Download Review Sheet: The Digestive System

Review Sheet: The Digestive System
1.
2.
Know the diagram of the digestive system.
Explain the difference between mechanical and chemical digestion. Where in the digestive system does
each occur? Mechanical digestion required muscular movement and chemical digestion requires
enzyme.
3. What is homeostasis? The balance of the body’s internal environment; must be within narrow ranges
4. What is ingestion? The taking in of food Where does it occur? mouth
5. What are the 4 steps of digestion? Ingestion, mechanical & chemical digestion, absorption, elimination
6. Describe the process of swallowing. Include the words: teeth, salivary glands, tongue, bolus, pharynx,
epiglottis and esophagus in your description. As you ingest food, your teeth mechanically break down
the food in order to increase the surface area and the salivary glands release saliva which contains
salivary amylase to chemically break down food. Your tongue assists with the movement of food
and the formation of the bolus. As you swallow, your soft palate contracts to cover the nasopharynx
region and the bolus moves through the pharynx. As the bolus passed by the flap of tissue called
the epiglottis, it forces the epiglottis down to cover you trachea thereby allowing the bolus to enter
the esophagus.
7. What are the functions of saliva? Antibacterial action, moisten food and mouth (including taste buds)
and break down starch with the catalyst salivary amylase.
8. How many pairs of salivary glands are there? 3
9. Give the enzymatic reaction (substrate, enzyme and product) that result in the oral cavity. What is the
optimum pH for this enzyme? starch amylase maltose at a pH of 7
10. What is the pharynx? The region between the mouth and the lower tubes. Name the two tubes that are
located there. Trachea and esophagus
11. What is the epiglottis? The flap of tissue that covers the trachea when bolus passed it Name its
function. Covers the trachea the prevent choking
12. What is peristalsis? Wave-like muscular contractions that will push the food through the digestive
tract
13. What is a sphincter? A muscular valve that controls substances from entering or exiting Name the
sphincter that prevents food from going back into the esophagus. Cardiac or esophageal sphincter Name
the sphincter that prevents food from going back into the stomach from the small intestine. Pyloric
sphincter
14. What is gastric juice? The juice secreted from the cells of the stomach Name the 3 substances that are
secreted in the stomach. HCl, muscous, pepsinogen
15. What is the optimum pH of pepsin? 2
16. Why is pepsin secreted as pepsinogen from the stomach wall? Pepsinogen is the inactive form of
pepsin. Pepsin digests protein and therefore would digest the protein in the cell membranes of the
cells that are secreting it and therefore, the stomach cells secrete the inactive form so that only the
proteins in the food are digested and not the cell membrances.
17. What is the function of the mucus layer that lines the stomach? Protects the stomach lining (the cells)
from the acidity of the gastric juices
18. What is the name of the semi liquid mass in the stomach? chyme
19. a) What is the liver? An accessory organ that contributes to digestion
b) Explain the functions of the liver. Produces bile, destroys old RBCs; breaks down hemoglobin;
regulate blood glucose levels; produces urea; produces blood plasma proteins; produces and regulates
cholesterol; stores iron ion and fat soluble vitamins; detoxifies blood
c) Explain 2 disorders associated with the liver. Cirrhosis & jaundice
d) What are gall stones? Crystallization of cholesterol in bile in which the crystals become too large
and block the bile duct.
20. What is the function of the gall bladder? Stores excess bile
21. Name the 2 main functions of the pancreas. Produces pancreatic juices & secretes insulin & glucagon
22. Explain the function of insulin and glucagon. Insulin is secrete if blood glucose levels are too high and
therefore, “encourage” liver cells to take up glucose. Glucagon is secrete if blood glucose levels are
too low and therefore, communicates with liver to release glucose into blood (glycogen, a polymer,
breaks down into glucose, the monomer)
23. What is the duodenum? The first portion of the small intestine.
24. What is bile? Substance secreted by liver, stored in gall bladder that acts in the small intestine to
emulsify fat into fat droplets (smaller fats to increase surface area of fat) Why is it not considered to be
an enzyme? Does not chemically break down fat, just physically whereas enzymes assist with
chemical reactions. What is meant by emulsification? The breaking down of fat into fat droplets.
