Pancreas and Liver - MCAT Biological and Biochemical Foundations of Living Systems
Card 1 of 120
Of the answers, which best describes bile?
Of the answers, which best describes bile?
Tap to reveal answer
Bile is the substance released from the liver that digests fats through detergent-like mechanisms. This is not to be confused with the pancreas which secretes digestive enzymes, such as trypsin.
Bile is the substance released from the liver that digests fats through detergent-like mechanisms. This is not to be confused with the pancreas which secretes digestive enzymes, such as trypsin.
← Didn't Know|Knew It →
Which of these statements about the liver is FALSE?
I. Hepatocytes make bile.
II. The blood supply to the liver is exclusively through the hepatic artery, which is a branch of the celiac trunk.
III. The liver is an important storage site for glycogen.
IV. Cirrhosis is and end stage condition of fibrosis or scarring of the liver.
V. The liver is capable of converting lipids to glucose.
Which of these statements about the liver is FALSE?
I. Hepatocytes make bile.
II. The blood supply to the liver is exclusively through the hepatic artery, which is a branch of the celiac trunk.
III. The liver is an important storage site for glycogen.
IV. Cirrhosis is and end stage condition of fibrosis or scarring of the liver.
V. The liver is capable of converting lipids to glucose.
Tap to reveal answer
Although it is true that the hepatic artery is a branch or the celiac axis, or trunk, the liver has a dual blood supply in the form of the hepatic artery and the portal vein. The latter structure brings absorbed nutrients from the small and large intestine directly back to liver cells for processing.
Although it is true that the hepatic artery is a branch or the celiac axis, or trunk, the liver has a dual blood supply in the form of the hepatic artery and the portal vein. The latter structure brings absorbed nutrients from the small and large intestine directly back to liver cells for processing.
← Didn't Know|Knew It →
Bile is essential for healthy digestion and absorbtion of fats. Where is bile made in the body and where is it stored before use?
Bile is essential for healthy digestion and absorbtion of fats. Where is bile made in the body and where is it stored before use?
Tap to reveal answer
Bile is made in the liver and stored in the gallbaldder. People can survive without a gallbladder, but having a gallbladder helps release a large amount of bile into the small intestine when it is needed most. This helps make digestion of fats much more effective.
Bile is made in the liver and stored in the gallbaldder. People can survive without a gallbladder, but having a gallbladder helps release a large amount of bile into the small intestine when it is needed most. This helps make digestion of fats much more effective.
← Didn't Know|Knew It →
In patients with diabetes, certain cells are either destroyed or limited in function. These cells are .
In patients with diabetes, certain cells are either destroyed or limited in function. These cells are .
Tap to reveal answer
Diabetes results from an autoimmune destruction (type I) or dysfunction (type II) of pancreatic beta cells.
The Islets of Langerhans in the pancreas are made of acinar cells, which secrete various essential hormones. Alpha cells secrete glucagon, while beta cells secrete insulin. Delta cells secrete somatostatin and epsilon cells secrete ghrelin. Beta cells are the most abundant acinar cell.
Diabetes results from an autoimmune destruction (type I) or dysfunction (type II) of pancreatic beta cells.
The Islets of Langerhans in the pancreas are made of acinar cells, which secrete various essential hormones. Alpha cells secrete glucagon, while beta cells secrete insulin. Delta cells secrete somatostatin and epsilon cells secrete ghrelin. Beta cells are the most abundant acinar cell.
← Didn't Know|Knew It →
Which of the following actions is not performed by the liver in order to regulate blood glucose levels?
Which of the following actions is not performed by the liver in order to regulate blood glucose levels?
Tap to reveal answer
The liver is vital in the control of blood glucose levels. It stores excess glucose by creating glycogen via the process of glycogenesis. It can also release glucose into the bloodstream by stimulating gluconeogenesis and glycogenolysis. Glycogenolysis is the process of converting glycogen back to glucose, while gluconeogenesis is the process of making glucose from non-carbohydrates.
Insulin is created in the pancreas, and is released in response to high blood sugar levels. The insulin then stimulates the liver to store glucose as glycogen.
The liver is vital in the control of blood glucose levels. It stores excess glucose by creating glycogen via the process of glycogenesis. It can also release glucose into the bloodstream by stimulating gluconeogenesis and glycogenolysis. Glycogenolysis is the process of converting glycogen back to glucose, while gluconeogenesis is the process of making glucose from non-carbohydrates.
Insulin is created in the pancreas, and is released in response to high blood sugar levels. The insulin then stimulates the liver to store glucose as glycogen.
