Ch.23 digestive tract for FOURTH exam Flashcards
(124 cards)
1
Q
_______ is the catabolic process that breaks macromolecules down into monomers small enough for absorption
A
Digestion
2
Q
What type of process is digestion?
A
Catabolic
3
Q
True or false, digestion is a catabolic process that binds monomers into bigger macromolecules
A
False, digestion breaks macromolecules down into monomers
4
Q
Absorption is the process of moving substances from the ____ of the gut into the body
A
lumen
5
Q
What ensures molecules will pass through epithelial cells rather than between them?
A
Tight junctions
6
Q
T or F, gap junctions ensure that molecules will pass through epithelial cells rather than between them?
A
False; tight junctions
7
Q
True or false, lipid molecules must be absorbed through the membrane by active transport
A
False; they can be passed through passively
8
Q
____ molecules can be absorbed passively through the membrane, but other molecules are absorbed by active transport
A
Lipid
9
Q
For the digestion of carbohydrates, only _______ can be absorbed
A
monosaccharide’s
10
Q
For the digestion of carbohydrates, ______ and ______ are broken down into oligosaccharides and disaccharides
A
Starch and disaccharides
11
Q
T or F, maltose can be absorbed
A
False, maltose is not a monosaccharide so it cannot be absorbed through digestion.
12
Q
People with lactose intolerance have deficient amounts of ______ and cannot consume lactose
A
lactase
13
Q
Why do lactose intolerant people get diarrhea when they consume milk?
A
Lactose remains undigested (due to lack of lactase) and creates an osmotic gradient in the intestine that prevents water from being absorbed
14
Q
T or F, any lactose eaten in a person who is lactose intolerant will remain undigested and create a concentrated gradient.
A
False, creates an osmotic gradient
15
Q
What causes bloating, flatulence, and cramping pain?
A
The bacterial metabolism of undigested solutes
16
Q
Sources of protein are not only dietary but they also include….
A
Include digestive enzymes and proteins from the breakdown of mucosal cells
17
Q
Digestion begins in stomach when ______ is converted to pepsin at a pH range of what?
A
pepsinogen; 1.5-2.5
18
Q
How long is the small intestine? from what to what end?
A
2-3M long from pyloric sphincter to ileocecal valve.
19
Q
The small intestine’s length provides what?
A
Provides a huge surface area for nutrient absorption
20
Q
What do the circular folds of the small intestine do?
A
They force chyme to ….
21
Q
______ is the fingerlike projections of mucosa with a core that contains a dense capillary bed and lymphatic capillary called a lacteal for absorption
A
Villi
22
Q
The _______ are cytoplasmic extensions of mucosal cells that give the fuzzy appearance called the brush border that contains brush border enzymes
A
Microvilli
23
Q
What are brush border enzymes used for?
A
Used for final carbohydrate and protein absorption
24
Q
How much intestinal juice is secreted daily?
A
1-2L
25
Major stimulus for production of intestinal juice is _____ or _____ chyme
hypertonic or acidic
26
_____ ______ consists mostly of water but also contains music. Mucus is secreted by duodenal glands and goblet cells of mucosa
Intestinal juice
27
_____ from the stomach contains partially digested carbohydrates and proteins, and undigested fats
Chyme
28
Mucus of intestinal juice is secreted by _______ glands and ______ cells of the mucosa
Duodenal glands; goblet cells
29
What substances are imported from the liver and pancreas into the small intestine?
Bile, bicarbonate, and digestive enzymes
30
Which enzyme performs the final digestion of chyme?
The brush border enzyme that is bound to the plasma membrane
31
Chyme entering the duodenum is usually hyper or hypotonic?
Hypertonic
32
______ delivery has to be slow to prevent the osmotic loss of water from blood
Chyme
33
With regulating chyme entry, what needs to happen to the pH
It needs to be adjusted upward
34
_________ is the most common motion of the small intestine
Segmentation
35
T or F, peristalsis is the most common motion of the small intestine
False...segmentation
36
With digestion of the Small intestine, _______ increases, initiated by rise in the hormone motilin in the late intestinal phase
peristalsis
37
The _________ sphincter controls entry of bile and pancreatic juice into the duodenum
hepatopancreatic
38
Which smaller duct empties directly into the duodenum?
