Module 18: Digestive System Flashcards
1
Q
The body’s mechanism for processing and absorbing nutrients, biochemical substances that are necessary for life is:
A
The Digestive System
2
Q
The anatomical structure that carries out the functions of the Digestive System is called the:
A
The Gastrointestinal (GI) tract or The Alimentary Canal
3
Q
The functions of the digestive system include:
A
- ingestion
- secretion
- mixing and propulsion
- digestion
- absorption
- defacation
4
Q
To take in food is called:
A
Ingestion
5
Q
To release substances that will help in the breakdown and absorption of nutrients is called:
A
Secretion
6
Q
Ensuring that chemicals and foods are mixed to promote breakdown, and moving things along is called:
A
Mixing and Propulsion
7
Q
Breaking down foods is also called:
A
Digestion
8
Q
Transferring nutrients from the GI tract to the bloodstream is also called:
A
Absorption
9
Q
Removing waste matter from the body is called:
A
Defacation
10
Q
4 layers of the GI tract from deep to superficial
A
Mucosa
Submucosa
Muscularis
Serosa
11
Q
The inside of the GI tract
A
Lumen
12
Q
The outside of the GI tract
A
Serous membrane
13
Q
Layers of the mucosa from deep to superficial
A
Epithelium
Lamina Propria
Muscularis mucosae
14
Q
Stratified squamous in the mouth and simple columnar in the stomach and intestines (layer of mucosa)
A
Epithelium
15
Q
A layer of areole connective tissue with blood and lymphatic vessels to pick up material absorbed by epithelium (layer of mucosa)
A
Lamina propria
16
Q
A thin muscle layer that makes the inside of the GI tract all crinkly and folded (layer of mucosa)
A
Muscularis mucosae
17
Q
This layer of the GI tract comprises areole connective tissue. In it, we find blood and lymphatic vessels and the submucosal plexus of the enteric nervous system
A
Submucosa
18
Q
This layer of the GI tract is striated and voluntary muscle in the mouth and pharynx to control swallowing. Smooth, involuntary muscle lines the rest of the GI tract and keeps materials moving through peristalsis
A
Muscularis
19
Q
What kind of muscle in the mouth and pharynx controls swallowing
A
Striated, voluntary
20
Q
What kind of muscle lines the rest of the GI tract and keeps materials moving through peristalsis
A
Smooth, involuntary
21
Q
This layer of the GI tract is made up of areolar connective tissue covered by a simple squamous epithelium. In the abdominal cavity, this is called the visceral peritoneum because it forms the “guts” side of the peritoneal cavity
A
Serosa
22
Q
What is the serosa called in the abdominal cavity
A
Visceral peritoneum
23
Q
Non-taste structures that give the tongue a rough texture. They also look like little threads and cover most of the tongue’s surface
A
Filiform papillae
24
Q
Three groupings where taste buds are found
A
Fungiform papillae(mushrooms)
Foliate papillae(leaf-shaped…lateral & posterior)
Vallate(V-shaped, surrounded by a wall)
25
Function of lingual glands
Secrete mucus plus an enzyme, lingual lipase = helps break down fatty food in mouth
26
What kind of muscle is the tongues
Skeletal, voluntary
27
3 divisions of the pharynx
Nasopharynx
Oropharynx
Laryngopharynx
28
This structure connects the paranasal sinuses to the pharynx, allowing air to pas from nose to trachea
Nasopharynx
29
This structure of the pharynx joins the nasal cavity and oral cavity to the gut tube and trachea
Oropharynx
30
In this structure of the pharynx the epiglottis covers the trachea when swallowing food or drink, and covers the esophagus when breathing
Laryngopharynx
31
The process that moves food in the GI tract
Peristalsis
32
3 phases of swallowing
Voluntary
Pharyngeal: bolus is in the oro- and laryngo-. The stage where food and water are kept out of trachea
Esophageal: upper esophageal sphincter open, and the autonomic process of peristalsis begins
33
An elastic flap that covers the esophagus when breathing and covers the trachea when swallowing
Epiglottis
34
Function of carbonic anhydrase
Turn CO2 and H2O in the stomach into carbonic acid(H2CO3)
35
HCL Secretion by Parietal Cells of the stomach
* secrete HCL acid to aid in digestion and protect from invaders
* making H+ ions
* making Cl- ions
36
Failure of the pancreas to make bicarbonate =
Duodenal ulcers
37
Function of proton-pump inhibitors
Reduce the secretion of H+CL- by parietal cells and can reduce symptoms of GERD
38
Neurotransmitters/hormones that up-regulate HCL secretion
- ACH from parasympathetic stimulation (vagus nerve)
- gastrin from G cells
- histamine from mast cells in lamina propria (via H2 receptors)
39
Absorption of nutrients of sugars/carbohydrates
1. Enzymes convert di and polysaccharides to glucose, galactose, and fructose
2. Glucose, galactose pumped into intestinal cell cytoplasm; fructose moves into intestinal cell cytoplasm
3. From intestinal cell to bloodstream by facilitated diffusion
40
How does glucose and galactose get into cell cytoplasm
Secondary active transport
41
How does fructose get into cell cytoplasm
Facilitated diffusion
42
Absorption of nutrients of proteins
1. Enzymes convert proteins to amino acids, di-, tripeptides
2. These pumped into intestinal cell cytoplasm by secondary active transport
