Which of the following cell types in the stomach is not necessary for digestive purposes?

Gastric emptying (the passage of stomach contents to the small intestine) is regulated by which sphincter of the gastrointestinal system?

In the human body, the colon primarily absorbs __________.

Which of the following is false regarding the large intestine?

I. The majority of digestion occurs in the large intestine

II. The large intestine contains microbes that have a symbiotic relationship with humans

III. The large intestine has a lower concentration of hydrogen ions than the stomach

Which of the following is true of intestinal function?

Which of the following is not a function of the human gastrointestinal system?

A renal afferent arteriole has a larger radius than the efferent arteriole. What is the effect of this larger radius on the function of the kidney?

A renal afferent arteriole has a larger radius than the efferent arteriole. What is the effect of this larger radius on the function of the kidney?

The liver primarily serves to help detoxify both endogenous and exogenous substances from the blood and intestines. Once blood from the intestines (delivered by the portal vein) or from the systemic circulation (delivered by the hepatic artery) enters the liver, it is filtered over liver cells called hepatocytes. Endogenous substances, such as bilirubin, and exogenous substances, such as drugs, are taken up by transporters on hepatocytes and undergo three phases of metabolism. The three phases allow the transported compound to be detoxified by a method of electron transfer (phase I), by addition of amino acid derivatives (phase II), and finally by exocytosis from the hepatocyte into the bile (phase III). The bile is then transported into the small intestine, and finally excreted from the body.

Amino acid derivatives are often taken from the Krebs cycle, added to sugar nucleotides, and transferred to molecules for detoxification. A common example of an enzyme responsible for this is UDP-glucuronosyl transferase.

How does phase I metabolism in the liver, conducted primarily by the cytochrome P450 system, serve to change an exogenous drug?

The liver primarily serves to help detoxify both endogenous and exogenous substances from the blood and intestines. Once blood from the intestines (delivered by the portal vein) or from the systemic circulation (delivered by the hepatic artery) enters the liver, it is filtered over liver cells called hepatocytes. Endogenous substances, such as bilirubin, and exogenous substances, such as drugs, are taken up by transporters on hepatocytes and undergo three phases of metabolism. The three phases allow the transported compound to be detoxified by a method of electron transfer (phase I), by addition of amino acid derivatives (phase II), and finally by exocytosis from the hepatocyte into the bile (phase III). The bile is then transported into the small intestine, and finally excreted from the body.

Amino acid derivatives are often taken from the Krebs cycle, added to sugar nucleotides, and transferred to molecules for detoxification. A common example of an enzyme responsible for this is UDP-glucuronosyl transferase.

How does phase I metabolism in the liver, conducted primarily by the cytochrome P450 system, serve to change an exogenous drug?