Digestion & Absorption Flashcards
1
Q
What is the alimentary tract?
A
digestive tract
2
Q
What is bolus?
A
what food turns into following chewing
3
Q
What enzymes help break down food?
A
amylase (protein) and lipase (fat) pepsin (protein)
4
Q
What cells are present in the stomach to help break down?
A
chief cells, parietal cells, mucous cells, G cells
5
Q
What is the purpose of chief cells?
A
-Secretes lipase which breaks down fats.
-Releases pepsinogen
6
Q
What is the purpose of parietal cells?
A
-Secretes intrinsic factor
-Releases HCL, which is needed to convert pepsinogen to pepsin (to then breakdown proteins)
7
Q
What is the purpose of intrinsic factor?
A
Needed for the absorption of B12 and HCL
8
Q
What is the purpose of mucous cells?
A
-release mucus to protect stomach lining
-lubricates
-protect stomach lining
9
Q
What is the purpose of gastrin?
A
Signals the release of HCL
10
Q
What part of the small intestine is the primary part for nutrient absorption?
A
jejum and ileum
11
Q
What is the last stop for food in the small intestine?
A
duodenum
12
Q
What stimulates the release of secretin?
A
duodenum
13
Q
When fat and protein enter the duodenum what is stimulated?
A
cholecystokinin
14
Q
The presence of cholecystokinin in the duodudeum causes what?
A
It triggers the gallbladder and pancreas to contract, which then causes bile to be released. This way bile can combine with the food to turn into absorbable nutrients.
15
Q
What is required for trypsin activation?
A
enterokinase
16
Q
What are extozymes produced by?
A
enterocytes
17
Q
What is the purpose of pancreatic bicarbonate?
A
Can decrease HCL into a weaker acid
18
Q
Bile is stored in____and released by____
A
-stored in gallbladder
-released by liver
19
Q
What water process is used to move nutrients through digestion?
A
osmosis
20
Q
What is passive diffusion?
A
high concentration to low concentration
21
Q
What uses passive diffusion?
A
lipids
22
Q
What is facilitated diffusion?
A
has a protein attached to transport
23
Q
What uses facilitated diffusion?
A
carbohydrates
24
Q
What is active transport?
A
low concentration to high concentration
25
What uses active transport?
proteins
26
What is the purpose of the intestinal barrier?
not allow any foreign or bad organisms into the gastrointestinal areas or the portal vein
27
What is the purpose of GALT?
first line of defense against foreign cells. It releases SIgA to support in this process.
28
What test is used to determine status of mucosal barrier?
lactulose test
29
What is glutathione?
-an intestinal anti-oxidant
-can help breakdown foreign products in digestion
-does not need B12 to do this
30
What fuels enterocytes?
glutamine
31
What happened in glutamine levels are low?
-cell death
-decrease in digestion ability
32
What is the role of the large intestine?
-reabsorb water
-fermentation of dietary fiber
33
What is the purpose in the fermentation of dietary fibers in the large intestine?
-dietary fiber is used as the primary energy source for coloncytes
-
34
What are examples of soluble dietary fiber?
-beta-glucans
-ex: pectins, gums
35
How much dietary fiber do we need daily?
25-35 g
36
What are non fermentable fibers?
oats
37
What does the nervous system release to support the digestive process?
actetylcholine
38
What is the most common form of carbohydrate malabsorption?
lactose intolerance
39
What is the common form of protein malabsorption?
celiacs disease
40
What protein are individuals intolerant of if they have celiacs disease?
gliadin
41
What is the protein factor gliadin found in?
-wheat
-rye
-barley
42
What diet does and individual with celiacs disease follow?
gluten free
43
Fat malabsorption shows the following symptom?
steatorrhea
44
What is GERD?
burning sensation or acid reflux
45
What condition is connected to GERD?
obesity
46
What causes secretory diarrhea?
-vital infections
-drugs
47
What causes osmotic diarrhea?
-alcohol
-lactose intolerence
48
What areas are affected by Crohn's disease?
any part of the digestive tract
49
What areas are affected by ulcerative colitis?
the colon
50
Cohn's disease can lead to malabsorption of this major nutrient?
fat and fat soluble vitamins
51
Increase in this type of acids has shown to cause IBD?
linoleic acid
52
What is necessary for antimicrobial defense?
secretion of GALT and SIgA
53
If the intestinal barrier is harmed what needs to be supported?
