TopHat Digestive System Questions

How does excessive coffee consumption affect the stomach?

Coffee contains caffeine, which blocks the breakdown of cAMP. This acts to increase the production of stomach acid.

Which transporter allows glucose to move against a concnetration gradietn? a. GLUT1 b. GLUT2 c. GLUT5 d. SGLT1

d. SGLT1 GLUT1, 2, and 5 are glucose facilitated transporters, while SGLT1 is an active transporter.

What is the result of damage to the myenteric plexus within the wall of the GI tract? a. gastric secretions may decrease b. pain information will be relayed c. digestion will be impaired d. changes in gastric motility

d. changes in gastric motility Myo stands for muscles and the myenteric plexus controls he smooth muscle of the GI tract wall.

Bile is produced by the _____ and stored in the _______. a. gallbladder; liver b. liver; small intestine c. small intestine; liver d. liver; gallbladder

d. liver; gallbladder Bile is synthesized by the liver and stored in the gall bladder for secretion into the small intestine.

The innermost layer within the digestive tract is the _____. a. serosa b. submucosa c. mesenteries d. mucosa e. muscularis externa

d. mucosa Mucosal membranes line the insides of the mouth, nose, throat, GI system, uterus, vagina and ureter to protect those tissues against infection by pathogens.

Place the following events related to lipid digestion in order. - pancreatic lipases begin to digest triglycerides - emulsification of fats - micelles form - diffusion across luminal membrane - chylomicron enters lacteal - chylomicron forms - movement across basolateral membrane - free fatty acids enter endoplasmic reticulum - CCK stimulate gallbladder

- CCK stimulates gallbladder - emulsification of fats - pancreatic lipases begin to digest triglycerides - micelles form - diffusion across luminal membrane - free fatty acids enter endoplasmic reticulum - chylomicron forms - movement across basolateral membrane - chylomicron enters lacteal When fats enter the small intestine, CCK secretion stimulates bile salts release from the gallbladder. Bile salts emulsify fats into small lipid micelles after lipase digestion of triglycerides. Micelles are absorbed across the cell membrane where they form chylomicrons which are secreted across the cell membrane for absorption into the lacteal..

Match the following with their function. 1) enterocolic reflex 2) duodenocolic reflex 3) segmentation contraction 4) peristaltic contractions a. activates large intestine motility in response to stomach stretching b. activates large intestine motility in response to small intestine stretching c. occur infrequently in the large intestine d. carry chyme over large distances in the large intestine

1) a 2) b 3) c 4) d The enterocoelic reflex is due to stomach stretching. The duodenocolic reflex is due to duodenum stretching. Segmentation contractions occur rarely in the large intestine and peristaltic contractions can carry food throughout the GI tract.

Match each intestinal feature with its major function. features: 1) Peyer's patch 2) villi 3) goblet cell 4) endocrine cell 5) intestinal crypts functions: a. supports the immune system b. increase surface area for digestion and absorption c. produce the hormone secretin d. protects the small intestine from stomach acid and abrasion e. contains stem cells

1) a 2) b 3) d 4) c 5) e Peyer's patches are immune tissue, villi increase the surface area, goblet cells secrete mucus, endocrine cells secrete hormones, and intestinal crypts contain stem cells.

Match the following molecules with its function. molecules: 1) trypsin 2) chymotrypsinogen 3) enterokinase 4) carboxypeptidase functions: a. an exopeptidase b. an inactive endopeptidase released from pancreatic vesicles c. a peptidase that activates other peptidases d. an enzyme of the intestinal mucosa

1) c 2) b 3) d 4) 1 Trypsin is a protease that cleaves peptide fragments from other proteases activating them. Chymotrypsin is an inactive protease secreted by the pancreas. Enterokinase is found in the small intestine. Carboxypeptidase is an exopeptidase.

Why is the small intestine so long?

