Phys 3

A person without a gallbladder: A. cannot secrete bile. B. cannot store bile. C. will have no difficulty digesting a large, fat-rich meal. D. cannot digest fats. E. cannot store lipase.

B. cannot store bile.

Regurgitation of food from the stomach into the esophagus: A. is ordinarily inhibited by the upper esophageal sphincter. B. causes irritation of the esophageal mucosa. C. is called retropulsion, and is essential for gastric digestion. D. is ordinarily prevented by the pyloric sphincter. E. is called secondary peristalsis.

B. causes irritation of the esophageal mucosa.

Which of the following processes is NOT associated with gastrointestinal function? A. digestion B. filtration C. secretion D. motility E. absorption

B. filtration

Which of the following breakfasts would likely remain in the stomach longest? A. toast, orange juice, and coffee B. fried eggs, bacon, and hash browns C. a bowl of cereal with skim milk D. a boiled egg, toast, and juice E. The type of meal has no effect on the rate of gastric emptying.

B. fried eggs, bacon, and hash browns

The killing of virus-infected or cancerous cells by the immune system is called: A. immune oversight. B. immune surveillance. C. tissue immunity. D. phagocytosis. E. hemostasis.

B. immune surveillance.

Which of the following cell types binds to antigens on plasma membranes of target cells and directly destroys the cells? A. neutrophils B. NK cells C. Cytotoxic T cells (CD8 cells) D. Helper T cells (CD4 cells) E. B cells

C. Cytotoxic T cells (CD8 cells)

Which is NOT an example of an autoimmune disease? A. AIDS B. multiple sclerosis C. myasthenia gravis D. rheumatoid arthritis E. type 1 diabetes mellitus

A. AIDS

Which of the following statements regarding hormonal regulation of gastrointestinal function is TRUE? A. An increase of H+ in the small intestine stimulates secretion of the hormone secretin, which in turn stimulates HCO3- secretion by the pancreas. B. The presence of fatty acids in the stomach stimulates secretion of CCK, which in turn stimulates enzyme secretion by cells in the antrum of the stomach. C. The presence of amino acids in the small intestine stimulates secretion of gastrin, which in turn stimulates HCl secretion by parietal cells. D. The presence of fatty acids in the small intestine stimulates the secretion of the hormone secretin, which causes contraction of the gallbladder. E. The hormone somatostatin stimulates the secretion of H+ into the lumen of the stomach.

A. An increase of H+ in the small intestine stimulates secretion of the hormone secretin, which in turn stimulates HCO3- secretion by the pancreas.

Which of the following statements regarding major histocompatibility proteins (MHCs) is TRUE? A. Class I MHCs are found on all cells of the body except erythrocytes. B. Class II MHCs are normally found in the cell membranes of bacteria. C. Cytotoxic T cells require class II MHCs to recognize foreign antigens. D. All humans have identical sets of MHC proteins. E. MHC proteins are the same thing as antibodies.

A. Class I MHCs are found on all cells of the body except erythrocytes.

Which is TRUE regarding the secretion of HCl in the stomach? A. H+ is actively transported into the gastric lumen by ATPase pumps in the mucosal membrane. B. H+ is actively cotransported into the lumen by secondary active transporters coupled to K+. C. The pH of the blood leaving the area of the parietal cells is lower than the normal ECF value of 7.4. D. H+ diffuses passively from mucosal epithelial cells into the lumen of the stomach, following Cl-. E. Cl- and HCO3- are exchanged across the luminal membrane of epithelial cells via a passive transport protein.

A. H+ is actively transported into the gastric lumen by ATPase pumps in the mucosal membrane.

Which is TRUE regarding the three phases of the control of HCl secretion? A. In the intestinal phase, an increase in osmolarity of the contents of the duodenum decreases HCl secretion. B. In the gastric phase, distension of the stomach decreases HCl secretion. C. In the cephalic phase, increased nutrient concentration in the duodenum stimulates HCl secretion. D. In the intestinal phase, increased peptide concentration in the stomach inhibits HCl secretion. E. In the gastric phase, decreased H+ concentration in the stomach inhibits HCl secretion.

A. In the intestinal phase, an increase in osmolarity of the contents of the duodenum decreases HCl secretion.

Which of the following statements regarding neural regulation of gastrointestinal function is TRUE? A. Networks of neurons in the wall of the GI tract innervate the wall's smooth muscle. B. Smooth muscle of the GI tract is innervated by both sympathetic and autonomic motor nerves. C. If the autonomic nerves to the GI tract were cut, digestion and absorption of food could no longer take place. D. The nerve plexus of the GI tract exists in a single layer, just outside of the serosa. E. There are no afferent neuronal pathways from the GI tract to the central nervous system.