GALT
54
What is the major intestinal antioxidant?
glutathione (GSH)
55
What is the fuel source for enterocytes?
glutamine
56
Gherlin stimulates?
hunger
57
What do chief cells release?
lipase and pepsinogen
58
What does pepsin break down?
proteins
59
What do parietal cells release?
-intrinsic factor
-HCL
60
What does in the intrinsic factor support?
B12 absorption
61
What is stimulated when fat and protein enter the large intestine?
CCK or cholecystokinin
62
What does CCK stimulate the release of?
bile from the gallbladder
63
What does bile mix with to break down nutrients and aid in absorption?
pancreatic enzymes
64
What are ectoenzymes responsible for?
-final breakdown in digestion
-located in small intestine
-break carbs into glucose and fructose
-proteins into amino acids
65
What does amylase break down?
carbs
66
What does lipase break down?
fats
67
What do chief cells release to break down fats?
lipase
68
Besides lipase, what do chief cells release and synthesize?
pepsinogen
69
What is pepsin (active form of pepsinogen) needed for?
break down of proteins
70
What do parietal cells release?
intrinsic factor
71
What is intrinsic factor needed for?
b12 absorption
72
Besides intrinsic factor, what do parietal cells release?
HCL or hydrochloric acid
73
What is HCL needed for?
-protein absorption
-kills pathogens in food
-activates pepsinogen to pepsin for break down of fats
-activates gastric intrinsic factor
74
What converts pepsinogen to pepsin?
HCL
75
Does the release of HCL decrease in increase stomach PH?
it decreases stomach PH
76
Does pepsin formation need high stomach ph or low?
low
77
What do G cells release?
gastrin
78
What does gastrin stimulate the release of?
gastin, when then stimulates the release of HCL
79
What happens to food in the duodenum?
food break down
80
What happens in the jejunum and ileum?
nutrient absorption
81
The cells on the microvilli that are responsible for nutrient absorption are?
enterocytes
82
What do enterocytes have?
microvilli
83
What is the common bile shunt?
A shunt that carries bile from the liver-->gallbladder-->pancreas-->duodenum
84
What stimulates bile release?
the presence of protein, fat and CCK
85
What hormone stimulates bile release?
CCK or cholesctokinin
86
What is the purpose of enterokinase in digestion?
-an enzyme that activates trypsinogen, which is needed to digest proteins.
87
What does enterokinase activate in the small intestine?
trypsinogen aka makes it into trypsin
88
Why do we need tyrpsinogen converted to trypsin?
to break down proteins in small intestine
89
What is a mutations of enterokianse called?
is called enteropeptidase or congenital enteropeptidase deficiency
90
What diseases are related to damaged microvilli?
celiac disease, tropical sprue, short bowel syndrome, IBD
91
What is the purpose of ectoenzymes in digestion?
help with the final break down of carbs, protein and fats.
92
Where is bile created and stored?
bile is created in the liver and stored in the gallbladder .
93
What is bile up of?
Colic acid
Chenodeoxycholic acid
Taurine
Glycine
Cholesterol
Electrolytes
Wate
94
What do bile salts covert fatty acids to?
water soluble fatty acids. Now they can be absorbed through the lymphatic fluid and head to the liver.
95
What do fermented starches do?
Feed colonocytes and good bacteria
Help heal digestive lining
Boots immune system
Keeps cholesterol levels healthy
96
Describe soluble fiber?
Beta glucans
Need 25-35 g daily
Mixes with water
Slows down food
Lowers blood sugar and cholesterol
97
Describe insoluble fiber?
Cellulose
Fiber that won't mix with water
Found on skin of fruit
98
What type of fiber is psyllium?
non-fermentable
99
What do fermented dietary fibers turn into?
short chain fatty acids (mostly butyrate)
100
What are the 3 ways nutrients are absorbed?
passive, facilitated and active transport
101
Describe passive, facilitated and active transport:
passive: high to low, used by fats
facilitated: high to low, with lipid soluble protein carrier, used by carbs
active: low to high, used by proteins
102
How to maintain a healthy small intestine and tight junctions?
Healthy microbiota
Secretory IgA
It can bind to pathogens in the gut, which then neutralizes them.
Prevents excessive inflammation
GALT
Stands for gut associated lymphoid tissue, which is the collection of lymphoid tissues and immune cells located in the GI tract.
Need to support overall immune system
Protect against harmful pathogens
Peristaltic movement
The speed at which food flows
Filtration of enterocytes
Healthy mucosal lining
103
What is the purpose of secretory of IgA?