Both digestion and absorption are dependent on diffusion - a slow process. Digestion is also dependent on a wide range of enzymatic processes to reduce food to absorbable fragments. The long SI gives the GI tract the time it needs to carry these processes out. Herbivores (plant eaters) need an even longer SI tract to allow the breakdown of plant material by microbes.

Match each cell type with the molecule it releases. cells: G cell Parietal cell Enterochomaffin (ECL) cell D cell Vagal neuron molecules: somatostatin gastrin acetylcholine histamine hydrochloric acid

G cell - gastrin Parietal cell - hydrochloric acid ECL cell - histamine D cell - somatostatin Vagal neuron - acetylcholine The G cell secretes gastrin, the parietal cell secretes HCL, the enterochromaffin cells secretes histamine, the D secretes somatostatin and the vagal neurons secretes acetylcholine.

Why does the large intestine not contain villi and microvilli?

It is not specialized or absorption. Most nutrient absorption occurs in the small intestine.

Why are three muscles used to close the jaw but only one muscle used to open it?

Strength is needed to crush food to begin the digestive process, while opening the jaw is not usually under a load.

Why are dietary triglycerides digested to free fatty acids and glycerol, if they are then recombined to form triglycerides within the cell?

TGs cannot cross the cell membrane, while FFA can.

Why is the lumenal surface of the digestive tract lined with epithelium?

The digestive tract is in direct contact with the outside world through the food and fluids we eat and drink. It needs to protect itself in the same way as does the skin. The epithelial layer and the immune presence inside the GI tract protect against microbes that would do us harm.

Why is the stomach one of the few places within the digestive tract that has three layers of smooth muscle within its wall?

The stomach needs to mix (segmentation) as well as push food through the pyloric sphincter (peristalsis). This requires the extra layer of muscle and suggests that less mixing occurs in other parts of the digestive system.

Where do the bacteria that colonize the large intestine come from in a newborn baby?

They come from breast or bottle-feeding, or when the baby puts their fingers in their mouths.

Match the following accessory organs with their general function. organs: a) liver b) pancreas c) salivary gland d) gallbladder e) common bile duct functions: 1. produces bile 2. aids in swallowing 3. carries bile into small intestine 4. begins digestion in the mouth 5. digestive enzyme production 6. carries pancreatic secretions into duodenum 7. bile storage

a) 1 b) 5 c) 4 d) 7 e) 3 Each of these accessory organs plays a key role in digestive health and function.

Match each of the following digestive tract structures with its general function. structures: a) oral cavity b) duodenum c) colon d) esophagus e) stomach f) pharynx g) rectum functions: 1. terminal end large intestine 2. begins enzymatic digestion of proteins 3. connects pharynx to stomach 4. major site of digestion 5. major site of water absorption 6. vestigial immune structure 7. contains salivary glands 8. connects mouth to esophagus

a) 7 b) 4 c) 5 d) 3 e) 2 f) 8 g) 1 Each tissue and organ in the GI system has a specific task to enter ingest food, mechanically breakdown food into a chyme, mix it with saliva, secretions and enzymes, absorb nutrients and allow for a solid waste stream.

Swallowing is controlled by which of the following nerves? (Select all that apply). a. trigeminal b. glossopharyngeal c. oculomotor d. vagus

a, b, d Swallowing is controlled by the trigeminal, glossopharyngeal and vagus nerves.

Which of the following cranial nerves stimulates saliva production? a. glossopharyngeal b. vagus c. trigeminal d. abducens e. all of the above

a. glossopharyngeal The glossopharyngeal nerve controls saliva secretion in the mouth along with many other physiological processes in the mouth like swallowing.

Which of the following are produced in the gastric pit? a. mucus b. chyme c. alkaline buffer d. glucose

a. mucus The gastric pit has cells that produce proteases, hydrochloric acid, mucus and hormones that contract the stomach and small intestine.

Villi formation is due to contraction of cells in the mucosal layer of the digestive tract. a. true b. false

a. true Yes, contraction of smooth muscle in the GI wall causes formation of the villi.

