Exam 29: A: Physiology of the Digestive System

Lecithin is secreted by the liver.

The amount of fat being absorbed by the body can be determined by taking a blood sample from the hepatic portal system.

Enzymes are unique in that they can function optimally within a wide range of pH.

Hydrochloric acid converts pepsinogen into pepsin.

The names of enzymes are easy to identify because they all end in "ase."

Chief cells produce pepsin.

Lysophosphatide is a possible end product of fat digestion.

Diarrhea is one of the leading causes of infant mortality in developing countries.

Diarrhea occurs when the contents of the lower colon and rectum move at a rate that is slower than normal.

Although we eat six types of chemical substances (carbohydrates,proteins,fats,vitamins,mineral salts,and water),only carbohydrates,proteins,fats,and vitamins need to be digested.

Enterokinase converts trypsin into trypsinogen.

The hydrophilic portion of lecithin is attracted to the interior fat of the micelle.

The bolus of food is formed during the pharyngeal stage of deglutition.

Carbohydrates that are used for food are made up of one or more saccharide groups.

The last stage of deglutition is the pharyngeal stage.

During deglutition,the mouth is closed off by the soft palate and the uvula.

Both simple sugars and amino acids are absorbed into the blood in the intestinal capillaries.

To increase absorption time,the hormone cholecystokinin slows motility in the small intestine.

The main proteases found in gastric juice are pepsin and trypsin.

When fat combines with magnesium,it becomes indigestible.