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The DIGESTIVE System – Chapter 14 Marieb text
Time to Get this Study Guide DONE! 
* = page number in Marieb textbook
Answer all Q’s on a separate sheet of paper and STUDY for your Quizam!
QUIZAM: Thursday, April 17th-
Overview
1) List the organs of the alimentary canal in order from beginning to end. *412
ORAL CAVITY, PHARYNX,
ESOPHAGUS, STOMACH, SMALL
INTESTINE, LARGE INTESTINE
2) What are the 6 major functions of the gastrointestinal tract? Briefly define each. *424-425
INGESTION – TAKE FOOD INTO ORAL CAVITY
PROPULSION – FOOD MOVED THROUGH GI TRACT
CHEMICAL DIGESTION – BREAK DOWN FOOD WITH
ENZYMES
MECHANICAL DIGESTION – BREAK DOWN FOOD
WITH TEETH AND MUSCLE
ABSORPTION – NUTRIENTS TAKEN INTO
BLOODSTEAM
DEFECATION – WASTES REMOVED
3) Name the 4 tissue layers of the GI tract from and describe the major function of each. *415-417
MUCOSA – PRODUCES MUCUS
SUBMUCOSA – CONTAINS NERVES AND BLOOD
MUSCULARIS EXTERNA – PERISTALSIS
SEROSA – PROTECTION/OUTER LAYER
4) What is peristalsis? *424, 427
INVOLUNTARY CONTRACTION AND RELAXATION OF
SMOOTH MUSCLE OF GI TRACT
Structure and Functions
5) What is the function of the epiglottis during swallowing? *427
FLAP OF CARTILAGE THAT COVERS GLOTTIS
(RESPIRATORY PATHWAY) DURING SWALLOWING
6) Which organ of the digestive system is the longest? Why is this (what process happens here)? *418
SMALL INTESTINE!!! MOST ABSORPTION AND
CHEMICAL DIGESTION HAPPENS HERE
7) Name at least 4 accessory organs of the digestive system and briefly describe their functions. *421-422
PANCREAS – RELEASES PANCRATIC JUICE / ENZYMES
GALLBLADDER – STORES BILE
SALIVARY GLANDS – PRODUCE SALIVA/ENZYMES
LIVER – PRODUCES BILE
8) What is the function of the mucus secreted by glands in the stomach and small intestine? *418
REDUCES FRICTION/ PROTECTS STOMACH AGAINST
HYDROCHLORIC ACID
9) Why does the stomach wall have 3 layers of muscle (instead of 2)? *418, 429
THE THREE LAYERS HELP IN MECHANICAL DIGESTION
OF THE CHYME
10) Food enters the stomach through which valve? *416, 417
CARDIOESOPHAGEAL VALVE
11) What are the three portions of the stomach? Where does most of the chemical digestion happen? *417
FUNDUS, BODY, **PYLORUS
12) Food enters the small intestine through which valve? *416, 417
PYLORIC VALVE
13) What is the first section of the small intestine (where the bile and pancreatic juice enters) called? *418
DUODENUM
14) Food enters the large intestine through which valve? *418, 420
ILEOCECAL VALVE
15) What is the mesentery? *417
MEMBRANE THAT CONNECTS SMALL INTESTINE TO
POSTERIOR ABDOMINAL WELL
16) What are villi (and microvilli), where are they found, and what is their function? *419
VILLI ABSORB NUTRIENTS INTO BLOODSTREAM IN THE
SMALL INTESTINE
17) What is the greater omentum? *418
MEMBRANE THAT HANGS FROM STOMACH OVER THE
INTESTINES (“LACY APRON”)
18) Why is it called the “large” intestine? *419
IT IS LARGER IN DIAMETER
19) What are the major functions of the large intestine? *419-420
ABSORBS WATER (AND VITAMINS), AND ELIMINATES
WASTE
Chemical Digestion
20) What is the difference between mechanical and chemical digestion? Which organ begins both ? *424
MECHANICAL = PHYSICAL BREAKDOWN
CHEMICAL = ENZYMES
BOTH START IN THE ORAL CAVITY!!
21) What is the function of bile? Which organ produces it and which organ stores it? *421
BILE BREAKS DOWN FATS
BILE IS MADE IN LIVER
BILE IS STORED IN GALL BLADDER
22) Name the specific organs and enzymes (mainly amylase, lipase, pepsin) involved in the digestion of: *426
a. Carbohydrates
b. Lipids
c. Proteins
CARBOHYDRATES ARE CHEMICALLY DIGESTED BY
SALIVARY AMYLASE IN THE ORAL CAVITY
LIPIDS ARE CHEMICALLY DIGESTED BY LINGUAL LIPASE
IN THE ORAL CAVITY
PROTEINS ARE CHEMICALLY DIGESTED BY PEPSIN IN
THE STOMACH
23) The stomach produces hydrochloric acid (HCl) – what is its function in digestion? *429
ACTIVATES ENZYMES
24) What is chyme? *418
JUICE IN THE STOMACH (FOOD MIXED WITH ACID)
Disorders and Diseases
25) What is heartburn? What causes this condition? *429
GASTRIC JUICES GO UP THROUGH CARDIOESOPHAGEAL
VALVE AND INTO THE ESOPHAGUS
26) Briefly describe the following conditions: *449 and *428
a. Gastroenteritis
b. Appendicitis
c. Peptic ulcers
GASTROENTERITIS = INFLAMMATION ANYWHERE
ALONG THE GASTROINTESTINAL TRACT
APPENDICITIS = INFLAMMATION OF APPENDIX;
IF RUPTURES WOULD RELEASE BACTERIA INTO
ABDOMINAL CAVITY
PEPTIC ULCERS = GASTRIC JUICES CREATE HOLES IN
MUCOSA OF DIGESTIVE TRACT
*Short Answer “Essay” Review Questions – Page 452
 Answer the following questions, in complete sentences, in the space provided below.
 Three Short Answer Essay Questions: #12, #14, #20,
#12  STOMACH JUICES ARE VERY ACIDIC because of
HCl WHICH ACTIVATES THE ENZYMES. THE MUCOSA
LAYER OF THE STOMACH PRODUCES MUCUS TO
PROTECT ITSELF.
#14  THERE WOULD BE FAT IN FECES WHICH MAY
CAUSE A WHITE STOOL IF THERE WERE NO BILE OR
PANCREATIC JUICE.
THESE SECRETIONS CONTAIN ENZYMES TO BREAK
DOWN LIPIDS/FATS.
#20 
MOST NUTRIENT ABSORPTION HAPPENS IN THE SMALL
INTESTINE! 90% OF NUTRIENTS ARE ABSORBED BY THE
VILLI!
Diagrams
A) Summary Overview Diagram of Digestive System (page 413)
B) ORAL CAVITY (page 414)
C) LAYERS OF G.I. TRACT (page 415)
D) STOMACH
(page 416)
**Remember – NO word bank for these on Quizam!
**PIZZA PATHWAY - Trace the pathway of a piece of pizza through the GI tract.
 Be sure to include all ORGANS and all VALVES. (For now – you can LIST)
 Give the major FUNCTION(S) of each organ in digesting the pizza.