A 22-year-old girl presents to the emergency room with nausea, vomiting, fever, and abdominal pain. On physical examination, her abdominal pain is located to the right iliac region. The pain she is experiencing is classified as rebound tenderness, meaning that when pressure is applied there is no pain, but when pressure is released there is extreme pain. Given the location of the pain and the presentation, what would be the presumptive diagnosis? a. ectopic pregnancy b. appendicitis c. ovarian cyst d. prostatitis

b. appendicitis The appendix is located in the right iliac region. Nausea, vomiting, fever, and rebound tenderness in that region are all hallmark characteristics of appendicitis. It would be rare to find an ectopic pregnancy in the iliac region and would a constant pain, not rebound tenderness. Her symptoms were made worse after meals.

What type of contraction pushes food through the digestive tract? a. segmentation b. peristalsis c. sphincter d. circular

b. peristalsis Segmentation contractions mix food with secretions and peristaltic contractions push food through the GI tract.

Acid formation in the stomach is a result of _______. a. absorption b. secretion c. peristaltic contractions d. segmentation contractions

b. secretion Secretion is the movement of solutes out of the cell and absorption into the cell.

Which of the following is most rapidly cleared from the stomach after eating? a. fats b. proteins c. carbohydrates

c. carbohydrates Carbohydrates are readily cleared from the stomach, while fat and protein digestion takes much longer time.

Which of the following might be a consequence of bariatric surgery, where a "band" is placed around the stomach in order to reduce its volume? a. the stomach would behave in the same way b. meals must be consumed more frequently because digestion occurs more rapidly c. digestion would be decreased and fewer nutrients would be absorbed d. the stomach will no longer be capable of peristaltic contractions

c. digestion would be decreased and fewer nutrients would be absorbed If the gastric band is placed where indicated in the figure, the movement of food from the esophagus to the stomach will be slowed.

During which phase of swallowing does food enter the stomach? a. voluntary phase b. pharyngeal phase c. esophageal phase

c. esophageal phase Once food has entered the esophagus, contractions of the wall drive food into the stomach.

A 43-year-old man presents to the emergency room one clear Tuesday morning complaining of severe pain in his epigastric and umbilical regions. He describes the pain as a burning sensation that began as he was sitting in rush hour traffic. He was concerned that he may be having a heart attack, so he got to the hospital as fast as he could. Upon further investigation, his physician discovers that this is not the first time he has experienced this pain. He has frequent nausea and occasional vomiting, but notices that the pain is worse between meals. He has a high-stress job and takes antacids regularly for heartburn. He notes that during the last month, he has been very tired and has had dark-colored stools What is a possible diagnosis? a. heart attack b. gallbladder disease c. peptic ulcer d. pancreatitis

c. peptic ulcer All of the symptoms as well as location of the pain are indicators for a peptic ulcer. The patient had heartburn for months and was in a high stress job. The dark colored stool was caused by the break-down of red blood cells in the digestive tract. He had a bleeding ulcer.

What can you deduce from the fact that the large intestine wall is composed of simple columnar epithelia? a. the large intestine is the major site of digestion of small peptides into single amino acids b. the large intestine is the major site of carbohydrate absorption c. water absorption by the large intestine does not require plicae d. the large intestine is the major site of acid and enzyme secretion

c. water absorption by the large intestine does not require plicae Since the large intestine is predominantly responsible for water reabsorption, this indicates that water reabsorption does not need plicae.

Place the following regions of the stomach in the order they would be encountered by a food molecule. fundus body pyloric cardiac

cardiac fundus body pyloric The top of the stomach is the cardiac region near the heart, followed by the fundus, body and pyloric regions next to the duodenum.

Which of the following does not occur during the cephalic phase? a. saliva secretion in the mouth b. stomach growling c. secretion of mucus in the stomach d. release of secretin from the small intestine

d. release of secretin from the small intestine During the cephalic phase, the presence or aroma of food prepares the stomach for ingestion. Secretin is only secreted by the presence of food in the small intestine.