A. Networks of neurons in the wall of the GI tract innervate the wall's smooth muscle.

Which of the following statements about the immune system is TRUE? A. Neutrophils, basophils, eosinophils and monocytes originate in bone marrow. B. Natural killer cells produce specific antibodies that kill bacteria and viruses. C. Mast cells are derived from monocytes. D. Plasma cells are derived from T lymphocytes. E. Macrophages are derived from neutrophils.

A. Neutrophils, basophils, eosinophils and monocytes originate in bone marrow.

Which is TRUE about gastric motility? A. The basic electrical rhythm of the gastric smooth muscle (three depolarizations per minute) is the same regardless of whether or not food is present. B. Gastric contractions are strongest in the fundus of the stomach. C. The force of contraction is decreased by gastrin and increased by enterogastrones. D. When a wave of excitation reaches the pyloric sphincter, action potentials become inhibitory and the sphincter opens wide to allow chyme to exit. E. The term, "slow waves" refer to gastric contractions, while "pacemaker" refers to gastric action potentials.

A. The basic electrical rhythm of the gastric smooth muscle (three depolarizations per minute) is the same regardless of whether or not food is present.

Which of the following statements regarding lipid digestion and absorption is TRUE? A. The presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates secretion of pancreatic enzymes. B. The presence of fatty acids in the duodenum stimulates the secretion of secretin, which in turn stimulates contraction of the gallbladder. C. The presence of fatty acids in the duodenum stimulates the secretion of gastrin, which in turn stimulates bile synthesis in the gallbladder. D. The presence of fatty acids in the duodenum stimulates emptying of the stomach. E. The presence of fatty acids in the stomach stimulates the secretion of secretin, which inhibits motility of the large intestine.

A. The presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates secretion of pancreatic enzymes.

Which of the following is NOT true about gallstones? A. They cause lactose intolerance. B. They cause pain. C. They cause impaired fat digestion. D. They cause general nutritional deficiencies. E. They cause jaundice.

A. They cause lactose intolerance.

Which is NOT true about viruses? A. They consist of a nucleic acid surrounded by a carbohydrate shell. B. They require a host cell in order to reproduce themselves. C. They may reside in a host cell for years without killing it. D. They may cause a host cell to become cancerous. E. They may have genetic information in the form of RNA.

A. They consist of a nucleic acid surrounded by a carbohydrate shell. (protein shell is correct)

Natural killer cells: A. are activated by IL-2 and interferon-gamma. B. only attack bacteria. C. cannot interact with antibodies. D. secrete interferon-gamma to activate helper T-cells. E. have primary responsibility for mass-manufacturing antibodies against foreign antigens.

A. are activated by IL-2 and interferon-gamma.

Helper T cells: A. are activated by antigen presented with MHC II proteins. B. secrete antibodies that target specific antigens. C. secrete perforin when activated. D. convert to plasma cells after they are activated. E. do not interact with MHC proteins.

A. are activated by antigen presented with MHC II

Which of the following is the most potent inhibitor (directly or indirectly) of gastric motility and emptying? A. fat in the duodenum B. acid in the stomach C. carbohydrate in the stomach D. gastrin E. distension of the stomach

A. fat in the duodenum

Lactose intolerance: A. is an inability to digest milk sugar. B. is most common in very young children. C. results from the inability to secrete insulin. D. results from removal of the gallbladder. E. is an inability to digest proteins

A. is an inability to digest milk sugar.

Colony-stimulating factors are produced by ________________ and target cells in the _______________, which results in _______________. A. macrophages; bone marrow; stimulation of proliferation of neutrophils and monocytes B. B cells; thymus; conversion of B cells to T cells C. NK cells; blood vessel walls; vasodilation D. monocytes; blood vessel walls, vasoconstriction E. basophils; bone marrow; release of histamine

A. macrophages; bone marrow; stimulation of proliferation of neutrophils and monocytes

Which of the following is secreted by the chief cells of the gastric mucosa? A. pepsinogen B. HCl C. intrinsic factor D. gastrin E. pepsin

A. pepsinogen

The primary kind of motility in the stomach during digestion of a meal is: A. peristalsis. B. segmentation. C. relaxation of the pyloric sphincter. D. mass movement. E. regurgitation.

A. peristalsis.

The type of smooth muscle contraction occurring in the esophagus during swallowing is called: A. peristalsis. B. mass movement. C. segmentation. D. distension. E. eccentric.