3. From intestinal cell to bloodstream by simples diffusion
43
Absorption of nutrients of short-chain fatty acids
Simples diffusion from lumen to intestinal cell cytoplasm to bloodstream
44
Absorption of nutrients of long-chain fatty acids and monoglycerides
1. Insoluble in water: carried in bloodstream in balls called micelles
2. Move into intestinal cell cytoplasm by simple diffusion
3. Bile emulsifies fat and intestinal cell forms it into triglycerides, which are packaged in chylomicrons and dumped into lacteals(lymph vessel in core of villus)
45
Equation for lactose
Glucose + galactose
46
Equation sucrose
Glucose + fructose
47
Function of ileocecal sphincter
Allows material to pass from ileum of small intestine to cecum of large intestine
48
Cells types of the large intestine
Absorptive(absorbs water)
| Goblet(secretes mucus)
49
Function of internal anal sphincter
Involuntary
50
Function of external anal sphincter
Voluntary
51
Which lobes of the liver can you see from an anterior view
Right and Left
52
Which lobes of the liver can you see from the posterior view
Caudate and quadrate
53
3 connective tissue(ligaments) that hold the liver in place
Falciform ligament
Coronary ligament
Round ligament
54
Hepatocytes
Inactive toxins
| Produce bile and a variety of blood proteins
55
Kupffer cells
Macrophages of liver
| Destroy RBCs and invaders
56
Bile canaliculi
Bile travels in these tiny vessels to join at the bile duct
57
The portal triad
Branch of hepatic portal vein
Branch of hepatic artery
Bile duct
58
What is the real functional unit of the liver (as so we think)
Hepatic acinus(2 1/6 slices of the lobule working together)
59
What's the histological unit of the liver
Hepatic lobule (hexagon)
60
Pathway for Bile
Secreted by hepatocytes ➡️ flows into bile canaliculi ➡️ bile duct ➡️ R lobe into R hepatic duct, L lobe into L hepatic duct ➡️ common hepatic duct ➡️ cystic duct ➡️ gallbladder(stored here) ➡️ out cystic duct(again) ➡️ common bile duct(to join pancreatic juices) ➡️ duodenum(sphincter of the hepatopancreatic ampulla)
61
Pathway for unconjugated bilirubin
Spleen uses enzyme heme oxygenase to convert heme to biliverdin ➡️ converts to bilirubin ➡️ gloms onto blood protein albumin and carried to liver (insoluble in blood)
62
Pathway for conjugated bilirubin
In liver ➡️ conjugated to small molecule glucoronic acid (water-soluble) ➡️ makes up major portion of bile ➡️ intestines where intestinal bacteria remove glucoronic acid ➡️ converts to urobilinogen ➡️ some reabsorbed back into circulation, rest further broken down by bacteria = stercobilin = gives feces brown color
63
3 phases of digestion
Cephalic
Gastric
Intestinal
64
Phases of Cephalic phase
Stimulation: smell, taste, sight, thought of food
Action: brain prepares body for meal
Result: CN VII, CN IX stimulate salivation; CN X(Vagus) stimulate stomach acid secretion
65
Phases of gastric phase
Stimulus: stomach wall stretches or pH increases
Action: increase gastric motility and secretion of HCL
Result: stomach empties into duodenum as food is digested
66
Phases of intestinal phase
Stimulus: chyme in duodenum
Action: activation of enterogastric reflex
Result:
- starch receptors in duodenal wall signal medulla
- medulla inhibits parasympathetic ACh release from vagus
- ⬇️ gastric motility, ⬆️ tone in pyloric sphincter
• more chyme stays in stomach, less enters duodenum(long reflex)
67
Gastrin
Made by: G cells
Acts on: stomach
Action: promote secretion of gastric juices
68
Cholecystokinin
Made by: enteroendocrine cells of small intestine
Acts on: gallbladder, pancreas, brains
```
Action:
• ejection of bile
• opening of sphincter of hepatopancreatic ampulla
• more pancreatic juice
• feel full
```
69
Secretin
Made by: enteroendocrine cells (S cells) of duodenum
Acts on: pancreas
Action: more bicarb in pancreatic juice
70
Glucose-dependent insulinotropic peptide (GIP)
Made by: enteroendocrine cells (K cells) of duodenum and jejunum
Act on: beta cells of pancreatic islets
Action: ⬆️ insulin secretion
71
Histamine
Made by: mast cells of lamina propria
Act on: parietal smells of stomach
Action: ⬆️ acid secretion
72
Somatostatin
Made by: hypothalamus
Acts on: many digestive organs
Action:
• ⬇️ exocrine pancreas
• ⬇️ many hormones
• slows gastric emptying
73
Motilin
Made by: enteroendocrine cells (M cells) of duodenum and jejunum
Action:
• ⬆️ migrating myoelectric complex
• ⬆️ pepsin
• ⬆️ bowel motility
74
By coordinating peristalsis, the GI tract keeps things moving through the large intestine to anus
Mass peristalsis
75
The alternating contraction and relaxation
Segmentation
76
Controls motor neurons innervation the longitudinal and circular muscle layers of the muscularis and sends axons to the submucosal plexus, where motor neurons innervate small, weak muscles that give the mucosal epithelium its wrinkles
Myenteric plexus
77
Peristalsis
* A traveling wave of contraction
| * results in mass movement
78
If scientists record the electrical activity of the muscles at a single point in the bowel wall, they see waves of contraction and relaxation. If they observe electrical activity along a length of bowel wall, each of these waves appears to move forward in the GI Tract. This is called ________.