25. What is pancreatic juice? The mixture (juice) that is directly secreted from the cells of the pancreas.
This juice is produces in the pancreas but acts in the small intestine
26. What is intestinal juice? The mixture (juice) that is directly secreted from the cells of the small
intestine
27. Give the enzymatic reactions that occur in the small intestine. All those enzymes in the intestinal juice
and the pancreatic juice. See you notes What is the optimum pH for these enzymes? Slightly basic
(about 8 to 9)
28. How is stomach acid buffered in the small intestine? By sodium bicarbonate that is released as from the
pancreas and travels via the pancreatic duct
29. What is absorption? The ability of the small intestine to move the nutrients from the digestive system
into the blood and lymph system (lacteal) How is the small intestine specialized for absorption? By
significantly increasing the surface area (the villi and microvilli) What is absorbed here?
Monosaccharides (glucose) and aa into the blood capillaries and glycerol and fatty acids into the
lacteal.
30. Explain how surface area is increased in the digestive system. Convoluted lining of the system (ie fold in
stomach and villi/microvilli in the intestinal walls)
31. Draw a villus and explain the function of its parts.
32. Describe the role of E. coli in the colon. Further breaks down material that has not been digested thus
far
33. Contrast endocrine and exocrine glands. Endocrine secretes hormones into the blood stream and
exocrine secrete products into ducts for transport Give an example from the digestive system.
Pancreas does both via the pancreatic duct and directly secretes insulin and glucagon into the
blood stream
34. What is absorbed in the colon? Water and salts
35. Explain two problems that can be associated with elimination. Diarrhea (failure to absorb water) and
constipation (too much water is absorbed)
36. Explain the complete digestion of carbohydrates, proteins, nucleic acids and fats as they pass through the
digestive system.
Don’t need to know the names of
these, just consider it trypsin
37. Which of the following is considered an accessory organ in the digestive system?
a) pharynx b) esophagus c) stomach d) pancreas
38. In the body, glucose is stored in the liver as
a) starch b) protein c) glycogen d) glucagons e) amino acids
39. Liver does NOT function in the production of
a) bile b) digestive enzymes c) blood proteins d) glycogen
40. The hepatic portal vein is located between
a) the hepatic vein and the vena cava b) the mouth and the stomach c) the pancreas and the small intestine
d) the small intestine and the liver
41. What is the role of HCl in the stomach?
a) symptom of a digestive disorder b) only to cause stomach ulcers c) digestive enzymes to hydrolyze fats
d)aids in the digestion of starch e)activates a digestive enzyme, pepsin
42. Name the structure and organ that has microvilli, maltase, and absorbs nutrients.
a) villus, large intestine b) villus, small intestine c) villus, stomach d) folds, stomach e) pyloric sphincter,
appendix
43. In mammals, fats are absorbed
a) in the large intestine b) in the stomach c) into the blood capillaries d) into the lacteal e) none of the
above are correct
44. At body temperature, which of these combinations is most likely to result in digestion?
a) protein, water, pepsin b) protein, HCl, pepsin c) protein, bile, pepsin d) protein, sodium bicarbonate,
pepsin
45. At body temperature, which of these combinations is most likely to result in digestion?
a) fat, bile, sodium bicarbonate, lipase
b) fat, bile, sodium bicarbonate, pepsin c) fat, HCl, maltase d)fat,
bile, HCl, sodium bicarbonate, trypsin
46. Which of the following human digestive enzymes is incorrectly matched to its substrate?
a) pepsin – protein b) trypsin- nucleic acid c) salivary amylase – starch d) lipase – fat e)maltase-maltose