A 34-year-old woman calls her family doctor late one evening asking for help because she is having severe pain on the right side of her face that started while she was having dinner. She described the pain as a muscle spasm followed by an excruciating, stabbing pain. Her doctor asked if she had any sour candy nearby and she did, so her doctor asked her to put a piece in her mouth while they were talking. In no time, she began to experience intense pain in the same area of her face as before. What structure(s) in her mouth are the cause of the intense pain? a. teeth b. tonsils c. uvula d. salivary gland

d. salivary gland Putting the sour candy in her mouth stimulated the salivary glands to release their enzymes to begin digestion. The parotid gland lies just anterior to the ear on each side of the face and the ducts empty into the oral cavity. Placing a food item in the mouth stimulated the parotid gland to release its contents. In this case, there was a stone blocking the parotid duct, leading to a backup of saliva. The backup causes the smooth muscle in the parotid duct to constrict more in an attempt to clear the blockage. This intense muscular contraction, along with the stone itself, were causing the pain on the side of her face.

The intestinal phase is triggered by __________. a. the sight, smell, and taste of food b. the presence of food in the stomach c. the secretion of hormones by the pancreas d. the presence of chyme in the small intestine

d. the presence of chyme in the small intestine The intestinal phase is triggered by food in the small intestine.

Arrange the following in the order they would be encountered by an ingested food molecule: hepatic vein hepatocytes hepatic portal vein sinusoid central vein vena cava duodenal mucosa systemic artery right atrium of heart

duodenal mucosa hepatic portal vein sinusoid hepatocytes central vein hepatic vein vena cava right atrium of heart systemic artery Absorbed food needs to pass through the GI wall into the hepatic portal blood flow to the liver. In the liver the nutrients and blood flow over the sinusoids where hepatocytes process the nutrients. Nutrients leave through the central vein to the hepatic vein back to systemic blood flow.

Which of the following is not a normal function of the large intestine? a. microbiome fermentation of starches to small organic molecules b. inhibition of the growth of pathogenic bacteria c. absorption of water d. microbiome metabolism of sterols and steroids e. absorption of nutrients

e. absorption of nutrients Nutrients are absorbed in the small intestine, only water is absorbed by the large intestine.

Which of the following are secreted into the large intestine? a. HCl b. pepsinogen c. pepsin d. CO2 e. mucus

e. mucus The large intestine secretes mucus and not the enzymes and acids needed for protein digestion.

Arrange the teeth in the order they would be encountered, starting at the midsagittal plane and moving laterally. molar canine incisor pre-molar

incisor canine pre-molar molar The front teeth are incisor teeth, followed by canine, premolar and finally molar teeth.

Rank the following structures in order from smallest to largest. microvilli villi plicae

microvilli villi plicae The smallest structure is the microvilli, followed by villi and then plicae.

Place the tissue layers of the digestive tract in the order you would encounter them moving from the lumen toward the abdominal cavity. muscularis mucosa mucosal epithelium serosa myenteric plexus submucosa longitudinal layer of smooth muscle circular layer of smooth muscle lamina propria

mucosal epithelium lamina propria muscularis mucosa submucosa circular layer of smooth muscle myenteric plexus longitudinal layer of smooth muscle serosa Moving from the inside of the GI tract outward, one starts with mucosal layer and ends with the connective tissue serial layers connected to the walls of the peritoneal cavity.

Place the following digestive tract structures in the order they would be encountered by an ingested food molecule. stomach ileum pharynx cecum transverse colon esophagus duodenum ascending colon descending colon jejunum

pharynx esophagus stomach duodenum jejunum ileum cecum ascending colon transverse colon descending colon The GI system is a complex collection of tissues and organs that acts in an dis-assembly line manner to liberate nutrients from the food we eat.