Migrating myoelelectric complex
79
Laxatives
Increase GI motility
80
3 factors that can increase bowel motility
Chyme volume
Chemical composition
Osmolarity
81
Chyme volume
Increase in chyme volume = increases motility
82
Chemical composition
Chemicals that increase electrical activity increase motility
83
Osmolarity
If non-absorbable chemicals are >300mOsm/kg, water is "drawn" into lumen
84
If the intestines fail to absorb water _____ results
Diarrhea
85
Is the intestines absorb too much water ______ results
Constipation
86
Includes all the mixing, moving, churning, matching, and ripping forces
Mechanical digestion
87
Chemicals and enzymes acting on food
Chemical digestion
88
Role of oral cavity in mechanical digestion
- chews food, tongue and cheeks move tongue
| - swallowing mixes food
89
Role of oral cavity in chemical digestion
- salivary glands secrete enzymes that break down starches and fats
90
Esophagus in mechanical digestion
- peristalsis mixes food
91
Esophagus in chemical digestion
None
92
Stomach in mechanical digestion
- contractions of stomach mix food
| - Rugae help with mixing
93
Stomach in chemical digestion
- HCL breaks down foods
- pepsin breaks down proteins
- gastric lipase breaks down fats
94
Small intestine in mechanical digestion
- peristalsis mixes food
| - plicae ciculares aid in mixing
95
Small intestine in chemical digestion
- pancreas releases bicarbonate to neutralize acid + enzymes to break down food
- bile salts from liver emulsify fats
- wide variety of enzymes
96
Large intestine in mechanical digestion
- peristalsis mixes food
| - haustra aid in mixing (haustra live churchinf)
97
Large intestine in chemical digestion
- beneficial bacteria make vitamin K, digest cellulose (fiber), make methane
98
What's the brush border
Where carbohydrates, proteins, and lipids (intestinal enzymes) are found
99
Salivary amylase
Starches
Secreted by salivary glands
100
Pepsin
Proteins
Secreted by stomach
101
Lipase
Triglycerides (fats & oils)
Secreted by stomach
102
Amylase
Starches
Secreted by pancreas
103
Trypsin, Chymptrypsin, Elstase
Proteins
Secreted by pancreas
104
Carboxypeptidase
Amino acids at carboxyl end of proteins
Secreted by pancreas
105
Maltase, sucrase, lactase
Maltose, sucrose, lactose
Found in small intestinal brush border
106
Amino peptidase
Amino acid at amino end of proteins
Found in small intestinal brush border
107
Nucleosidases and phosphatases
Nucleotides
Found in small intestinal brush border
108
Alpha cells
Glucagon
109
Beta cells
Insulin
110
Delta cells
Somatostatin
111
F cells
Pancreatic polypeptide
112
Epsilon cells
Ghrelin3
113
Deciduous teeth
Primary/Baby - 20
114
Permanent teeth
Adult - 32
115
How to number permanent teeth
1 starts on most distal maxillary molar on patient's R (refer to objective 3) and continue around the upper jaw until most distal left maxillary molar, then continue on L side on bottom to most R molar 32
116
How to number primary teeth
A-T in same design as permanent teeth
117
Incisors
Sharp cutting teeth
118
Cuspids
Canine - Point, spear
119
Bicuspids
Premolars
120
Molars
Grindstones
121
The part of the tooth above the gum line and visible
Crown
122
The part of the tooth just below the gumline
Neck
123
The part of tooth that attaches to the periodontal ligaments and then to the jawbone
Root
124
The outer part of the tooth, forming the occlusal surface, and all four sides of the tooth
Enamel
125
Deep to the enamel-makes up majority of tooth
Dentin
126
Denton contains ______ which allow fluid to move
Dentinal tubules
127
The dentin of the root is covered by ______ and is connected to bone by a series of _______, a dense fibrous connective tissue
Cementum, periodontal ligaments
128
The pain fibers and blood vessels of tooth are enclose in the
Pulp cavity
129
Three outlets of in the tooth
Apical foramina
130
The pain signals carted by the nerve fibers in tooth are carried on which cranial nerve
V: trigeminal
131
The largest gland
Parotid gland
