GI System Flashcards
(155 cards)
1
Q
What is the alimentary canal?
A
From the mouth to anus
2
Q
What is the function of the GI system?
A
1) ingestion of food 2) movement of food 3) mechanicals chemical digestion’s 4) absorption of nutrients 5) defecation
3
Q
What are the layers of the intestines? -
A
1) mucosa
2) submucosa-areolar
3) muscularis external 4) serosa
4
Q
What is the function of the mucosal layer?
A
- lines lumen from mouth to anus - secretes mucus, enzymes,+
hormones
_ absorbs nutrients - protects from pathogens
5
Q
Describe the epithelium layer of the intestines
A
Simple columnar from stomach to anus
- Oral cavity & esophagus is non-keratinized stratified squamous
6
Q
What are the three parts to the mucosal layer of the intestines?
A
Epithelium, lamina propria, & muscular is mucosa
7
Q
Describe the lamina propria
A
Areolar CT
8
Q
Describe the muscularis mucosa
A
Smooth muscle- increases surface area & causes minute movement of intestinal functions
9
Q
Describe the submucosa-Areolar CT layer
A
CT w/ vessels & nerves
10
Q
Describe the muscularis external layer
A
2 layers of smooth muscles
- Circular layer & longitudinal
- Helps move food along the tract
11
Q
Describe the serosa layer of the intestines
A
Outermost layer (simple squamous epithelium)
- Type of mesothelium
- All Serosa make fluid
12
Q
What is the mesothelioma that lines the viscera called?
A
Visceral peritoneum
13
Q
What is the mesothelium that lines the abdominal wall called?
A
Parietal peritoneum
14
Q
How is the GI tract stimulated?
A
Thru the Vagus Nerve (in the PNS)
15
Q
What happens when the vagus nerve is stimulated in relation to the GI tract?
A
The GI Tract stretches due to the presence of food & certain chemicals
16
Q
What is the enteric nervous system?
A
A bunch of intrinsic neurons found in the GI tract
17
Q
What are the two kinds of series found within the Enteric nervous system?
A
1) Submucosal nerve plexus
2) Myenteric Nerve Plexus
18
Q
What is the function of the sub mucosal nerve plexus?
A
Found in submucosa
- Controls glands & muscular is mucosa
19
Q
What is the myentric nerve plexus?
A
Between circular & longitudinal muscle of the muscular is externa
- Controls the movement of the intestines
20
Q
What are the muscles for mastication?
A
Temporal is, mass enter, pterygoids
21
Q
How many muscles are found in the tongue?
A
9
22
Q
What is papillae?
A
Projections that contain most of the taste buds
23
Q
List the 4 types of papillae
A
1) Filiform
2) Fungiform
3) Circumvallate
4) Foliate
24
Q
Describe filiform
A
Smallest papillae on dorsal of tongue to give it friction
- Does not have taste buds.
25
Describe fungi form.
Mushroom shaped: scattered all over dorsal surface of the tongue
26
Describe circumvallate
Only 10-12 near the back of the tongue (largest papillae)
27
Describe foliage
Along the sides of the tongue
28
What are the 6 characteristics of saliva?
1) Amylase
2) Lipase
3) Mucus
4) Lysozyme
5) IgA
6) Defensins
29
What is the function of lipase?
Digests various lipids
30
What is the function of mucus?
Lubricates food
31
What is the function of IgA?
Antibodies (found in milk)
32
What is the function of lysozyme?
Enzyme that kills microbes
33
What is the function of defensins?
Antimicrobial
34
What are the 3 salivary glands?
1) Parotid
2) Submandibular
3) Sublingual
35
Where is the parotid gland found?
In front of earlobe
36
Where is the submandibular gland found?
Body of the mandible
37
Where is the sublingual gland found?
On mandible
38
How is the sublingual gland stimulated?
By the parasympathetic nervous system w/ Acetylcholine as its major neurotransmitter
39
What inhabits Acetylcholine?