← Didn't Know|Knew It →
Portal venous systems occur when blood exits from one capillary bed, and enters into another before first returning to the heart for re-oxygenation. Such arrangements are rare, and occur in only two main organs in mammals. Which of the following is an organ that uses a portal venous system?
Portal venous systems occur when blood exits from one capillary bed, and enters into another before first returning to the heart for re-oxygenation. Such arrangements are rare, and occur in only two main organs in mammals. Which of the following is an organ that uses a portal venous system?
Tap to reveal answer
The liver utilizes the hepatic portal system, while the hypothalamus and anterior pituitary use the hypopheseal portal system. The kidneys, spleen, and stomach all use normal circulation, by which blood passes from arterioles to capillaries and immediately back to venules for transport back to the heart.
The liver utilizes the hepatic portal system, while the hypothalamus and anterior pituitary use the hypopheseal portal system. The kidneys, spleen, and stomach all use normal circulation, by which blood passes from arterioles to capillaries and immediately back to venules for transport back to the heart.
← Didn't Know|Knew It →
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?
Tap to reveal answer
As we are told in the passage, phase I metabolism occurs by the transfer of electrons, commonly called an oxidation-reduction reaction. Phase I metabolism in the liver serves primarily to oxidize endogenous and exogenous molecules by passing electrons from a substrate to iron, and finally to oxygen. These oxidation reactions are carried out by the cytochrome P450 system and allow metabolites to become more soluble in urine for excretion. The other reactions listed are carried out by various transferases during phase II metabolism in the liver.
As we are told in the passage, phase I metabolism occurs by the transfer of electrons, commonly called an oxidation-reduction reaction. Phase I metabolism in the liver serves primarily to oxidize endogenous and exogenous molecules by passing electrons from a substrate to iron, and finally to oxygen. These oxidation reactions are carried out by the cytochrome P450 system and allow metabolites to become more soluble in urine for excretion. The other reactions listed are carried out by various transferases during phase II metabolism in the liver.
← Didn't Know|Knew It →
What is the primary purpose of the liver?
What is the primary purpose of the liver?
Tap to reveal answer
The purpose of the liver is to filter blood delivered from the systemic circulation by the hepatic artery, and from the intestines through the hepatic vein. The liver serves to use phase I, II, and III metabolism to oxidize, conjugate, and transport toxic chemicals to the urine or bile for excretion, respectively.
The purpose of the pancreas is to release enzymes for food digestion, while the purpose of the small intestine is to absorb micro- and macronutrients. Additionally, the purpose of the stomach is to breakdown larger food particles into smaller ones.
The purpose of the liver is to filter blood delivered from the systemic circulation by the hepatic artery, and from the intestines through the hepatic vein. The liver serves to use phase I, II, and III metabolism to oxidize, conjugate, and transport toxic chemicals to the urine or bile for excretion, respectively.
The purpose of the pancreas is to release enzymes for food digestion, while the purpose of the small intestine is to absorb micro- and macronutrients. Additionally, the purpose of the stomach is to breakdown larger food particles into smaller ones.
← Didn't Know|Knew It →
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 II metabolism in the liver function to change highly reactive metabolites of phase I metabolism, or to change other endogenous molecules for excretion?
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 II metabolism in the liver function to change highly reactive metabolites of phase I metabolism, or to change other endogenous molecules for excretion?
Tap to reveal answer
We are told in the passage that phase II metabolism occurs when a sugar nucleotide-amino acid derivative is affixed to a substance. Context clues are helpful for pinpointing the exact reaction taking place, as the passage provides us with an example of an enzyme that catalyzes the reaction, UDP-glucuronosyl transferase. We can infer from the answer choices that glucuronidation likely occurs using this enzyme. Furthermore, phase II metabolism in the liver is called conjugation, and uses various transferases (acetyltransferases, methytransferases, glucuronosyltransferases) to add function groups onto reactive metabolites from phase I metabolism and endogenous molecules, like bilirubin. Adding these functional groups serves to make the products more hydrophilic in order to be excreted in urine (if smaller) or bile (if larger).
We are told in the passage that phase II metabolism occurs when a sugar nucleotide-amino acid derivative is affixed to a substance. Context clues are helpful for pinpointing the exact reaction taking place, as the passage provides us with an example of an enzyme that catalyzes the reaction, UDP-glucuronosyl transferase. We can infer from the answer choices that glucuronidation likely occurs using this enzyme. Furthermore, phase II metabolism in the liver is called conjugation, and uses various transferases (acetyltransferases, methytransferases, glucuronosyltransferases) to add function groups onto reactive metabolites from phase I metabolism and endogenous molecules, like bilirubin. Adding these functional groups serves to make the products more hydrophilic in order to be excreted in urine (if smaller) or bile (if larger).