-It can bind to pathogens in the gut, which then neutralizes them
-prevents inflammation
104
What is GALT? What is its function?
-Stands for gut associated lymphoid tissue, which is the collection of lymphoid tissues and immune cells located in the GI tract.
-Need to support overall immune system
-Protect against harmful pathogens
-helps food move
-filtration of enterocytes
-supports healthy mucosal lining
105
Define peristaltic movement?
the speed which food flows
106
What compromises tight junctions?
-consuming foods we are allergic to
-high stress
-E. coli exposure
-h. pylori
-low bacterial diversity
-antibiotics use
107
what is h. pylori?
type of bacteria that can colonize the stomach lining and cause go disorders
108
What two nutrients are needed to maintain healthy barrier function in the GI?
Glutathione and glutamine
109
What is glutathione?
-intestinal antioxidant
-reacts with free radicals to convert them to less harmful compounds and protect from oxidative stress
-made in the liver
-needs glutamine, glycine and cysteine to make glutathione
110
Define a free radical.
unstable and high reactive molecules in the body. They have an unpaired election, which makes them eager to bind to the other molecules then become stable. They want to steal from others, which is why they are a problem.
111
Define oxidative stress.
imbalance between harmful molecules aka free radicles and protective molecules aka antioxidants. when there are too many free radicals and not enough antioxidants, it leads to oxidative stress.
112
What is glutamine?
-a type of amino acid
-fuel source or food for enterocytes
-heals the intestinal permeability
-one of the components to make glutathione
-keeps microvilli healthy
113
What nutrients are absorbed in the stomach?
-water
-alcohol
-Copper
-B12
114
What nutrients are absorbed in the duodenum?
-calcium
-folate
-MG
-iron
-A
-D
115
What nutrients are absorbed in the jejunum?
-sugars
-lactose
-proteins
-fat
116
What is absorbed in the stomach?
ethanol and water
117
What are the functions of the large intestine?
-final part of digestion
-absorbs water, electrolytes and vitamins
-plays a crucial role in creation of short chain fatty acids
118
what are the 3 main short chain fatty acids?
acetate, propionate and butyrate
119
Role of short chain fatty acids?
-intestinal integrity and immune health-->promote production of mucin
-supplying energy to enterocytes in the late intestine-->specifically butyrate
-anti-inflammatory agents
-glucose homeostasis
-obesity regulation
-gene regulation
120
How do short chain fatty acids support insulin?
SCFAS improve insulin sensitivity and regulating blood sugar levels.
121
How do short chain fatty acids regulate obesity?
short chain fatty acids can influence the release of hormones that regulate appetite (this decreases the desire to eat)
122
What cells on the microvilli are responsible for nutrient absorption?
enterocytes
123
What inactive pancreatic enzymes are released with CCK?
zymogens
124
How do zymogens become active?
When enterokinase activates typisinogen into trypsin
125
What is a mutation in enterokinase called?
enteropeptidase
126
What are ectoenzymes?
involved in digestion. These enzymes are involved in the final breakdown of carbs, proteins and fats.
127
Starches are broken down by?
gut bacteria through fermentation
128
What are the by products of fermentation?
short chain fatty acids, specifically acetate, propionate and butyrate.
129
Passive absorption is?
-high to low
-fat uses this
130
Facilitated diffusion is?
-high to low, but attached to lipid soluble protein carrier
-carbs uses this
131
Active transport is?
-low to high
-amino acids/proteins use this
132
What is absorbed in the ileum?
b12 and bile salts
133
What is absorbed in the colon?
-potassium
-water
-salt
134
What is the function of the large intestine?
-final part of digestion
-absorb water, electrolytes and vitamins
-fermentation of undigested carbohydrates to produce short chain fatty acids.
135
What are the 3 main short chain fatty acids?
acetate, propionate and butyrate
136
What is the role of short chain fatty acids?
-Intestinal integrity and immune health→promote --production of mucin
-Supplying energy to enterocytes in the large intestine→specifically butyrate
-Anti-inflammatory agents
-Glucose homeostasis
137
How are SCFAS connected to glucose homeostasis?
SCFAS improve insulin sensitivity and regulating blood sugar levels
138
What hormones does the pituitary secrete (8 total)?
1. oxytocin
2. ADH
3. Growth hormone
4. Thyroid stimulating
5. Adrenocorticotropic
6. Prolactin
7. Follicle stimulating