Atropine
40
What is deglutition?
Swallowing
41
What are the regions of the stomach?
Cardiac
Fund us
Body
Pyloric
42
What are the functions of the stomach?
1) Activate pepsin & lipase
2) Break down CT & cellulose
3) Convert Fe+++ into absorbable form, Fe++
4) Kills ingested microbes
43
What is chyme?
Contents of stomach
44
What is the acidity of the stomach?
2-3
45
What are the cells found in the stomach?
Goblet/mucus cells
| Parietal/Oxyntic Cells
46
What is the main function of the parietal cells?
Makes HCl
47
What are the steps of making HCl?
1) Type 2 Histamine Receptor
2) Proton Pumps
3) Chloride Shift
48
What happens when the Type 2 Histamine receptor is activated?
G Protein Pathway (cAMP)
| - Moves proton pumps from cytoplasm to cell membrane & activates the proton pumps
49
What happens in the proton pumps?
Pumps H+ ions into lumen
- Exchanges for K+
- The H+ mixes with Cl- in the lumen to make HCl
50
What happens during the chloride shift?
The enzyme carbonic anhydrase makes H+ instead of removing it
- Bicarbonate goes from cell to plasma
- Chloride ion enters gastric lumen to combine with H+
51
How can we reduce the risk of gastro-esophageal reflux?
Histamine receptor type 2 inhibitors
| Proton pump inhibitors
52
What does histamine receptor Type 2 inhibitors do?
Blocks histamine at the H2 receptors of parietal cells to decrease HCl Production
53
What does proton pump inhibitors do?
Stops making HCl
- more effective than H2 inhibitors
- Blocks H+ pump to reduce production of HCl
54
What secretes intrinsic factor?
Parietal or Oxyntic Cells
| Allows intestines to absorb Vitamin B12
55
What does Chief or Zymogen cells do?
It creates pepsinogen
56
What happens to pepsinogen?
It turns into pepsin when in low pH
57
What does pepsin do?
Digests proteins into smaller peptides (still non-absorbable)
58
What does enteroendocrine cells do?
Makes hormones to regulate digestine
59
What hormones does enteroendocrine cells make?
Histamine & Somatostatin
60
What does somatostatin do?
Inhibits gastrin release
61
What does histamine do?
Moves proton pumps from cytoplasm to cell membrane to activate
62
What are the 3 sections of the small intestine?
1) Duodenum (proximal to stomach)
2) Jejunum
3) Illeum (distal-attaches to colon)
63
What is the function of the small intestine?
Absorbs nutrients & secretes hormones
64
What hormones does the small intestine secrete?
Secretin, gastrin, & cholecystokinin
65
What does secretin do?
Releases bicarbonate & protease enzyme: neutralizes acidic pH coming from the stomach & attempting to enter the duodenum
66
What does gastrin do?
Makes stomach make more HCl
| -Released when stomach is becoming more basic.
67
What does cholecystokinin do?
Causes gall bladder to release bile into duodenum of small intestine to help with lipid digestion.
68
What is the function of the rugae of the small intestine?
Increase surface area
69
What are the three kinds of rugae in the small intestine?
- Plicae circularis
- Villi
- Microvilli
70
Describe the plicae circularis
- Visible to eye
| - Increases SA 3x
71
Describe the microvilli
Increases SA by 20x
72
Describe the Villi
Increases SA by 10x
73
How much does rugae overall increase SA by?
600x
74
What are the functions of the liver?
- Extramedullary hemopoiesis
- Gluconeogenesis
- Glyconeogenesis
- Regulates blood glucose
- Glycogenolysis
- Beta Oxidation
- Cori Cycle
- Makes LDLs & HDLs
- Makes Plasma proteins
- Deamination
- Iron Storage
- Detoxification
75
What is gluconeogenesis?
