CH 23: The Digestive System

Where does the process of segmentation occur? anus esophagus stomach small intestine

How would you classify chewing food? propulsion mechanical breakdown digestion ingestion

Which of the following is least involved in the mechanical breakdown of food, digestion or absorption of nutrients? the oral cavity the small intestine the esophagus large intestine

Which of the organs listed below is involved in all of the following processes: secretion, mechanical breakdown of food, digestion and absorption? the esophagus the liver the stomach the large intestines

Peristaltic waves are ________. pendular movements of the gastrointestinal tract churning movements of the gastrointestinal tract segmental regions of the gastrointestinal tract waves of muscular contractions that propel contents from one point to another

The major means of propulsion through the alimentary canal is peristalsis. True False

The function of the hepatic portal circulation is to ________. carry toxins to the kidney for disposal through the urinary tract return glucose to the general circulation when blood sugar is low collect absorbed nutrients for metabolic processing in the liver distribute hormones throughout the body

Which of the following does NOT describe a basic regulator of digestive control? Digestive effectors are smooth muscle and glands. pH, stretch, and osmolarity are some of the inputs that can initiate digestive responses. Short reflexes act locally in the GI tract. conscious neural control

Which of the following is NOT a function of saliva? Saliva cleanses the mouth. Saliva contains enzymes that begin the chemical breakdown of proteins. Saliva dissolves food chemicals so that they can be tasted. Saliva moistens food and helps compact it into a bolus.

Which of the following inhibits salivation? being stressed or frightened ingestion of spicy foods the sight or smell of food relaxing after a meal

Where do the ducts of the submandibular salivary glands empty into the oral cavity? along the upper surface of the tongue the floor of the mouth under the tongue the vestibule near the upper molars the base of the lingual frenulum

How many total permanent teeth should an adult have, assuming none have been lost or removed? 8 16 20 32

Which teeth are best suited for cutting or nipping off pieces of food in the permanent dentition? molars incisors premolars (bicuspids) canines

Impacted wisdom teeth is a problem that is never observed in children because ______. their teeth are generally too small to become impacted the childhood lengthening of their jaw bones provides all of the deciduous teeth with lots of room to erupt through the gums they lack third molar teeth their wisdom teeth fall out before there is any opportunity for them to become impacted

Which of the following is not true of saliva? contains acids which aid in chemical digestion contains enzymes that begin the breakdown of carbohydrates moistens food and aids in compacting of the bolus cleanses the mouth

Which digestive process does NOT occur in the mouth? segmentation mechanical breakdown ingestion digestion

All of the following are true of swallowing (deglutition) except one. Select the statement that is not true of swallowing. The epiglottis assists in propelling food into the trachea. The voluntary phase of swallowing takes place within the mouth. The involuntary portion of swallowing takes place in the pharynx. The mouth, pharynx and esophagus all take part in swallowing.

Which of these structures is found in the stomach but nowhere else in the alimentary canal? a circular muscle layer a lining of columnar epithelium mucus-forming cells an oblique muscle layer

Which area of the stomach adjoins the small intestine? cardia body fundus pylorus

In the __________ phase of gastric secretion, chyme is moved into the duodenum. gastric phase intestinal reflux cephalic

Gastric juice does not typically cause a burning sensation within the stomach. But reflux of this gastric juice into the esophagus can cause a burning sensation. One reason why this occurs is that the esophagus ______. - secretes mucus that is not identical to stomach mucus - is internally lined by epithelial cells that are in direct physical contact with the contents of the esophagus - has enzymes that react with stomach acid to cause a burning sensation - None of the listed responses is correct.

All but one of the following is a function of the low pH found in the stomach. Select the description below that does not reflect a role of stomach acid. - Low pH converts pepsinogen to its active form, pepsin. - Many potentially harmful bacteria will be prevented entry to the small intestine by stomach acid. - Stomach acid denatures proteins making the polypeptide chain more accessible to pepsin digestive enzymes. - The stomach's acid catabolically breaks down foodstuffs in preparation for absorption.

