Biology Chapter 23: Digestive System Flashcards

Questions and Answers

Which of these options is responsible for gallbladder contraction?

A significant amount of enzyme secretion by the intestinal mucosa

Cholecystokinin (CCK), an intestinal hormone responsible for gallbladder contraction (correct)

Secretions from the spleen that contain all enzymes necessary for complete digestion

Bile salts that help emulsify carbohydrates

Which statement about absorption is correct?

Carbohydrates diffuse across the villus epithelium 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.

If intact proteins are transported across the villus epithelium, an immune response may be generated. (correct)

Which statement about electrolyte absorption is true?

Iron and calcium are absorbed mostly by the duodenum. (correct)

Potassium moves across the epithelium by active transport.

Chlorine ion absorption is coupled to glucose and amino acid transport.

If vitamin B is not present, calcium is not absorbed.

Which gland is active in digesting high-fat foods like french fries and ice cream?

The pancreas Signup and view all the answers

What occurs after ingesting a high-fat meal?

Bile would be released from the gallbladder to emulsify the fat in the duodenum. Signup and view all the answers

The mucosa of the developing alimentary tube comes from which germ layer?

Endoderm Signup and view all the answers

A baby with projectile vomiting may have which condition related to gastric juice loss?

Alkalosis Signup and view all the answers

Which hormone inhibits gastric secretion?

Secretin Signup and view all the answers

Which of these is not part of the splanchnic circulation?

Inferior vena cava Signup and view all the answers

Which of the following is not a component of saliva?

Nitric oxide Signup and view all the answers

Which antibody-mediated response restricts pathogens in the large intestine?

A Signup and view all the answers

ASCITES is the abnormal accumulation of fluid within the ________.

peritoneal cavity Signup and view all the answers

BARRETT'S ESOPHAGUS is a pathological change in the epithelium of the lower esophagus from ________ to a metaplastic columnar epithelium.

stratified squamous Signup and view all the answers

What is bruxism?

Grinding or clenching of the teeth. Signup and view all the answers

What behavior is associated with bulimia?

Binge-purge behavior. Signup and view all the answers

What is dysphagia?

Difficulty swallowing. Signup and view all the answers

What does endoscopy refer to?

Visual examination of the internal organs. Signup and view all the answers

What is enteritis?

Inflammation of the intestine. Signup and view all the answers

What is hemochromatosis?

A blood disorder in iron metabolism. Signup and view all the answers

What is ileus?

All GI tract movement stops. Signup and view all the answers

What are wavelike smooth muscle contractions that move foodstuffs through the alimentary tube called?

Peristalsis Signup and view all the answers

What is the chemical or mechanical process of breaking down foodstuffs called?

Digestion Signup and view all the answers

What is the enzymatic breakdown of any type of food molecule known as?

Hydrolysis Signup and view all the answers

What is the process by which the products of digestion pass through the lumen of the gastrointestinal tract into the blood or lymph?

Absorption Signup and view all the answers

The mechanical and chemical receptors that control digestive activity are located ________.

in the walls of the tract organs Signup and view all the answers

The function of the hepatic portal circulation is to ________.

collect absorbed nutrients for metabolic processing or storage Signup and view all the answers

The chemical and mechanical processes of food breakdown are called ________.

digestion Signup and view all the answers

When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. This series of reactions is called ________.

chemical digestion Signup and view all the answers

The sheets of peritoneal membrane that hold the digestive tract in place are called ________.

mesenteries Signup and view all the answers

From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. Arrange them in order from the lumen.

mucosa, submucosa, muscularis externa, and serosa Signup and view all the answers

Which of the following is not a factor that helps create the stomach mucosal barrier?

rennin Signup and view all the answers

What part of the tooth bears the force of chewing?

enamel Signup and view all the answers

The capillaries that nourish the epithelium and absorb digested nutrients lie in the ________.

lamina propria Signup and view all the answers

Which hormone causes an increased output of enzyme-rich pancreatic juice and stimulates gallbladder contraction to release bile?

cholecystokinin CCK Signup and view all the answers

Choose the incorrect statement regarding bile.