132
Salivary gland beneath the tongue
Sublingual gland
133
Salivary gland on the floor of the mouth medial and inferior to the mandible
Submandibular gland
134
3 salivary glands
Parotid
Sublingual
Submandibular
135
Mucus acini
Make mucus
136
Serous acini
Make enzymes in a watery fluid
137
3 enzymes in saliva
Lysozyme: break invading microbes
IgA: immunoglobulin in body secretions
Salivary amylase: break starches into sugars
138
From most water to most mucusy list the salivary glands
Parotid
Submandibular
Sublingual
139
A muscular tube in the mediastinum of the thorax
Esophagus
140
2 layers in the muscularis of the esophagus
Circular: closes off lumen when contracted
Longitudinal: contracts in waves(peristalsis) to move things along
141
The "valve" that allows substances to pass from the pharynx to esophagus
Upper esophageal sphincter
142
The "valve" between the esophagus and stomach
Lower esophageal sphincter(cardiac sphincter)
143
What kind of muscle is the superior 1/3 of the esophagus
Striated voluntary
144
What kind of muscle is lower 2/3 of esophagus
Smooth involuntary
145
Food and liquid leaving the esophagus pass through the _________________ as they enter the stomach. Sometimes it fails to tightly close, causing a condition called _______________.
Lower esophageal/cardiac sphincter, gastro-esophageal reflux disease (GERD)
146
Represents the end of the stomach and outlet for stomach contents. It open into the duodenum.
Pyloric sphincter
147
What are gastric pits
The form of the specialization after the mucosa layer digests food
148
What are gastric glands
The glandular cells in the bottom half of each gastric pit
149
Surface mucous cell
Secreted mucus
150
Mucous neck cell
Secreted mucus
151
Parietal cell
Secreted HCL acid and intrinsic factor
152
Why is intrinsic factor critical
For absorption of vitamin B12(needed for RBC production)
153
Decreased production of intrinsic factor leads to _________
Pernicious anemia
154
Chief cells
Secretes pepsinogen and gastric lipase
155
G cells
Secrete hormone gastrin
156
What is the enteroendocrine system
A kind of hormonal system in GI tract
157
Oblique muscle layer
* "Extra" layer in thick muscularis.
* Aids in stomach's ability to churn substances
* speed digestion
158
"Circular folds" of the lumen in small intestine
Plicae circularis
159
Finger-like projections in small intestines for absorption and increase in surface area
Villi
160
Coats villi's epithelial cells, small version of villi
Microvilli
161
Absorptive cell of small intestine
Absorbs nutrients
162
Goblet cells of small intestine
Secreted mucus
163
Enteroendocrine cell of small intestine
Secreted the hormones secretin, CKK, or GIP
164
Paneth cell of small intestine
Secreted lysozyme, and is capable of phagocytosis
165
Cells of the stomach
```
Surface mucous
Mucous neck
Parietal
Chief
G
```
166
Cells of small intestine
Absorptive
Goblet
Enteroendocrine
Paneth
167
Absorbed directly by stomach and intestines
Water-soluble
168
Absorbed with help of intrinsic factor secreted by parietal cells of stomach
Water-soluble vitamin B12
169
Made by bacteria in large intestine, aids in blood clotting
Fat-soluble vitamin K
170
Defecation reflex is triggered by _______ of the rectum
Distension(enlargement)
| Example: enema to trigger defecation
171
A group of techniques that increase intra-abdominal pressure
Valsalva maneuver
172
Phases of valsalva maneuver in defecation
1. Straining = ⬆️ systolic arterial pressure (transient)
2. Continued straining = ⬇️ arterial pressure, ⬆️ heart rate
3. As strain is released = ⬇️ arterial pressure, ⬆️ heart rate to maximum
4. ⬇️ heart rate "overshoots" before return to normal heart rate and blood pressure
173
Oxygenated blood to liver from
Heart through hepatic artery
174
Deoxygenated blood with absorbed nutrients to liver from
Digestive organs through hepatic portal vein
175
Blood minus toxins plus proteins made by liver is dumped into the
Hepatic vein --> inferior vena cava