A. peristalsis.

Chemotaxis: A. refers to the chemical attraction of phagocytes to a site of inflammation. B. is important only for innate immune responses. C. is important only for adaptive immune responses. D. refers to the engulfing of microbes and foreign molecules by macrophages. E. refers to dilation of blood vessels by chemicals released by damaged tissue cells.

A. refers to the chemical attraction of phagocytes to a site of inflammation.

Which of the following statements regarding protein digestion and absorption is TRUE? A. Only the exocrine pancreas produces enzymes that can digest proteins. B. After absorption, the products of protein digestion are carried by blood directly to the liver. C. Pepsin digests protein mainly in the small intestine. D. The enzymes that digest protein are secreted in active form. E. Free amino acids are the only product of protein digestion that can be absorbed from the lumen into intestinal epithelial cells.

B. After absorption, the products of protein digestion are carried by blood directly to the liver.

Which of the following statements regarding blood-type incompatibilities between a mother and her fetus is TRUE? A. An Rh-negative fetus may be at risk if its mother is Rh-positive. B. An Rh-positive fetus may be at risk if its mother is Rh-negative. C. A fetus with type B blood may be at risk if its mother has type O blood. D. The risk to an Rh-positive fetus of an Rh-negative mother is lessened if she has previously carried an Rh-negative fetus. E. The greatest risk to a fetus occurs when both mother and fetus are Rh-positive.

B. An Rh-positive fetus may be at risk if its mother is Rh-negative.

Which occurs during the secretion of hydrochloric acid by gastric epithelial cells? A. There is a decrease in the pH of blood in the hepatic portal circulation. B. Bicarbonate ions are secreted into the hepatic portal circulation. C. Chloride ions are pumped from the cytosol of the gastric epithelial cells into the hepatic portal circulation blood. D. Both H+ and K+ are actively pumped from the epithelial cell cytosol into the lumen of the stomach. E. Vesicles containing H+/K+ -ATP-aseoteins are endocytosed into vesicles within the gastric epithelial cells.

B. Bicarbonate ions are secreted into the hepatic portal circulation.

Which of the following statements regarding phagocytes and phagocytosis is true? A. Macrophages, monocytes, and mast cells are phagocytes. B. Contact of phagocytes with microbes stimulates the phagocytes to release chemicals that mediate the inflammatory response. C. Phagocytosis is stimulated by the presence of proteins called rhodopsins. D. Phagocytosis is the process by which leukocytes exit the bloodstream. E. Phagocytosis is a process that only occurs within the bloodstream.

B. Contact of phagocytes with microbes stimulates the phagocytes to release chemicals that mediate the inflammatory response.

Which of the following statements regarding the secretions of immune system cells is TRUE? A. Type 2 interferons are only secreted by macrophages. B. Interleukin 2 is a cytokine secreted by most immune cells. C. Type 1 interferons are also called interferon-gamma. D. Colony-stimulating factors are secreted mainly by plasma cells. E. Antibodies are produced and secreted by macrophages.

B. Interleukin 2 is a cytokine secreted by most immune cells

Which of the following statements about the transport of the absorbed products of fat digestion is TRUE? A. Free fatty acids and monoglycerides are transported to the liver via the hepatic portal vein. B. Products of fat digestion first go to the lymph system, and then to the veins leading to the heart. C. Triglycerides are transported to the liver via the hepatic portal vein to be processed. D. Free fatty acids and monoglycerides are assembled into triglycerides before they are absorbed from the lumen of the gut into epithelial cells lining the tract. E. Products of fat digestion are absorbed in the distal portion of the ileum, bound to intrinsic factor.

B. Products of fat digestion first go to the lymph system, and then to the veins leading to the heart.

Which of the following statements regarding phagocytosis is TRUE? A. Macrophages are the only phagocytes in the tissues. B. The microbe engulfed by the phagocyte is killed by lysosomal enzymes and hydrogen peroxide. C. Phagocytosis is controlled by a negative feedback mechanism whereby phagocytes release chemicals that inhibit further phagocytosis. D. The microbe engulfed by the phagocyte is killed by the membrane attack complex (MAC). E. Antibodies found inside lysosomes attack and kill microbes that are engulfed by phagocytosis

B. The microbe engulfed by the phagocyte is killed by lysosomal enzymes and hydrogen peroxide.

Which of the following is NOT normally a route of transmission of HIV/AIDS? A. unprotected sexual intercourse with an infected partner B. kissing or contact with items contaminated by the saliva of an infected individual C. across the placenta from an infected mother to her fetus during pregnancy or delivery D. via breast milk during nursing E. transfer of contaminated blood or blood products from one person to another

B. kissing or contact with items contaminated by the saliva of an infected individual

B cells that differentiate during an initial immune response but remain dormant until being activated during a subsequent exposure to an antigen are called: A. T-cells. B. memory cells. C. macrophages. D. monocytes. E. cytokines.