Bile contains enzymes for digestion. Signup and view all the answers

The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplishes this task?

plicae circulares and intestinal villi Signup and view all the answers

Select the statement that is true concerning primary teeth.

There are 20 primary teeth, and by 24 months of age most children have all 20. Signup and view all the answers

Which of the following is true concerning the number and type of permanent teeth?

There are 32 permanent teeth, and the wisdom teeth are the last to emerge. Signup and view all the answers

Which of the following is not true of saliva?

contains enzymes that begin the breakdown of proteins Signup and view all the answers

The salivary glands are composed of which two types of secretory cells?

serous cells and mucous cells Signup and view all the answers

The solutes contained in saliva include ________.

electrolytes, digestive enzyme, mucin, lysozyme, wastes, and IgA Signup and view all the answers

In addition to storage and mechanical breakdown of food, the stomach ________.

initiates protein digestion and denatures proteins Signup and view all the answers

Chyme is created in the ________.

stomach Signup and view all the answers

Hydrochloric acid is secreted by which of the secretory cells of the stomach?

parietal cells Signup and view all the answers

Gastrin, histamine, endorphins, serotonin, cholecystokinin, and somatostatin are hormones or paracrines that are released directly into the lamina propria. Which of the following cell types synthesize and secrete these products?

enteroendocrine cells Signup and view all the answers

There are three phases of gastric secretion. The cephalic phase occurs ________.

before food enters the stomach and is triggered by aroma, sight, or thought Signup and view all the answers

Peristaltic waves are ________.

waves of muscular contractions that propel contents from one point to another Signup and view all the answers

Gastrin is a digestive hormone that is responsible for the stimulation of acid secretions in the stomach. These secretions are stimulated by the presence of ________.

protein and peptide fragments Signup and view all the answers

Pepsinogen, a digestive enzyme, is secreted by the ________.

chief cells of the stomach Signup and view all the answers

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

amylase Signup and view all the answers

The ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively, unite to form the ________.

hepatopancreatic ampulla Signup and view all the answers

The enzymatic breakdown of any type of food molecule is called ________.

hydrolysis Signup and view all the answers

Short-chain triglycerides found in foods such as butterfat molecules in milk are split by a specific enzyme in preparation for absorption. Which of the following enzymes is responsible?

lipase Signup and view all the answers

Parietal cells of the stomach produce ________.

hydrochloric acid Signup and view all the answers

Hepatocytes do not ________.

produce digestive enzymes Signup and view all the answers

Which of the following is not a phase of gastric secretion?

enterogastric Signup and view all the answers

Which vitamin requires intrinsic factor in order to be absorbed?

B12 Signup and view all the answers

Chief cells ________.

are found in the basal regions of the gastric glands Signup and view all the answers

Chemical digestion reduces large complex molecules to simpler compounds by the process of ________.

catabolism Signup and view all the answers

The ________ contains lobules with sinusoids (lined with macrophages) that lead to a central venous structure.

liver Signup and view all the answers

If an incision has to be made in the small intestine to remove an obstruction, the first layer of tissue to be cut is the ________.

serosa Signup and view all the answers

The terminal portion of the small intestine is known as the ________.

ileum Signup and view all the answers

The dental formula for an adult is 2-1-2-3. What does the 1 stand for?

canine tooth Signup and view all the answers

Digestion of which of the following would be affected the most if the liver were severely damaged?

lipids Signup and view all the answers

________ is locally regulated in the blood by the active form of vitamin D, which acts as a cofactor.

Calcium Signup and view all the answers

Important peritoneal folds do not include the ________.

round ligament Signup and view all the answers

The lamina propria is composed of ________.

loose connective tissue Signup and view all the answers

________ is (are) not important as a stimulus in the gastric phase of gastric secretion.

Carbohydrates Signup and view all the answers

Pancreatic amylase does not get to the small intestine via the ________.

cystic duct Signup and view all the answers

The function of the goblet cells is to ________.

produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion Signup and view all the answers

Which of the following is an essential role played by large intestine bacteria?

synthesize vitamin K and B-complex vitamins Signup and view all the answers

Nervous control of gastric secretion is provided by ________.

the vagus nerve and enteric plexus Signup and view all the answers

Which of the following are types of papillae on the tongue that contain taste buds?