Select the one response below that would not result from a drug that blocks histamine receptors in the cells lining the stomach. It would cause the release of secretin and cholecystokinin. It would raise the pH of the stomach. It would lower the activity of parietal cells. It would reduce the symptoms of heartburn

Pepsinogen, an inactive digestive enzyme, is secreted by the ________. goblet cells of the small intestine parietal cells of the duodenum Brunner's glands chief cells of the stomach

Chief cells ________. produce HCl produce pepsinogen produce mucin produce gastrin

Which vessel delivers nutrient-rich blood to the liver from the digestive tract? inferior vena cava hepatic portal vein central vein hepatic vein

Which chemical activates the transformation of trypsinogen to trypsin? enteropeptidase carboxypeptidase amylase chymotrypsin

What is a major function of pancreatic juice? neutralizing chyme entering the small intestine from the stomach acidifying the contents of the small intestine acidifying the contents of the stomach emulsifying fats by breaking them into smaller pieces

The pancreas secretes __________. cholecystokinin (CCK) procarboxypeptidase secretin bile

A doctor consulting a patient that recently has had their gall bladder removed would likely advise ________. eating foods that are low in fat fewer, but larger meals a low to no carb diet increasing unsaturated fats while eliminating trans fats in their diets

Kupffer cells are found in the liver and are responsible for removing bacteria and worn-out cells. True False

The pancreas has both an endocrine and an exocrine function. True False

What structural modification of the small intestine slows the movement of chyme through the lumen? intestinal crypts circular folds microvilli villi

Which of these best describes a lacteal? special capillaries in the villi designed for absorbing food effectively a deep pocket in the intestinal wall where endocrine and antimicrobial cells are located a lymphatic vessel designed to help introduce fats to the blood a projection of the small intestine wall designed to increase surface area

The __________ is the first segment of the small intestine. ileum colon duodenum jejunum

Which of the following is NOT a structural modification of the small intestine that increases surface area? circular folds villi microvilli rugae

Most absorption of nutrients occurs in the __________. large intestine stomach duodenum jejunum

Which of the following propels food residue over large areas of the colon three to four times a day? haustral contractions Valsalva's maneuver mass movement defecation reflex

Which of the following is the primary physiological function of the large intestine? nutrient absorption water absorption and feces elimination primary digestion of food mechanical breakdown of food

Which of the following is NOT a function of the large intestine? absorption of electrolytes absorption of water absorption of vitamins production of intrinsic factor

An effective way to medically treat diarrhea would be to use a drug that ______. increases the activity of the longitudinal layer of the muscularis increases the activity of the parasympathetic division of the ANS inhibits muscle tone in the anal sphincters inhibits the activity of the myenteric nerve plexus

A ruptured appendix is life threatening because ________. it is likely to cause massive infection of the abdominopelvic cavity loss of the appendix's function will cause an immune deficiency in the digestive system the large intestine will no longer be able to receive digested material from the small intestine it is likely to cause severe internal bleeding

Which of the following is an essential role played by large intestine bacteria? absorb bilirubin fermentation of indigestible carbohydrates produce gas synthesize vitamins C and D

Carbohydrates are digested into __________. amino acids monosaccharides nucleotides glycerol

Bile salts bind at their hydrophobic regions to large fat globules within the chyme that enters the duodenum. Bile salts break up the fat globule into smaller fat droplets. This role of bile salts is best described as ________. lipid absorption lipid digestion lipid emulsification lipid ingestion

You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal? trypsin cholecystokinin gastrin amylase

Select the correct statement about absorption. - In the rare case that intact, whole proteins are transported across the mucosal endothelium, an immune response may be generated. - Carbohydrates diffuse across the mucosal endothelium and are then actively transported into blood capillaries. - Eighty percent of ingested materials have been absorbed by the end of the large intestine. - Amino acid transport is linked to chloride transport.

Which enzyme(s) is/are responsible for the chemical breakdown of carbohydrates? nuclease proteases trypsin amylases

How are fats absorbed into the lymph? in the form of chylomicrons in the form of glycerol in the form of fatty acids and glycerol in the form of micelles

Which water-soluble vitamins are absorbed in the small intestines? vitamins C and D vitamins A and E B complex and C vitamins B complex and D vitamins