B. memory cells.

What structure secretes the enzyme that breaks down starch to smaller carbohydrates? A. the esophagus B. pancreatic exocrine cells C. pancreatic duct cells D. the liver E. the large intestine

B. pancreatic exocrine cells

The primary kind of motility in the small intestine during digestion of a meal is: A. peristalsis. B. segmentation. C. receptive relaxation. D. migrating motility complex. E. mass movement

B. segmentation.

Which of the following would be most likely to cause metabolic acidosis? A. severe vomiting B. severe diarrhea C. hyperventilation D. hypoventilation E. traveling to high altitude

B. severe diarrhea

Which of the following statements regarding the activation of complement is TRUE? A. Complement is activated only as a result of innate immune responses. B. Complement is activated only as a result of adaptive immune responses. C. Complement is activated as a result of both innate and adaptive immune responses, but the activation by adaptive immune responses is more robust. D. Complement is activated as a result of both innate and adaptive immune responses, but the activation by innate immune responses is more robust.

C. Complement is activated as a result of both innate and adaptive immune responses, but the activation by adaptive immune responses is more robust.

Which of the following statements regarding digestion and absorption of carbohydrates is true? A. Carbohydrate digestion begins in the stomach. B. Lactose intolerance results from an insufficiency of the enzyme, amylase. C. Digestible polysaccharides are broken down into the monosaccharides glucose, galactose and fructose, which can be absorbed. D. Sucrose is the main form of carbohydrate that can be absorbed by active transport across the intestinal epithelium. E. Cellulose from plants is a polymer of glucose that can be easily digested and absorbed by the human GI tract.

C. Digestible polysaccharides are broken down into the monosaccharides glucose, galactose and fructose, which can be absorbed.

During the cephalic phase of gastric stimulation, which of the following does NOT occur? A. Seeing, smelling, and/or tasting food reflexly increase(s) gastric acid secretion. B. Parasympathetic stimulation of secretory cells in the gastric mucosa occurs. C. Gastrin is secreted into the gastric lumen. D. HCl is secreted into the gastric lumen. E. Pepsinogen is secreted into the gastric lumen.

C. Gastrin is secreted into the gastric lumen.

Which class of antibodies are commonly called gamma globulin? A. IgM B. IgE C. IgG D. IgA E. IgD

C. IgG

Which is TRUE regarding the immune system cells? A. Plasma cells are derived from T cells. B. Macrophages are derived from basophils. C. Macrophages are derived from monocytes. D. The immune cells found within the bloodstream are called erythrocytes. E. Neutrophils are classified as lymphoid cells.

C. Macrophages are derived from monocytes.

Which of the following statements regarding protein digestion and absorption is TRUE? A. Cells in the stomach secrete enterokinase, which breaks down proteins into smaller peptides. B. Pepsin and trypsin are proteolytic enzymes that are most active in an acid pH. C. More acid is secreted during the digestion of a high-protein meal than during the digestion of a meal containing little protein. D. The presence of peptides in the stomach inhibits secretion of gastrin. E. Proteins are too large to pass through the pyloric sphincter into the small intestine.

C. More acid is secreted during the digestion of a high-protein meal than during the digestion of a meal containing little protein.

Which of the following statements concerning secretin is correct? A. The most potent stimulus for secretin secretion is the presence of fat in the duodenum. B. Secretin is the most potent stimulus for pancreatic digestive enzyme secretion. C. Secretin is the most potent stimulus for pancreatic HCO3- secretion. D. Secretin stimulates secretion by the parietal and chief cells. E. Secretin stimulates gastrin secretion by parietal cells.

C. Secretin is the most potent stimulus for pancreatic HCO3- secretion.

Which of these correctly describes a systemic response to infection? A. Appetite generally increases compared to normal. B. The body's set point temperature is reset so that body temperature is maintained lower than normal. C. The liver retains iron and zinc so plasma levels are decreased from normal. D. There is reduced breakdown of triglycerides in adiopse tissue and a decrease in plasma free fatty acids compared to normal. E. Secretion of cortisol by the adrenal cortex is decreased.

C. The liver retains iron and zinc so plasma levels are decreased from normal.

Which is TRUE about fat-soluble vitamins? A. They must be digested to fatty acids and monoglyceride before being absorbed. B. Examples include vitamins A, B12, and D. C. Their normal absorption depends on normal secretion of bile salts. D. They are absorbed into GI capillaries and travel immediately to the liver in the hepatic portal vein, for storage. E. They don't need to be ingested because the body can manufacture all of them in sufficient quantities.