fungiform and circumvallate Signup and view all the answers

Which of the following produce intrinsic factor?

parietal cells Signup and view all the answers

Which of the following enzymes is specific for proteins?

trypsin Signup and view all the answers

Surgical cutting of the lingual frenulum would occur in which part of the body?

tongue Signup and view all the answers

A fluid secreted into the small intestine during digestion that contains cholesterol, emulsification agents, and phospholipids is ________.

bile Signup and view all the answers

The layer of the digestive tube that contains blood vessels, lymphatic nodes, and a rich supply of elastic fibers is the ________.

submucosa Signup and view all the answers

Which of the following is not characteristic of the large intestine? It ________.

is longer than the small intestine Signup and view all the answers

What stomach secretion is necessary for normal hemoglobin production in RBCs?

intrinsic factor Signup and view all the answers

How are most nutrients absorbed through the mucosa of the intestinal villi?

active transport driven directly or indirectly by metabolic energy Signup and view all the answers

Select the correct statement about the regulation of gastric secretion.

Gastric secretion can be stimulated before food has entered the mouth. Signup and view all the answers

Paneth cells ________.

secrete enzymes that kill bacteria Signup and view all the answers

Select the correct statement about digestive processes.

Chyme entering the duodenum can decrease gastric motility via the enterogastric reflex. Signup and view all the answers

Chemical digestion in the small intestine involves ________.

Signup and view all the answers

Study Notes

Digestive System Overview

Absorption is the process of nutrients passing from the gastrointestinal tract into the blood or lymph.
Mechanical and chemical receptors controlling digestion are located in the walls of the tract organs.

Circulation and Digestion

Hepatic portal circulation collects absorbed nutrients for processing or storage.
Digestion includes both chemical and mechanical breakdown of food.

Digestive Processes

Large molecules like lipids and proteins undergo catabolic reactions known as chemical digestion.
Peristaltic waves are muscular contractions propelling contents through the gastrointestinal tract.

Structure of the Alimentary Canal

The alimentary canal's walls consist of four basic layers: mucosa, submucosa, muscularis externa, and serosa.
Mesenteries are sheets of peritoneal membrane that support digestive tract organs.

Stomach and Gastric Secretion

The stomach initiates protein digestion and denatures proteins.
Hydrochloric acid is secreted by parietal cells; intrinsic factor is vital for B12 absorption.

Enzymatic Actions

Amylase digests carbohydrates; lipase functions on lipids.
Trypsin is a specific enzyme for protein digestion.

Hormones and Enzymes

Cholecystokinin (CCK) stimulates enzyme-rich pancreatic juice and gallbladder contraction to release bile.
Gastrin enhances acid secretion in response to protein presence.

Salivary Glands and Saliva Functions

Salivary glands include serous and mucous cells; saliva contains enzymes, electrolytes, and IgA but does not digest proteins.
Goblet cells in the digestive tract produce mucus that protects against enzymatic digestion.

Nutrient Absorption

The small intestine has increased absorptive effectiveness due to plicae circulares and intestinal villi.
Active transport is the primary mechanism for nutrient absorption across the intestinal mucosa.

Intestinal Functions

The large intestine houses bacteria essential for synthesizing vitamins K and B-complex.
Calcium absorption is co-regulated by vitamin D and primarily occurs in the duodenum.

Dental Anatomy and Salivary Function

The adult dental formula includes 32 teeth; canines are represented by the '1' in the formula.
Certain cells in the digestive system, including Paneth cells, secrete antibacterial enzymes.

Important Digestive Components

Bile emulsifies fats and contains bile salts, cholesterol, and phospholipids; it does not contain digestive enzymes.
The submucosa layer of the digestive tube contains blood vessels and lymphatics.

Clinical Insight

Damage to the liver greatly affects lipid digestion due to compromised bile production.
Surgical interventions in the intestine would first cut through the serosa layer.

Digestive Reflexes and Nutrient Processing

Chyme's arrival in the duodenum decreases gastric motility via the enterogastric reflex.
If proteins pass intact across the villus epithelium, it may trigger an immune response.