← Didn't Know|Knew It →
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.
Phase III metabolism in the liver involves what action upon modified metabolites?
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.
Phase III metabolism in the liver involves what action upon modified metabolites?
Tap to reveal answer
The passage tells us that phase III metabolism typically occurs by exocytosis. Remember that exocytosis is the transport of a molecule from within the cell to outside the cell with the help of ATP and vesicle packaging. We know that phase III metabolism must involve transport of a molecule from one side of the plasma membrane to the other. Phase III of liver metabolism is the transport of proteins that have been oxidized (phase I) or conjugated (phase II) from the hepatocyte into the bile system. Remember, in contrast to smaller, hydrophilic molecules that result from phase I or II metabolism and can be excreted into the urine, larger molecules must be transported (phase III metabolism) into the bile for excretion.
The passage tells us that phase III metabolism typically occurs by exocytosis. Remember that exocytosis is the transport of a molecule from within the cell to outside the cell with the help of ATP and vesicle packaging. We know that phase III metabolism must involve transport of a molecule from one side of the plasma membrane to the other. Phase III of liver metabolism is the transport of proteins that have been oxidized (phase I) or conjugated (phase II) from the hepatocyte into the bile system. Remember, in contrast to smaller, hydrophilic molecules that result from phase I or II metabolism and can be excreted into the urine, larger molecules must be transported (phase III metabolism) into the bile for excretion.
← Didn't Know|Knew It →
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.
Metabolism of drugs and endogenous materials for excretion occurs in which cell type?
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.
Metabolism of drugs and endogenous materials for excretion occurs in which cell type?
Tap to reveal answer
The liver is the primary site of metabolism for all exogenous drugs and endogenous substances. Substances are delivered to the liver hepatocytes by the blood and undergo phase I, phase II, and/or phase III metabolism before being excreted into the bile or back into the blood to be passed to the kidney for excretion into the urine.
Remember that phase I metabolism is oxidation (turns lipophilic molecules into hydrophilic molecules), phase II metabolism is conjugation, and phase III metabolism is transport to the bile. All phases, however, take place in the liver by function of the hepatocytes.
The liver is the primary site of metabolism for all exogenous drugs and endogenous substances. Substances are delivered to the liver hepatocytes by the blood and undergo phase I, phase II, and/or phase III metabolism before being excreted into the bile or back into the blood to be passed to the kidney for excretion into the urine.
Remember that phase I metabolism is oxidation (turns lipophilic molecules into hydrophilic molecules), phase II metabolism is conjugation, and phase III metabolism is transport to the bile. All phases, however, take place in the liver by function of the hepatocytes.
← Didn't Know|Knew It →
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.
A decrease in the extraction of a drug by the liver may be observed under which of the following conditions?
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.
A decrease in the extraction of a drug by the liver may be observed under which of the following conditions?
Tap to reveal answer
The fraction of a drug that the liver can act on depends on how much of the drug is delivered to the liver. Often, this initial metabolism is called "first pass metabolism," and serves to determine the initial dose of each drug when it is taken orally. Decreasing blood flow, increasing binding of a drug to plasma proteins, liver disease (hepatocyte death), and genetic mutations that decrease the activity of the liver metabolism enzymes will all reduce the amount of drug available for the liver to act upon, leading to a decrease in drug extraction.
The fraction of a drug that the liver can act on depends on how much of the drug is delivered to the liver. Often, this initial metabolism is called "first pass metabolism," and serves to determine the initial dose of each drug when it is taken orally. Decreasing blood flow, increasing binding of a drug to plasma proteins, liver disease (hepatocyte death), and genetic mutations that decrease the activity of the liver metabolism enzymes will all reduce the amount of drug available for the liver to act upon, leading to a decrease in drug extraction.
← Didn't Know|Knew It →
The Islets of Langerhans in the pancreas serve to secrete which product?
The Islets of Langerhans in the pancreas serve to secrete which product?
Tap to reveal answer
The pancreas has two primary purposes, acting as both an endocrine gland and an exocrine organ. Islets of Langerhans secrete the endocrine factors, while the acinar cells produce the exocrine factors of the pancreas.
