The main signal in the small intestine lumen that results in increased pancreatic bicarbonate ion (hco3-) secretion is:

The main signal in small intestine for pancreatic bicarbonate ion secretion is Secretin.

When food from the stomach with acidic medium enters duodenum(first part of small intestine) it stimulates the lining of duodenum cells to release the hormone secretin.

This hormone travels via bloodstream to pancreas and stimulate to it to release bicarbonate ions.Now these ions enter duodenum and neutralise the acidic medium.

This results in the optimum pH for the enzymatic action to take place thereby promoting final digestion of protein.

events in order:

1.       vishnu schist

2. zoroaster granite

3. bass limestone

4. hakatar   shale

5. igneous intrusion

6. shinumo quartzite

7. dox sandstone

8. tapeats limestone

9. bright angel shale

10. muav limestone

11. temple butte limestone

12. redwall limestone  

nonconformity

answer: the unkar group shows angular unconformity because the layers are turned at angle.

unconformity

answer: specifically the angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled. an angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled.

disconformity

answer: the disconformities aremarked irregular lines between the sedimentaryrocks layers.