1What are the six major functions of the digestive system?
Ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation.
2What is ingestion?
Taking food into the mouth.
3What is propulsion?
Moving food through the digestive tract.
4What is mechanical digestion?
Physically breaking food into smaller pieces.
5What is chemical digestion?
Breaking large food molecules into smaller molecules using enzymes and other chemicals.
6What is absorption?
Movement of nutrients, water, and electrolytes into the blood or lymph.
7What is defecation?
Elimination of indigestible material as feces.
8What is the correct order of the digestive tract?
Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anal canal, anus.
9What is the function of the upper esophageal sphincter?
Regulates passage from the pharynx into the esophagus.
10What is the function of the lower esophageal sphincter?
Helps prevent stomach contents from refluxing into the esophagus.
11What is the function of the pyloric sphincter?
Controls movement of stomach contents into the duodenum.
12What is the function of the ileocecal valve?
Controls movement from the ileum into the cecum.
13What is the function of the internal anal sphincter?
Involuntarily controls the release of feces.
14What is the function of the external anal sphincter?
Voluntarily controls the release of feces.
15What is the function of the teeth?
They mechanically break food into smaller pieces.
16What is the function of the tongue?
Moves food, mixes it with saliva, and helps form a bolus.
17What enzyme begins carbohydrate digestion?
Salivary amylase.
18What are the three major salivary glands?
Parotid, submandibular, and sublingual glands.
19What is the main function of the stomach?
Stores, mixes, and begins chemical digestion of food.
20What do parietal cells produce?
Hydrochloric acid and intrinsic factor.
21What does hydrochloric acid do in the stomach?
Creates an acidic environment and helps activate pepsin.
22What does intrinsic factor do?
Allows vitamin B12 to be absorbed in the terminal ileum.
23What do chief cells produce?
Pepsinogen.
24What is pepsinogen?
An inactive enzyme precursor that is converted to pepsin.
25What does pepsin digest?
Proteins.
26What do G cells produce?
Gastrin.
27What does gastrin do?
Stimulates gastric secretion and activity.
28What do mucous cells produce?
Mucus that protects the stomach lining.
29What are the three sections of the small intestine?
Duodenum, jejunum, and ileum.
30What is the main function of the duodenum?
Receives chyme, bile, and pancreatic secretions and performs extensive digestion.
31What is the main function of the jejunum?
Absorbs many nutrients.
32What is the main function of the ileum?
Absorbs remaining nutrients, including vitamin B12 with intrinsic factor.
33What is the main function of the small intestine?
Most chemical digestion and nutrient absorption.
34What are villi?
Finger-like projections that increase the small intestine's absorptive surface area.
35What are microvilli?
Tiny projections forming the brush border of intestinal cells.
36What are lacteals?
Lymphatic vessels in intestinal villi that absorb most dietary fats.
37What is the main function of the large intestine?
Absorbs water and electrolytes and forms and stores feces.
38What is the first part of the large intestine?
Cecum.
39What is attached to the cecum?
The appendix.
40What is the final part of the large intestine before the rectum?
Sigmoid colon.
41What does the rectum do?
Stores feces before defecation.
42What does the liver produce?
Bile.
43What does the gallbladder do?
Stores and concentrates bile.
44Does the gallbladder produce bile?
No, the liver produces bile.
45What is the main digestive function of bile?
It emulsifies fats, increasing their surface area for lipase.
47What does the pancreas produce for digestion?
Digestive enzymes and bicarbonate.
48What does pancreatic bicarbonate do?
Helps neutralize acidic chyme entering the duodenum.
49Where does most chemical digestion occur?
In the small intestine.
50Where does most nutrient absorption occur?
In the small intestine.
51Where does carbohydrate digestion begin?
In the mouth.
52Where does protein digestion begin?
In the stomach.
53Where does most fat digestion occur?
In the small intestine.
54What does amylase digest?
Starch and other carbohydrates.
55What does maltase digest?
Maltose into glucose.
56What does sucrase digest?
Sucrose into glucose and fructose.
57What does lactase digest?
Lactose into glucose and galactose.
58What does pepsin digest?
Proteins into smaller peptides.
59What do trypsin and chymotrypsin digest?
Proteins and peptides.
60What do peptidases produce?
Smaller peptides and amino acids.
61What does pancreatic lipase digest?
Triglycerides into mainly monoglycerides and free fatty acids.
62What are the final products of carbohydrate digestion?
Monosaccharides such as glucose, fructose, and galactose.
63What are the main products of protein digestion?
Amino acids and small peptides.
64What are the main products of triglyceride digestion?
Monoglycerides and free fatty acids.
65What is peristalsis?
Wave-like muscular contractions that propel food through the digestive tract.
66What is segmentation?
Contractions that mix intestinal contents and increase contact with the intestinal lining.
67What is the difference between mechanical and chemical digestion?
Mechanical digestion physically breaks food apart; chemical digestion breaks chemical bonds.
68Where are most dietary fats absorbed?
Through intestinal lacteals into the lymphatic system.
69Where are carbohydrates and amino acids mainly absorbed?
Into blood capillaries in the intestinal villi.