The Islets of Langerhans serve to secrete insulin, which promotes the absorption of glucose from the blood into cells throughout the body. The Islets also secrete glucagon, somatostatin, and ghrelin. Pepsin is produced by chief cells in the stomach, while trypsinogen (the zymogen of trypsin) is produced by acinar cells of the pancreas. Bicarbonate is produced in response to secretin secretion by acinar cells in the pancreas.
Essentially, pancreatic hormones are released from the Islets of Langerhans, while pancreatic digestive enzymes are released from the acinar cells.
The pancreas has two primary purposes, acting as both an endocrine gland and an exocrine organ. Islets of Langerhans secrete the endocrine factors, while the acinar cells produce the exocrine factors of the pancreas.
The Islets of Langerhans serve to secrete insulin, which promotes the absorption of glucose from the blood into cells throughout the body. The Islets also secrete glucagon, somatostatin, and ghrelin. Pepsin is produced by chief cells in the stomach, while trypsinogen (the zymogen of trypsin) is produced by acinar cells of the pancreas. Bicarbonate is produced in response to secretin secretion by acinar cells in the pancreas.
Essentially, pancreatic hormones are released from the Islets of Langerhans, while pancreatic digestive enzymes are released from the acinar cells.
← Didn't Know|Knew It →
The interaction between blood pressure and kidney function in humans requires coordination by the renin-angiotensin-aldosterone system (RAAS). This system involves the dynamic interplay of the kidneys, lungs, and blood vessels to carefully regulate sodium and water balance.
A normal human kidney has cells adjacent to the glomerulus called juxtaglomerular cells. These cells sense sodium content in urine of the distal convoluted tubule, releasing renin in response to a low level. Renin is an enzyme that converts angiotensinogen to angiotensin I (AI). AI is converted to angiotensin II (AII) by angiotensin converting enzyme (ACE) in the lung.
AII stimulates aldosterone secretion in the zona glomerulosa of the adrenal gland. Aldosterone then acts to upregulate the sodium-potassium pump on the basolateral side of distal tubule epithelial cells to increase sodium reabsorption from the urine, as well as increasing potassium excretion.
Angiotensinogen is similar to other precursor molecules, which must be cleaved before they become active. Which of the following organs secretes digestive precursor molecules that must also be cleaved by proteolytic processes before they are functional?
The interaction between blood pressure and kidney function in humans requires coordination by the renin-angiotensin-aldosterone system (RAAS). This system involves the dynamic interplay of the kidneys, lungs, and blood vessels to carefully regulate sodium and water balance.
A normal human kidney has cells adjacent to the glomerulus called juxtaglomerular cells. These cells sense sodium content in urine of the distal convoluted tubule, releasing renin in response to a low level. Renin is an enzyme that converts angiotensinogen to angiotensin I (AI). AI is converted to angiotensin II (AII) by angiotensin converting enzyme (ACE) in the lung.
AII stimulates aldosterone secretion in the zona glomerulosa of the adrenal gland. Aldosterone then acts to upregulate the sodium-potassium pump on the basolateral side of distal tubule epithelial cells to increase sodium reabsorption from the urine, as well as increasing potassium excretion.
Angiotensinogen is similar to other precursor molecules, which must be cleaved before they become active. Which of the following organs secretes digestive precursor molecules that must also be cleaved by proteolytic processes before they are functional?
Tap to reveal answer
Digestive precursor molecules are secreted by both the pancreas and chief cells of the stomach. The pancreas secretes trypsinogen, which is later cleaved to the active trypsin. Chief cells in the stomach secrete pepsinogen, which is then cleaved into the active pepsin. These precursor molecules are known as zymogens.
Digestive precursor molecules are secreted by both the pancreas and chief cells of the stomach. The pancreas secretes trypsinogen, which is later cleaved to the active trypsin. Chief cells in the stomach secrete pepsinogen, which is then cleaved into the active pepsin. These precursor molecules are known as zymogens.
← Didn't Know|Knew It →
Which of the following is not a function of the liver?
Which of the following is not a function of the liver?
Tap to reveal answer
The functions of the liver are many and varied. The liver is responsible for gluconeogenesis (making new glucose), beta-oxidation of fats, detoxification of drugs and toxins via the cytochrome P450 system, removal of dead red blood cells from circulation, and the creation of blood proteins, including albumin and clotting factors.
The bone marrow is responsible for generating new red blood cells.
The functions of the liver are many and varied. The liver is responsible for gluconeogenesis (making new glucose), beta-oxidation of fats, detoxification of drugs and toxins via the cytochrome P450 system, removal of dead red blood cells from circulation, and the creation of blood proteins, including albumin and clotting factors.
The bone marrow is responsible for generating new red blood cells.