Makes glucose from non-carbs (like proteins)
76
What is beta oxidation?
Breaks up fatty acids into acetyl groups for metabolism
77
What is the Cori Cycle?
Lactic acid made from muscles can be converted to usable pyruvic acid energy
78
How much of your cholesterol is made in the liver versus dietary?
85% Liver 15% Dietary
79
Where is phospholipids made in?
The Liver
80
What is deamination?
Takes out the amino group found in amino acids in order for it to be digested. The amino group is then converted into urea
81
Compare detoxification between a water soluble compound and a non-water soluble compound
Fat-Soluble compounds bypass the liver’s detoxification process while water soluble ones are detoxified by the liver
82
What is the function of bile?
Allows digestion of fats by emulsifying them & turning the fat into small droplets
83
Where is bile stored?
Gall bladder
84
What is cholecystokinin? (CCK)
Made by small intestines
| -Makes the gall bladder to contract to force bile down the duodenum when fat is present
85
Where are HDLs & LDLs made?
The liver
86
Where is iron stored?
The liver
87
What does the pancreas do in relative to GI system?
Produces digestive enzymes & Bicarbonate ions (exocrine function)
- This is along with hormones (relative to endocrine system)
88
Where does the enzymes & bicarbonate ions get released into from the pancreas?
Duodenum
89
What is the function of acinar cells?
Found in the pancreas (outside islet of langerhans)
| - Makes the enzymes & bicarb
90
What enzymes break down glucose that are made in the pancreas?
Amylase, Dextrinase, Glucoamylase, Maltase, Sucrase, Lactase
91
What is dextrinase?
Digests oligosaccharides (3-8 glucose linked together) into glucose
92
How many monosaccharides in an oligosaccharide?
3-8 monosaccharides
93
What is glucoamylase?
Digests oligosaccharides into glucose molecules as well
94
What is trypsinogen?
Becomes trypsin
95
What is trypsin?
Found in pancreas
| - Digests proteins into smaller peptide molecules (not digestable yet)
96
What enzymes are found in the pancreas relative to the digestion of protein?
Trypsinogen (trypsin), Chromotrypsin, peptidase, carboxypeptidase, aminopeptidase, dipeptidase, lipase
97
What enzymes are found in the pancreas that break down nucleic acid?
Ribonuclease, deoxyribonuclease
98
What is the function of peptidase?
Digests peptides, so they can be absorbed (single amino acids)
99
What is the function of carboxypeptidase?
Break off amino acid carboxyl end
100
What is the function of dipeptidase?
Break off dipeptides into amino acid component
101
What is the function of lipase?
Digests triglycerides into 2 fatty acids & 1 monoglyceride
102
When is bicarbonate ion released from pancreas into duodenum
By the hormone secretin released by small intestines
103
Function of alpha cells?
Makes glucagon
104
Function of beta cells
Makes insulin
105
Function of delta cells?
Makes somatostatin (inhibits growth hormone)
106
What is the function of the colon?
Absorb water, make bicarbonate ions, has gut bacteria, makes gases (flatus)
107
What is the function of gut bacteria?
Breaks down fibers, helps make vit. B & K, helps metabolize bile components
108
What is dysbiosis?
Disruption of gut bacteria
109
What causes dysbiosis?
Inflammatory diseases, infections, obesity, autoimmune diseases, & sometimes cancer treatments
110
What is the breakdown of feces into % components?
30% Dead bacteria
30% Fiber
10-20% Fat
10-20% Inorganic material
111
What is anorexia?
Decreased appetite
112
What is bulimia?
Binge eating then self-induced vomiting
113
What stimulates vomiting?
Parasympathetic NS
114
What is projectile vomiting?
Vomiting without retching due to CNS stimulation
115
What could be risk factors/causes for constipation?
Damage to colon, drugs, sedentary lifestyle, depression, too much calcium from antacids, iron supplements
116
What is diarrhea?
