
Bicarbonate (HCO3)
salivary secretion concentration in resting condition of Na+
15 mEq/L
salivary secretion concentration in resting condition of Cl-
15 mEq/L
salivary secretion concentration in resting condition of K+
30 mEq/L