Electrolyte and Nutrient Dynamics

Iron and calcium absorption predominantly occur in the duodenum; potassium transport involves active mechanisms.
The pancreas is essential for digesting high-fat meals by releasing bile for emulsification.

These notes cover the critical concepts and details concerning the components and functions of the digestive system.### Alimentary Tube Development

The mucosa of the developing alimentary tube originates from the endoderm.

Projectile Vomiting in Infants

Infants displaying projectile vomiting may suffer from pyloric stenosis, where the pyloric sphincter is thickened and does not open properly.
Loss of gastric juice in these infants can lead to alkalosis.

Hormonal Regulation

Secretin inhibits gastric secretion, playing a crucial regulatory role in digestive processes.

Splanchnic Circulation

The inferior vena cava is not part of the splanchnic circulation, unlike the hepatic portal vein, superior mesenteric artery, and celiac artery.

Components of Saliva

Saliva contains lysozyme and defensins but does not include nitric oxide or a cyanide compound.

Immunity in the Intestine

The IgA antibody-mediated immune response helps prevent pathogens in the large intestine from penetrating the mucosa.

Ascites

Ascites is characterized by abnormal fluid accumulation in the peritoneal cavity, leading to abdominal bloating.
It can result from conditions like portal hypertension, liver cirrhosis, or heart/kidney diseases.

Barrett's Esophagus

Barrett's Esophagus involves a pathological change from stratified squamous to metaplastic columnar epithelium in the lower esophagus.
This condition is associated with chronic gastroesophageal reflux and increases the risk for adenocarcinoma.

Bruxism

Bruxism refers to teeth grinding or clenching during sleep, often due to stress, potentially leading to dental damage.

Bulimia

Bulimia is characterized by binge-purge behavior, stemming from a fear of weight gain, and can lead to severe health issues.

Dysphagia

Dysphagia is identified as difficulty swallowing, which may be due to obstruction or trauma to the esophagus.

Endoscopy

Endoscopy involves the visual examination of the body's interior, used in procedures such as colonoscopy and sigmoidoscopy.

Enteritis

Enteritis is inflammation of the intestines, particularly the small intestine.

Hemochromatosis

Hemochromatosis is an iron metabolism disorder causing excess iron deposition in tissues, contributing to skin pigmentation changes and increased cancer risk.

Ileus

Ileus refers to the cessation of GI tract movement, resulting in a paralyzed gut, often due to electrolyte imbalances or drug effects.

Inflammatory Bowel Disease (IBD)

IBD encompasses recurring inflammation of the intestinal wall, manifesting as symptoms like cramping and diarrhea.
Crohn's disease is more severe, affecting the entire intestinal tract, while ulcerative colitis mainly impacts the large intestine.

Laparoscopy

Laparoscopy allows for examination of the peritoneal cavity via an endoscope, often assessing digestive and reproductive organs.

Orthodontics

Orthodontics is a dental specialty dedicated to the prevention and correction of tooth misalignment.

Pancreatitis

Pancreatitis is serious inflammation of the pancreas, usually due to high blood fat levels, alcohol use, or bile duct obstructions.

Peptic Ulcers

Peptic ulcers refer to both gastric and duodenal ulcers.

Proctology

Proctology is the study and treatment of diseases affecting the colon, rectum, and anus.

Pyloric Stenosis

Pyloric stenosis is the narrowing of the pyloric sphincter, typically identified when infants start solid foods, causing projectile vomiting.

Vagotomy

Vagotomy is a surgical procedure to cut the vagus nerve, aimed at reducing gastric juice secretion in unresponsive peptic ulcer cases.

Xerostomia

Xerostomia refers to extreme dryness of the mouth, potentially caused by blockages or autoimmune conditions affecting salivary glands.

Peristalsis

Peristalsis involves wavelike smooth muscle contractions that transport food through the alimentary canal.

Digestion Processes

Digestion refers to the breakdown of food into absorbable substances.
Hydrolysis is the enzymatic breakdown of food molecules.

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Test your knowledge of the digestive system with these flashcards from Chapter 23. Each card provides essential terms and definitions that will help reinforce your understanding of digestion and nutrient absorption. Ideal for students looking to review key concepts in biology.