Accessory pancreatic duct
39
Bile and pancreatic juice secretions are both
| stimulated by _____ and ______ controls
hormonal and neural
40
When considering the regulation of bile and pancreatic secretions, hormonal controls include ______ (CCK) and ______
Cholecystokinin and secretin
41
Is bile secretion increased when enterohepatic circulation returns large amounts of bile salts?
Yes
42
What is the major organ of digestion and absorption?
Small intestine
43
Describe the circular folds of the small intestine (They are considered a modification)
Permanent folds that are around 1cm deep that force chime to slowly spiral through lumen, allowing more time for nutrient absorption
44
What are the three major modifications of the small intestine?
Circular fold, villi, and microvilli
45
The ____ of the small intestine are fingerlike projections of mucosa (1mm high) with a core that contains dense capillary beds and a lymphatic capillary called a ______ for absorption
Villi and lacteal
46
True or false, the large intestine is the major organ of digestion and absorption
False; small intestine
47
Which are smaller, villi or microvilli?
Microvilli
48
True or false, microvilli contain lymphatic capillary beds called lacteals
False; villi contain the lacteals
49
______ are cytoplasmic extensions of mucosal cells that give a fuzzy appearance called the brush border that contain membrane bound enzymes
Microvilli
50
_____ _____ enzymes are membrane bound and used for the final carbohydrate and protein digestion
Brush border enzymes
51
How much intestinal juice is secreted daily in response to distension or irritation of mucosa?
1-2L
52
What is the major stimulus for intestinal juice production?
Hypertonic or acidic chyme
53
Is intestinal juice slightly acidic and isotonic with blood plasma?
Yes, but it is alkaline, not acidic.
54
Intestinal juice consists largely of water, but also contains _____
mucus
55
Mucus of intestinal juice is secreted by the duodenal glands and _____ cells of mucosa
Goblet
56
Chyme from the stomach contains partially digested carbohydrates and proteins, and undigested _____
fats
57
How long does it take for the small intestine to absorb all nutrients and most water?
3-6 hours
58
True or false, chyme from the stomach contains partially digested carbohydrates and proteins, and undigested fats
True
59
For digestion, substances such as ____, ____, and digestive enzymes (not brush border) are imported from the liver and pancreas
bile and bicarbonate
60
T or F, chyme entering the duodenum is usually hypertonic; therefore, chyme delivery has to be fast to prevent osmotic loss of water from blood
False...chyme delivery has to be slow, not fast
61
What does chyme need to be mixed with to continue digestion?
Bile and pancreatic juice
62
Does the pH of chyme need to be adjusted higher or lower?
Higher...it's too acidid
63
Between meals, peristalsis increases, initiated by rise in the hormone _____ in the late intestinal phase
motilin
64
Every 90-120 minutes, which hormone increases peristalsis?
Motilin
65
What is moved to the large intestine?
Meal remnants, bacteria, and debris
66
What are the three unique features seen in the large intestine and not anywhere else?
Teniae coli, bacterial flora, and Haustra
67
What is teniae coli of the large intestine?
Three bands of longitudinal smooth muscle in the muscularis
68
The large intestine contains a thicker mucosa made up of _____ _____ epithelium (except for in the anal canal)
simple columnar
69
How many different types of bacterial flora do we have in the LI?
1,000+
70
What outnumbers our cells 10 to 1?
Bacterial flora
71
Bacterial flora enters either the _____ ____ or ___ to colonize the colon
small intestine or anus
72
Where will you find stratified squamous epithelium in the lower GI tract instead of simple columnar epithelium?
In the anal canal
73
Which vitamins do bacterial flora synthesize so the liver can use them to produce clotting factors?
B complex and K
74
T or F, beneficial bacteria outnumbers and suppresses pathogenic bacteria
T
75
Does the immune system destroy any bacteria that tries to breach the mucosal barrier?
Yes
76
Why is the anal canal made up of stratified squamous epithelium instead of simple columnar?
To withstand abrasion
77
What are haustra of the large intestine?
Pocketlike sacs caused by tone of teniae coli
78
Unlike the small intestine, the large intestine does not contain which three details?
Circular folds, villi, or digestive secretions
79
Does the large intestine contain an abundant amount of deep crypts that contain many mucus producing goblet cells?
Yes
80
Which part of the large intestine synthesizes B complex and some vitamin K
Bacterial flora
81
What are the two metabolic functions of bacterial flora?
1. ferments indigestible carbohydrates and mucin
| 2. release irritating acids and gases (500ml/day)
82
Mounting evidence supports findings that the kinds and proportions of gut bacteria can influence what?