C. Their normal absorption depends on normal secretion of bile salts.

When an antigen is bound to an antibody, it binds to: A. the heavy immunoglobulin chain only. B. the light immunoglobulin chain only. C. a specific antigen-binding site formed by heavy and light chains. D. a hypervariable region of immunoglobulin DNA. E. gamma immunoglobulin only.

C. a specific antigen-binding site formed by heavy and light chains.

Which of the following is NOT secreted by the exocrine pancreas? A. bicarbonate ions B. amylase C. bile salts D. trypsinogen E. lipase

C. bile salts

Which is normally present in a subject with type O blood? A. erythrocytes carrying type A antigen B. erythrocytes carrying type B antigen C. both anti-A and anti-B antibodies in the plasma D. erythrocytes with both type A antigen and type B antigen E. plasma that has neither anti-A nor anti-B antibodies

C. both anti-A and anti-B antibodies in the plasma

Which is caused by increased levels of the hormone cholecystokinin? A. contraction of the sphincter of Oddi B. inhibition of pancreatic enzyme secretion C. contraction of the gallbladder D. secretion of HCO3- from the pancreatic duct cells E. secretion of gastric H+

C. contraction of the gallbladder

Which of the following plays a main role in stimulating the secretion of the hormone gastrin? A. the hormone secretin B. the hormone cholecystokinin (CCK) C. distention of the stomach D. an increase in [H+] in the lumen of the stomach E. histamine

C. distention of the stomach

Which of the following molecules crosses the luminal membrane of intestinal cells by facilitated diffusion? A. glucose B. lactose C. fructose D. galactose E. maltose

C. fructose

Antibodies are: A. secreted by helper T cells. B. cytokines. C. immunoglobulins. D. composed of two polypeptide chains - a heavy chain and a light chain. E. phagocytes.

C. immunoglobulins.

Bile pigments: A. are important for fat digestion. B. are formed from catabolism of the globin part of hemoglobin. C. impart color to the bile, feces, and urine. D. are amphipathic molecules that emulsify fats. E. are completely reabsorbed in the distal ileum.

C. impart color to the bile, feces, and urine.

Constipation: A. is associated with symptoms caused by accumulation of toxins present in feces. B. is caused by failure to defecate at least once a day. C. may be prevented by ingestion of foods with a high proportion of cellulose and other indigestible carbohydrates. D. results in metabolic acidosis. E. occurs in people who are lactose intolerant when they drink milk.

C. may be prevented by ingestion of foods with a high proportion of cellulose and other indigestible carbohydrates.

Cytotoxic T cells: A. secrete perforin, which kills bacteria and viruses by perforating the membrane or coat that surrounds them. B. are activated by interleukin 1. C. require Class I MHC proteins to recognize foreign antigens. D. are converted to plasma cells when activated by MHC proteins. E. secrete proteins that neutralize bacterial toxins.

C. require Class I MHC proteins to recognize foreign antigens.

During the contractions of gastric emptying: A. the stomach is induced to contract by increased sympathetic activity. B. the pyloric sphincter opens to allow stomach contents to pass quickly and completely into the duodenum. C. the pyloric sphincter closes to allow only a small amount of liquefied chyme to pass into the duodenum with each contraction of the stomach. D. the strength of stomach wall contractions is increased when the duodenum secretes cholecystokinin. E. the strongest contractions are in the antrum of the stomach because the intrinsic pacemaker frequency is fastest there.

C. the pyloric sphincter closes to allow only a small amount of liquefied chyme to pass into the duodenum with each contraction of the stomach.

Ulcers are: A. most common in the gastric mucosa. B. always caused by hypersecretion of gastric acid. C. treated by interventions that inhibit acid secretion. D. caused by removal of the gallbladder. E. most common in the large intestine.

C. treated by interventions that inhibit acid secretion.

Which occurs mainly in the small intestine? A. gastrin is secreted B. H+ is secreted from epithelial cells into the lumen C. lysozyme is secreted D. acidic chyme is neutralized E. bile salts are manufactured

D. acidic chyme is neutralized

Which applies to the classical complement pathway, but NOT to the alternative complement pathway? A. Activation of C3 results in the formation of C3b. B. There is a cascade of proteins activated, which results in the killing of microbes. C. Complement proteins serve as opsonins that facilitate phagocyte binding to microbes. D. Antibodies activate the first complement protein (C1). E. Complement activation leads to the development of a multiunit protein called the membrane attack complex (MAC).

D. Antibodies activate the first complement protein (C1).

Which of the following statements about pancreatic enzymes is FALSE? A. Trypsinogen is secreted in an inactive form. B. Pancreatic amylase digests carbohydrates. C. Pancreatic lipase digests fats. D. Except for trypsinogen, other proteolytic enzymes are secreted in active form. E. Trypsinogen is activated by enterokinase.