47. Which organ in the human body produces maltase and peptidases?
a) mouth b) esophagus c) stomach d) small intestine e) large intestine
Use the following information to answer the next 4 questions
a) protein pepsin peptides
b) starch amylase maltose
c) maltose maltase glucose
d) fat
lipase fatty acids + glycerol
48. Which reaction above is aided by a pH of about 2- 3?
a) a b) b c) c d) d e) none
49. Which reaction above occurs in both the mouth and duodenum
a) a and c b) a
c) d d) c and d e) b
50. In the reactions above, in order for reaction “d” to proceed efficiently
a) the pH must be at least 2 b) pancreatic juice must be secreted c) bile must be present d) HCl must be
present e) pancreatic juice must be secreted and bile must be present
51. In the reactions above, reaction “a” occurs in the
a) stomach b) oral cavity c) large intestine d) small intestine e) esophagus
52. Protein digestion is confined to the
a) mouth, stomach, small intestine
b) stomach, small intestine c) stomach, esophagus, small intestine
d)mouth, large intestine e) small intestine, large intestine, mouth
53. The fingerlike projections along the surface on the small intestine are called
a) mucosa b) lacteals c) capillaries d) villi e) appendix
54. Microvilli form a brush border on the cells of the
a) esophagus b) stomach c) duodenum d) tongue e) pharynx
55. Which of these organs has food for the least time and participates least in digestion?
a) mouth b) esophagus c) stomach d) small intestine e) large intestine
56. The main function of the esophagus is to
a) digest proteins b) digest carbohydrates c) transport food from the small intestine to the large intestine
d)transport food from the mouth to the stomach e) transport food from the stomach to the large intestine
57. A correct function of the human stomach is
a) to produce highly basic fluids to kill most bacteria
b) to begin the absorption of most small food molecules, especially sugars and alcohol
c) storage of food and mixing with digestive fluids to begin chemical digestion
d) promotion of bacterial fermentation
e) absorption of iron to build hemoglobin for red blood cells
58. The ___ functions to store food, kill bacteria, and partially digest protein
a) mouth b) esophagus c) stomach d) small intestine
e) large intestine
59. Food and liquid is prevented from entering the trachea by the
a) pharynx b) larynx c) epiglottis d) glottis e) sphincter muscle
Use the following diagram to answer the next 6 questions.
60. Which structure above stores food, has limited digestion, and secretes HCl?
x
61. In the diagram, which structure is the primary site for digestion and absorption of food?
v
62. In the diagram, the esophagus is designated by the number
t
63. Into which structure does food pass but no digestion takes place?
t+z
64. In the diagram, the food material that is absorbed will first enter which organ?
u
65. In the diagram which structure is the liver?
u
66. The digestive system functions in the
a) chemical breakdown of food b) mechanical breakdown of food c) elimination of waste products
d) absorption of food molecules e) all of the above
67. Which of the following is NOT a function of the digestive system?
a) ingestion of food b) digestion of food c) absorption of food d) elimination of digestible wastes
e)elimination of non digestible wastes
68. Muscles that encircle tubes and act a valves are called
a) constrictors b) dilators c) sphincters d) lacteals e) mucosa
69. The duodenum is the site for
a) a duct from the liver that introduces bile b) a pancreatic duct that introduces basic fluids to neutralize the
stomach acid c) highly acidic stomach contents d) all of the above
70. Water is absorbed primarily by the
a) colon b) duodenum c) anal canal d) esophagus
71. Fat absorption differs from other foods because its breakdown products are
a) formed in the large intestine b) absorbed directly into the blood c) absorbed into the lacteal
d)absorbed only when glucose is not present
72. Villi serve to
a) absorb nutrients b) secrete bile c) produce antibodies d) synthesize vitamins
Match the words/description on the right with the terms on the left. There may be several answers for each
term.
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Bolus _______N, O, P___________
Epiglottis_________Q______________
Esophagus ______A, N_____________
Sphincter relaxed _____M___________
Sphincter contracted ____L_________
Stomach __C, D, E, F, I, J, K__
Mechanical digestion ______G, I _____
Peristalsis______N______
Gastric glands ___C, D, E, F___
Duodenum ______B________
Small Intestine_____B, H ________
Villi _________B__________
Intestinal villi cells __________B_______
A. extends from pharynx to the stomach
B. increased surface area
C. gastric pits
D. chyme
E. pepsin, HCl, and mucus
F gastric juice
G. chewing
H ~ 3 m long
I churning
J stores food
K continuous with esophagus and duodenum
L closed
M open
N swallowing
O mixed with saliva
P tongue
Q flap of tissue to cover trachea