Gastrointestinal System

Nuclease and amylase are enzymes secreted by the pancreas.

It secretes mucus and absorbs the products of digestion.

Blood from the hepatic artery and the hepatic portal vein mix before returning to the heart via the hepatic vein. Choice A is true of the glomerular capillaries of the kidney, while choice D occurs in the vasa recta of the kidney medulla.

Such an investigation should have one tube that contains the enzyme (e.g. pepsin) and another lacking the enzyme, with the tubes being identical in all other respects (i.e. both containing protein dissolved in distilled water at the same pH). In this case the one(s) without the enzyme is the control.

Jejunum is before the ileum; food does not pass through the pancreas; duodenum is before the ileum.

Highest pH means the most alkaline. Blood pH is about 7.4, which is less than in the intestines. The proximal part of the duodenum will receive acidic chyme from the stomach, so its pH will be lowered by that. A is the best choice.

The cephalic phase refers to the thought and sight of food stimulating our secretions in preparation for food entering our stomach.

The liver produces many proteins including this precursor to angiotensin II.

Segmentation is “to and fro” movement about the one spot.

The digestion products of protein and carbohydrate (but not of triglycerides) are transported to the liver by the portal vein.