D. Except for trypsinogen, other proteolytic enzymes are secreted in active form.

Which of the following statements regarding complement is FALSE? A. Certain complement proteins are always circulating in the blood in an inactive state. B. Activated complement can form a membrane attack complex, which forms pores in microbe membranes. C. Activated complement can stimulate cells to secrete inflammation-mediating chemicals. D. The complement pathway is always dependent upon activation of the first complement protein, C1. E. Some activated complement proteins activate other complement proteins.

D. The complement pathway is always dependent upon activation of the first complement protein, C1.

Which of the following statements regarding the chemical mediators of inflammatory responses is NOT true? A. They may be secreted by cells residing in the area of injury. B. They may be secreted by cells that enter the affected area. C. They may be generated by enzymatic cleavage of proteins in plasma. D. They are all peptides. E. They may be chemotaxins.

D. They are all peptides.

Which does NOT accurately describe interferons? A. They are proteins produced by most cells of the body in response to infection by a virus. B. They interfere with viral replication in cells. C. They play a role in the killing of tumor cells. D. They kill bacteria by forming pores in the cell membrane. E. They bind to surface receptors on cells, and trigger cellular production of antiviral proteins.

D. They kill bacteria by forming pores in the cell membrane.

The small intestine: A. normally contain millions of bacteria that digest complex polysaccharides and produce vitamin K. B. secretes amylase, lipase, and various proteases from its epithelial cells. C. is the main site of gastrin secretion. D. absorbs a larger volume of fluid than any other region of the GI tract. E. undergoes only peristaltic contractions, both during the digestion of meals and between meals.

D. absorbs a larger volume of fluid than any other region of the GI tract.

The rationale behind the drugs used to treat HIV/AIDS, is to reduce the number of viruses present in the body to infect otherwise healthy cells. Which of these is NOT a therapy that acts in this way? A. inhibition of the reverse transcriptase enzyme B. interference with the processes involved in expression of viral nucleic acid by the host cell C. blocking an alpha protease enzyme associated with the assembly of the virus D. chemical agents directed at interruption of mitosis in host cells for the virus E. blocking the attachment and fusion of the HIV viruses with T lymphocyte host cells

D. chemical agents directed at interruption of mitosis in host cells for the virus

What two cell types are mainly responsible for graft rejection? A. B cells and helper T cells B. natural killer cells and B cells C. marcrophages and natural killer cells D. cytotoxic T cells and helper T cells E. B cells and plasma cells

D. cytotoxic T cells and helper T cells

Which type of allergy/hypersensitivity occurs independent of antibodies? A. immune-complex hypersensitivity B. immediate hypersensitivity C. cytotoxic hypersensitivity D. delayed hypersensitivity

D. delayed hypersensitivity

Which combination of substances would cause the greatest stimulation of gastric HCL secretion when applied to parietal cells? A. somatostatin, gastrin, and histamine B. acetylcholine, histamine, and somatostatin C. somatostatin and acetylcholine D. gastrin, histamine, and acetylcholine E. histamine and gastrin

D. gastrin, histamine, and acetylcholine

40. Individuals who have been infected by the Human Immunodeficiency Virus (HIV): A. always manifest symptoms early in the disease process. B. can be diagnosed only when they develop certain rare forms of cancer. C. succumb to the disease in a relatively brief period of time after infection due to massive loss of T lymphocytes. D. generally are diagnosed by detection of anti-HIV antibodies or HIV RNA in their blood. E. have normal B cell and cytotoxic T cell function.

D. generally are diagnosed by detection of anti-HIV antibodies or HIV RNA in their blood.

Cells of the immune system capable of phagocytosis include: A. macrophages, NK cells, and basophils. B. B cells, T cells, and macrophages. C. monocytes, neutrophils, and plasma cells. D. macrophages, neutrophils, and dendritic cells. E. macrophages, mast cells, and lymphocytes

D. macrophages, neutrophils, and dendritic cells.

Which of the following pathways is activated during the cephalic phase of gastrointestinal control? A. sympathetic nerves to enteric nervous system B. secretion of cholecystokinin C. secretion of secretin D. parasympathetic nerves to enteric nervous system E. short reflexes between the small intestine and stomach

D. parasympathetic nerves to enteric nervous system

Which of the following enzymes is most active at an acidic pH? A. amylase B. lipase C. trypsin D. pepsin E. chymotrypsin

D. pepsin

Bicarbonate is: A. secreted into the lumen by gastric epithelial cells and into the interstitial fluid by pancreatic duct cells. B. secreted into the lumen by pancreatic acinar cells, and into the interstitium by pancreatic duct cells. C. secreted into the lumen by pancreatic duct cells, and into the interstitium by pancreatic acinar cells. D. secreted into the interstitial fluid by gastric epithelial cells, and into the lumen by pancreatic duct cells. E. secreted into the lumen by both gastric epithelial cells and pancreatic duct cells.