← Didn't Know|Knew It →
Of the answers, which best describes bile?
Of the answers, which best describes bile?
Tap to reveal answer
Bile is the substance released from the liver that digests fats through detergent-like mechanisms. This is not to be confused with the pancreas which secretes digestive enzymes, such as trypsin.
Bile is the substance released from the liver that digests fats through detergent-like mechanisms. This is not to be confused with the pancreas which secretes digestive enzymes, such as trypsin.
← Didn't Know|Knew It →
Which of these statements about the liver is FALSE?
I. Hepatocytes make bile.
II. The blood supply to the liver is exclusively through the hepatic artery, which is a branch of the celiac trunk.
III. The liver is an important storage site for glycogen.
IV. Cirrhosis is and end stage condition of fibrosis or scarring of the liver.
V. The liver is capable of converting lipids to glucose.
Which of these statements about the liver is FALSE?
I. Hepatocytes make bile.
II. The blood supply to the liver is exclusively through the hepatic artery, which is a branch of the celiac trunk.
III. The liver is an important storage site for glycogen.
IV. Cirrhosis is and end stage condition of fibrosis or scarring of the liver.
V. The liver is capable of converting lipids to glucose.
Tap to reveal answer
Although it is true that the hepatic artery is a branch or the celiac axis, or trunk, the liver has a dual blood supply in the form of the hepatic artery and the portal vein. The latter structure brings absorbed nutrients from the small and large intestine directly back to liver cells for processing.
Although it is true that the hepatic artery is a branch or the celiac axis, or trunk, the liver has a dual blood supply in the form of the hepatic artery and the portal vein. The latter structure brings absorbed nutrients from the small and large intestine directly back to liver cells for processing.
← Didn't Know|Knew It →
Bile is essential for healthy digestion and absorbtion of fats. Where is bile made in the body and where is it stored before use?
Bile is essential for healthy digestion and absorbtion of fats. Where is bile made in the body and where is it stored before use?
Tap to reveal answer
Bile is made in the liver and stored in the gallbaldder. People can survive without a gallbladder, but having a gallbladder helps release a large amount of bile into the small intestine when it is needed most. This helps make digestion of fats much more effective.
Bile is made in the liver and stored in the gallbaldder. People can survive without a gallbladder, but having a gallbladder helps release a large amount of bile into the small intestine when it is needed most. This helps make digestion of fats much more effective.
← Didn't Know|Knew It →
In patients with diabetes, certain cells are either destroyed or limited in function. These cells are .
In patients with diabetes, certain cells are either destroyed or limited in function. These cells are .
Tap to reveal answer
Diabetes results from an autoimmune destruction (type I) or dysfunction (type II) of pancreatic beta cells.
The Islets of Langerhans in the pancreas are made of acinar cells, which secrete various essential hormones. Alpha cells secrete glucagon, while beta cells secrete insulin. Delta cells secrete somatostatin and epsilon cells secrete ghrelin. Beta cells are the most abundant acinar cell.
Diabetes results from an autoimmune destruction (type I) or dysfunction (type II) of pancreatic beta cells.
The Islets of Langerhans in the pancreas are made of acinar cells, which secrete various essential hormones. Alpha cells secrete glucagon, while beta cells secrete insulin. Delta cells secrete somatostatin and epsilon cells secrete ghrelin. Beta cells are the most abundant acinar cell.
← Didn't Know|Knew It →
Which of the following actions is not performed by the liver in order to regulate blood glucose levels?
Which of the following actions is not performed by the liver in order to regulate blood glucose levels?
Tap to reveal answer
The liver is vital in the control of blood glucose levels. It stores excess glucose by creating glycogen via the process of glycogenesis. It can also release glucose into the bloodstream by stimulating gluconeogenesis and glycogenolysis. Glycogenolysis is the process of converting glycogen back to glucose, while gluconeogenesis is the process of making glucose from non-carbohydrates.
Insulin is created in the pancreas, and is released in response to high blood sugar levels. The insulin then stimulates the liver to store glucose as glycogen.
The liver is vital in the control of blood glucose levels. It stores excess glucose by creating glycogen via the process of glycogenesis. It can also release glucose into the bloodstream by stimulating gluconeogenesis and glycogenolysis. Glycogenolysis is the process of converting glycogen back to glucose, while gluconeogenesis is the process of making glucose from non-carbohydrates.
Insulin is created in the pancreas, and is released in response to high blood sugar levels. The insulin then stimulates the liver to store glucose as glycogen.
← Didn't Know|Knew It →