SALIVA
| A | Saliva | |
| B |
Gastric secretions |
|
| C |
Jejunal secretions |
|
| D |
Colonic secretions |
Maximum potassium ions secretion is seen in which of the following secretion?
| A |
Saliva |
|
| B |
Gastric secretions |
|
| C |
Jejunal secretions |
|
| D |
Colonic secretions |
Saliva contains large quantity of potassium and bicarbonate ions. The concentration of potassium ion is about 30 mEq/L, seven times as great as in plasma. The concentration of potassium is gastric secretions is relatively low. Colon secretes only a small amount of potassium.
Ref: Guyton, 11th Ed Page 794
IgA secretion is seen in –
| A |
Tears and saliva |
|
| B |
CSF |
|
| C |
Hairs |
|
| D |
Vaginal fluid |
Ans. is ‘a’ i.e., Tears and saliva
Salivary amylase is activated by:
| A |
Sodium-Ion |
|
| B |
Chlorine Ion |
|
| C |
Potassium Ion |
|
| D |
Bicarbonate Ion |
Ans. B: Chlorine Ion
* Salivary Amylase breaks large, insoluble starch molecules into soluble starches (erythrodextrin, achrodextrin and ultimately maltose.
* Ptyalin acts on linear alpha (1,4) glycosidic linkages.
Optimum conditions for ptyalin
* Optimum pH – 5.6 -6.9
* Human body temperature-37 degrees Celsius
Presence of certain anions and activators:
* Chlorine and bromine – most effective
* Iodine – Less effective
* Sulfate and phosphate
* Least effective.
| A |
Saliva |
|
| B |
Colonic |
|
| C |
Gastric |
|
| D |
Jejunal |
Ans. is ‘a’ i.e., Saliva