D. secreted into the interstitial fluid by gastric epithelial cells, and into the lumen by pancreatic duct cells.

The main source of enzymes that cleave disaccharides into monosaccharides is: A. the pancreas. B. the liver. C. gastric secretory cells. D. the luminal membrane of epithelial cells in the small intestine. E. the salivary glands

D. the luminal membrane of epithelial cells in the small intestine.

After initial entry of bacteria into a cut in the skin, vasodilation of local blood vessels and increased capillary permeability occur. Which of the following events is NOT part of the adaptive immune response to the infection? A. antigen interaction with lymphocytes. B. production of antibodies that bind to antigens. C. B-cell differentiation into plasma cells. D. vasodilation of local blood vessels. E. activation of lymphocytes.

D. vasodilation of local blood vessels.

The immune system destroys or neutralizes: A. bacteria. B. viruses. C. nonmicrobial foreign substances. D. cancer cells that arise in the body. E. All of the choices are correct

E. All of the choices are correct

In which region(s) of the GI tract do peristaltic contractions occur? A. the small intestine B. the large intestine C. the stomach D. the esophagus E. All of these options are correct.

E. All of these options are correct.

Which of the following statements is true regarding the emulsification of fats? A. Fat emulsification requires pancreatic lipase. B. Emulsification is the splitting of triglycerides into monoglycerides and free fatty acids. C. Fat emulsification occurs mainly in the liver. D. Emulsification is the production of a chylomicron from triglycerides and protein. E. Fat emulsification requires secretion of bile salts and phospholipids by the liver.

E. Fat emulsification requires secretion of bile salts and phospholipids by the liver.

Which of these are secretions of the parietal cells of the gastric mucosa? A. HCl and pepsinogen B. pepsinogen and intrinsic factor C. gastrin and intrinsic factor D. HCl and gastrin E. HCl and intrinsic factor

E. HCl and intrinsic factor

After activation of C3 of the complement system, which of these is a role of its component part, C3b? A. It acts as an enzyme to convert nitric oxide into hydrogen peroxide. B. It causes vasodilation of local blood vessels. C. It acts as a chemotaxin for macrophages. D. It stimulates the conversion of monocytes to neutrophils. E. It acts as an opsonin that is recognized by phagocytes targeting the microbe for destruction

E. It acts as an opsonin that is recognized by phagocytes targeting the microbe for destruction

Which accurately describes lipase? A. It is mainly produced in the liver, and secreted into the small intestine. B. It emulsifies lipids. C. It is secreted by the endocrine pancreas. D. It is produced in the exocrine pancreas, and catalyzes the degradation of chylomicrons into proteins and fats. E. It catalyzes the breakdown of triglycerides into monoglycerides and free fatty acids.

E. It catalyzes the breakdown of triglycerides into monoglycerides and free fatty acids.

Which of the following statements about gastrin is TRUE? A. It is mainly secreted by cells in the epithelium of the duodenum. B. It is an enzyme that is secreted into the lumen of the stomach. C. It is a hormone that is secreted in response to sympathetic stimulation. D. It is an enzyme that breaks down proteins. E. It is a hormone that is secreted in response to the presence of peptides in the stomach.

E. It is a hormone that is secreted in response to the presence of peptides in the stomach.

Which of these is a function of intrinsic factor? A. It is secreted by salivary glands, and is necessary for digestion of vitamin B12. B. It is secreted by parietal cells in the gastric mucosa, and its main function is causing insulin release. C. It is secreted in the stomach, and its main function is activating pepsinogen into pepsin. D. It is secreted by the small intestine mucosa, and its main function is initiating the intrinsic electrical activity of the pacemaker cells in the stomach. E. It is secreted in the stomach, and a deficiency of it would cause anemia.

E. It is secreted in the stomach, and a deficiency of it would cause anemia.

Which of the following statements regarding the lymphoid organs is NOT true? A. The primary lymphoid organs are the bone marrow and thymus. B. The thymus secretes protein hormones, collectively called thymopoietins. C. Large numbers of macrophages and lymphocytes are found in the lymph nodes and spleen. D. The tonsils contain lymphocytes, macrophages, and dendritic cells that respond to microbes in food. E. Once a lymphocyte reaches a secondary lymphoid organ, it remains there for its lifetime.