Body weight, susceptibility to various diseases, and our moods
83
Evidence supports that bacterial flora can influence our susceptibility to various disease. This includes which three diseases
Diabetes, atherosclerosis, and fatty liver disease
84
T or F, the large intestine contains a thicker mucosa made up of stratified columnar epithelium
False...simple columnar
85
"ferments indigestible carbohydrates and mucin" this describes a function of..
bacterial flora
86
True or false, gut bacteria can influence our moods
True
87
How many deaths occur each year due to antibiotic associated diarrhea?
14k
88
What is the full name for C. diff?
Clostridium difficile
89
What is C. diff?
An anaerobic bacterium that many people carry in the intestine
90
What is a new treatment for patients who suffer from C. diff infections?
Fecal transplants to help replace the missing healthy bacteria which suppresses C. Diff
91
How long does residue remain in the large intestine?
12-24 hours
92
What is the major function of the large intestine?
Propulsion of feces to anus and then defecation
93
True or false, food breakdown occurs in the large intestine
False
94
Vitamins, water, and _____ are reclaimed in the large intestine
electrolytes
95
____ occurs when the large intestine does not have sufficient time to absorb water
diarrhea
96
Prolonged diarrhea may result in what?
Dehydration and electrolyte imbalance
97
______ can occur when food remains in colon for an extended period of time and too much water is absorbed.
Constipation
98
Constipation may result from insufficient amount of ____ or fluid in the diet, improper bowel habits, lack of exercise, or laxative abuse
fiber
99
Material enters the cell through the _____ membrane (lumen side) and exits through the ______ membrane (blood side)
Apical and basolateral (tip for remembering: BB=Basolateral/Blood side)
100
For digestion, Enzymes carry out ______ whereby water is ADDED to break chemical bonds
Hydrolysis (hydro=water)
101
______ and _____ gland enzymes are involved in digestion
intrinsic and accessory
102
The digestion of carbohydrates begins in the _____ with amylase found in the ______
mouth; saliva
103
What are the three main monosaccharide's
Glucose, fructose, and galactose
104
People with lactose intolerance have deficient amounts of ______
lactase
105
Who are abnormal ones, people who are lactose intolerant or people who can drink milk?
People who can drink milk. They have a mutation that allows their body to keep producing lactase even in adulthood.
106
lactose intolerant people who drink milk will have _____
diarrhea
107
What happens when lactose intolerant people drink milk?
Any lactose remains undigested(due to lack of lactase) and this creates an osmotic gradient in the intestine that prevents water from being absorbed.
108
In rare cases, intact proteins are taken up by intestinal epithelial cells by endocytosis and are released into the body. Which age group does this most commonly happen to? Why?
Most common in newborn infants because of the immaturity of their intestinal mucosa
109
Digestion in the stomach begins when _______ is converted to _______ at pH range of 1.5-2.5
Pepsinogen into pepsin
110
Describe what proteins are broken into
Proteins are broken into large polypeptides, small polypeptides and small peptides, and then finally into amino acid monomers with some dipeptides and tripeptides
111
When does pepsin become inactive?
In the high pH of duodenum
112
The _____ of ingested cells in food contain DNA and RNA
nuclei
113
_____ ______ hydrolyze nucleic acid to nucleotide monomers
pancreatic nucleases
114
which three enzymes break down nucleotides into free nitrogenous bases, pentose sugars, and phosphate ions?
Brush border enzymes, nucleosiyeases, and phosphatases
115
Vitamin absorption occurs mostly in which organ?
Small intestine
116
which vitamins are fat soluble?
A, D, E, and K
117
Which vitamins are water soluble?
C and B
118
Which vitamin is a large, charged molecule that binds with intrinsic factor and is absorbed by endocytosis?
B12
119
Which group of vitamins are carried by micelles and diffuse into absorptive cells?
Fat soluble vitamins
120
Which group of vitamins are absorbed by diffusion or by passive and active transporters?
water soluble
121
In the large intestine, which vitamins are absorbed from bacterial metabolism?
K and B
122
_______ can be caused by anything that interferes with delivery of bile or pancreatic juice
Malabsorption
123
What is celiac disease?
A common malabsorption disease:
| immune reaction to gluten, gluten causes immune cell damage to intestinal villi and brush border
124
Treatment for celiac disease
eliminate gluten from diet