Increased frequency & fluid content of defecation
117
What are the five kinds of diarrhea?
Osmotic, secretory, increased motility, intestinal inflammation, & fecal impaction/severe constipation.
118
Describe osmotic diarrhea
Hypertonic intestines with fleet phospha soda
119
What causes osmotic diarrhea?
Due to lactase deficiency (lactose intolerence(?)
- The lactose cannot be absorbed> hypertonic intestines > water follows
- Eating non-absorbable syntehtetic sugars (like sorbitol **possible reason behind too much trident gum>diarrhea?)
120
Describe secretory diarrhea
Usually due to bacterial enterotoxins (E.Coli, cholera)
121
Increased Motility Diarrhea Cause
Fluids have less time to be absorbed
| - Neuropathy & Diabetes causes: loss of motility control
122
Intestinal inflammation Diarrhea causes
IBS (Irritable bowel syndrome), ulcerative colitis (chron’s disease)
123
What are the risks of a hollow organ (intestines) being distended?
Creates immense pain
124
What is distention?
Swelling by pressure from inside
125
What causes distention of intestines?
Gas, inflammation
126
What is hematemesis?
Blood in vomit
127
What is hematochezia?
Apparent blood from the rectum
128
What is melena?
Dark tarry (black) stool
129
What may melena indicate?
Hemorrhage higher up in the alimentary canal
130
What is occult blood?
Small amounts of blood (cannot be seen visibly without staining)
131
What does occult blood indicate?
Slow hemorrhage
132
What is gastroesophageal reflux (GERD)?
The acidic, gastric contents coming up into the esophagus (painful-chronic can lead to esophageal cancer)
133
What is a hiatial hernia?
Herniation (displacement) of the gastric fundus or cardiac zone & protrudes thru the diaphragm into the thorax
134
What is dysphagia?
Difficulty swallowing: leads to increased reflux & epigastric pain
135
What is achlasia?
Decreased muscle of the lower esophagus: leading to an accumlation of food stuck in the esophagus creating esophageal distention
136
What is intussuception?
One part of the intestine slides into another part of the intestine
137
What does intussuception lead to?
Strangulation of blood supply
138
What is torsion?
Twisting of intestines
| - leads to struggle for blood supply
139
What is diverticulosis?
Inflammed herniations of colon
140
Who is diverticulosis more likely to affect?
Obese over 70 years old
141
What is ileus or adynamic?
Loss of motility due to surgery
142
Where is a peptic ulcer found?
Lower esophagus, stomach, duodenum
143
What is a peptic ulcer mainly caused by?
Smoking, NSAIDS, alcohol, rheumatoid arthritis, emphysema, cirrhosis of the liver
144
Where is a peptic ulcer mainly found on?
Duodenum
145
What is a peptic ulcer caused by?
Helicobacter pylori
146
What is an indication of a peptic ulcer?
Pain 2-3 hours after eating in lower esophagus, stomach, or duodenum region
147
What are some inflammatory bowel diseases?
-Chron’s Disease
- Ulcerative Colitis
Both autoimmune
148
What is chron’s disease?
Chronic inflammation with ulcers & scarring of the alimentary canal (especially ileum)
149
What is the function of the ulcerative colitis?
Inflammation with ulceration & scarring of colon & rectum
150
What are some potential conditions that accompany appendicitis?
Gangrene, perforation & peritonitis
151
What is ascites?
Accumulation of fluid in peritoneal cavity
152
What does ascites cause?
Distension (seen in cirrhosis of the liver)
153
What is the cause of jaundice?
Liver is incapable of breaking down billirubin, so it builds up
154
What is metabolic syndrome?
Series of symptoms that increase the likelihood for patients to die.
155
What are some signs & symptoms of metabolic syndrome?
Increased BP
Increase blood glucose levels
Increased body fat
Increased plasma cholesterol & triglycerides
(All increases risk of stroke, diabetes & CVD)