E. Once a lymphocyte reaches a secondary lymphoid organ, it remains there for its lifetime.

Which of the following statements about neural control of digestion is FALSE? A. Parasympathetic stimulation is excitatory to digestion. B. Sympathetic stimulation is generally inhibitory to digestion. C. Local neural networks (nerve plexuses) regulate digestive functions. D. Nerve plexuses receive input from the autonomic nervous system E. Parasympathetic stimulation inhibits GI exocrine gland secretions

E. Parasympathetic stimulation inhibits GI exocrine gland secretions

Which is NOT true about AIDS? A. It is caused by a retrovirus. B. It is caused by a virus that contains RNA. C. It is transmitted by intimate contact with infected blood, sexual intercourse with an infected partner, or by an infected mother to her fetus or breast-fed infant. D. Certain unusual cancers such as Kaposi's sarcoma co-occur with relatively high frequency. E. The HIV virus preferentially enters and disables B cells.

E. The HIV virus preferentially enters and disables B cells.

Which of the following is NOT a part of the swallowing reflex? A. Respiration is inhibited. B. The glottis closes. C. The upper esophageal sphincter relaxes. D. The lower esophageal sphincter relaxes. E. The pyloric sphincter relaxes.

E. The pyloric sphincter relaxes.

Which is NOT true regarding antibodies? A. They are secreted by plasma cells. B. They protect against viruses by binding to them and presenting them to phagocytes. C. They protect against viruses by binding to them and neutralizing them. D. They activate complement. E. They are the main mediators of the innate immune response.

E. They are the main mediators of the innate immune response.

Which is NOT true about receptors that mediate digestive reflexes? A. They are located in the gastrointestinal tract wall. B. They include chemoreceptors, osmoreceptors, and mechanoreceptors. C. They may relay information to integrative centers in the CNS, or to the enteric plexuses. D. They may be endocrine cells. E. They only activate feedforward pathways.

E. They only activate feedforward pathways.

Which is NOT a function performed by activated macrophages? A. They perform phagocytosis. B. They secrete cell-killing chemicals. C. They present antigens to T-cells. D. They secrete cytokines involved in inflammation. E. They produce antibodies that bind to specific antigens.

E. They produce antibodies that bind to specific antigens.

Which is NOT a function performed by saliva? A. moistening and lubricating food for swallowing B. starch digestion C. enabling the sense of taste D. killing bacteria E. emulsifying lipids

E. emulsifying lipids

Iron is stored in the body mainly as a protein-iron storage complex called: A. glycogen. B. hemochromatosis. C. ferris wheel. D. transferrin. E. ferritin.

E. ferritin.

Which of these is a secretion of the endocrine portion of the pancreas? A. trypsinogen B. enterokinase C. amylase D. bicarbonate E. insulin

E. insulin

Bile is synthesized and secreted by the: A. gallbladder. B. gastric mucosa. C. pancreas. D. duodenum. E. liver.

E. liver.

After phagocytosis of a microbe, vesicles called phagosomes combine with intracellular organelles called ________________, resulting in destruction of the microbe. A. autosomes B. ribosomes C. nucleosomes D. mitochondria E. lysosomes

E. lysosomes

Segmentation of the small intestine: A. occurs only between meals, and functions to stimulate the secretion of gastrin and the resulting mass-movements that empty the large intestine. B. occurs at a rate of 3 contractions per minute throughout the small intestine, although the strength of contractions is much greater in the ileum, which has a much thicker layer of smooth muscle in its walls. C. functions mainly to prevent any forward movement of chyme, so that all digestion and absorption is complete before undigestible materials move into the jejunum. D. are peristaltic movements that sweep undigestible materials out of the small intestine between meals. E. mixes chyme with digestive enzymes, brings food molecules near the wall for absorption, and slowly moves small intestine contents toward the cecum.

E. mixes chyme with digestive enzymes, brings food molecules near the wall for absorption, and slowly moves small intestine contents toward the cecum.

Which of the following is NOT a systemic effect of IL-1 and other cytokines in response to infection or tissue injury? A. increased plasma levels of amino acids B. increased secretion of colony-stimulating factors C. decreased appetite D. secretion of acute-phase proteins by the liver E. stimulation of helper T cells

E. stimulation of helper T cells

Which correctly describes a major function of the stomach? A. the complete digestion of protein to amino acids B. maintaining an alkaline pH for the digestion of proteins C. absorption of saliva and chyme into the bloodstream D. lubricating food so it can be formed into a bolus E. storing ingested food and partially digesting macromolecules

E. storing ingested food and partially digesting macromolecules