Exam 29: A: Physiology of the Digestive System

Salivary glands are stimulated only by olfactory and visual stimuli.

Substances that activate proenzymes are often called kinases.

Intestinal motility includes both peristaltic contractions and segmentation.

Chylomicrons are absorbed by the blood vessels in the villi of the small intestine.

The specificity of enzyme function can be explained by the "key-in-a-lock" mode of action.

Chewing and swallowing are both considered mechanical digestion.

Although the cotransport of sodium and glucose is a passive process,it would not be possible without the active transport of sodium out of the cell.

Colipase is a substance made by the small intestine,and it functions as a coenzyme in fat digestion.

The stomach releases gastric inhibitory peptide to slow down peristalsis in the duodenum.

Gastric secretions are inhibited when chyme containing fats,carbohydrates,and a high pH is present in the duodenum.

The hydrophilic portion of lecithin is attracted to the exterior water of the micelle.

Bilirubin is found in bile and assists in micelle formation,which assists in the digestion of fats.

Amino acids are the end products of protein digestion.

During deglutition,the tongue closes off the nasopharynx.

Bicarbonates are useful in the GI tract for neutralizing hydrochloric acid.

Paracellular absorption requires the expenditure of cellular energy.

Gastrin,an enzyme that stimulates gastric secretions,is made by G-cells.

Amylases are found in saliva and in pancreatic juice.

The pancreatic duct,which connects the pancreas to the small intestines,does not carry the enzyme trypsin.

Peristalsis and segmentation both involve movement of the GI tract.