Ch.23 Digestive tract Flashcards
1
Q
Glands in the _____ and body produce most gastric juice
A
fundus
2
Q
Glands in the stomach include _____ cells
A
secretory
3
Q
“Secrete thin, acidic mucus of unknown function” describes….
A
Mucous neck cells
4
Q
Which cells of the stomach secrete hydrochloric acid?
A
Parietal cells
5
Q
What is the pH range of the stomach?
A
1.5-3.5
6
Q
What does HCl do in the stomach?
A
Denatures protein, activates pepsin, breaks down plant cell walls, and kills many bacteria
7
Q
“Denatures protein, activates pepsin, breaks down plant cell walls, and kills many bacteria” This is the function of _______ in the stomach
A
Hydrochloric acid
8
Q
Is the stomach acidic or basic?
A
acidic
9
Q
Parietal cells secrete the ______ ______, a molecule (glycoprotein) that is fundamental for the absorption of B12
A
intrinsic factor
10
Q
Which cells secrete the intrinsic factor in the stomach?
A
parietal cells
11
Q
_____ cells in the stomach secrete pepsinogen
A
Chief cells
12
Q
“Inactive enzyme that is activates to pepsin by HCl and pepsin itself (positive feedback mechanism)” this describes….
A
Pepsinogen
13
Q
Chief cells secrete pepsinogen as well as ______
A
lipases
14
Q
Pepsinogen turns into pepsin by reacting with _____
A
HCl
15
Q
_________ cells secrete chemical messengers into lamina propria
A
Enteroendocrine cells
16
Q
Why do we have a mucosal barrier?
A
Because harsh digestive conditions….
17
Q
The _____ ______ protects the stomach and is created by three factors
A
mucosal barrier
18
Q
What are the three factors that create the mucosal barrier?
A
Bicarbonate rich-mucus, tight junctions between epithelial cells, and damaged epithelial cells are quickly replaces by division of stem cells
19
Q
_____ cells of the mucosal barrier are replaced every 3-6 says
A
surface cells
20
Q
“Inflammation caused by anything that breaches the stomach’s mucosal barrier”
A
Gastritis
21
Q
______ or _____ ulcers can cause erosions in the stomach wall
A
Peptic or gastric ulcers
22
Q
Most ulcers are caused by bacterium ______ ______
A
helicobacter pylori
23
Q
If erosions perforate the stomach wall, this can lead to _______ and _______
A
peritonitis and hemorrhaging
24
Q
What is the precursor to developing ulcers?
A
Gastritis, which is mucosal inflammation
25
______ ______ creates urease
Heliobacter pylori
26
The stomach delivers chyme to the small intestine. T or F?
True
27
The stomach denatures proteins by ACH. T or F?
False, it's by HCl
28
Does pepsin carry out enzymatic digestion of proteins?
Yes
29
The milk protein, _______, is broken down by ______ in infants
Casein; rennin
30
Casein(milk protein) is broken down by rennin in infants. This results in what?
A curd-like substance
31
Lipid-soluble and _____ are absorbed into blood
aspirin
32
The only stomach function essential to life is secretion of intrinsic factor for B12 absorption. T or F
True
33
B12 is needed for RBC's to _______
mature
34
Lack of _______ _____ causes pernicious anemia
intrinsic factor
35
Gastric mucosa secretes less than ___ L of gastric juice a day
less than 3
36
Gastric mucosa secretion is regulated by......
Gastrin and and gastrin antagonists
37
_____ stimulates the enzyme and HCl secretion
Gastrin
38
What two factors cause pressure to remain constant until at least 1.5L of food is ingested?
Receptive relaxation and gastric accommodation
39
_______ _______: reflex-mediated relaxation of smooth muscle coordinated by the swallowing center of brain stem
Receptive relaxation
40
______ ______: intrinsic ability of smooth muscle to exhibit stress-relaxation....finish slide
Gastric accommodation
41
What is vomiting caused by?
Extreme stretching, intestinal irritants(bacterial toxins, excessive alcohol, spicy food, certain drugs)...finish slide
42
How much bile does the liver produce per day?
approx. 900mL
43
Does the spleen store glucose as glycogen and make plasma proteins?
No, the liver does
44
Does the liver store fat-soluble vitamins?
Yes
45
Bile is a yellow green, ________ solution
alkaline
46
_____ ______: cholesterol derivatives that function in fat emulsification and absorption
Bile salts
47
Bile contains what?
Bile salts
48
Hepatitis is usually a ______ infection
viral
49
Hepatitis can be caused by drug toxicity and poisoning from what?
Wild mushroom
50
"Progressive, chronic inflammation from chronic hepatitis or alcoholism" This describes _____.
Cirrhosis
51
Liver -----> fatty, fibrous ------> ______ ______
portal hypertension
52
**The gallbladder will be on the exam***
(-:
53
Biliary calculi, also known as _______, are caused by too much cholesterol or too few bile salts
gallstones
54
_______ are painful when the gallbladder contracts against sharp crystals
Gallstones
55
What is obstructive jaundice?
Blockage that can cause bile salts and pigments to build up in blood, resulting in jaundiced skin.
56
______ can also be caused by liver failure
Jaundice
57
What is the treatment for gallstones?
Crystal-dissolving drugs, ultrasound vibrations, laser vaporization, or surgery
58
Lithotripsy is ______ ______, which is a treatment for gallstones
ultrasound vibrations
59
Which organ is the most retroperitoneal?
Pancreas
60
What is the exocrine function of the pancreas?
To produce pancreatic juice
61
_____ is found on the pancreas and is a cluster of secretory cells that produce zymogen granules containing proenzymes
Acini
62
Which part of the pancreas produces zymogen granules?
Acini
63
What is the endocrine function of the pancreas?
Secretion of insulin and glucagon by pancreatic islet cells
64
How much pancreatic juice is produced a day?
1200-1500mL/day
65
"Continuous muscular tube that runs from the mouth to the anus" this describes the
Alimentary canal
66
What are the three other names for the alimentary canal?
Gastrointestinal, GI tract, or gut
67
What are the six essential activities of the digestive process?
Ingestion, propulsion, mechanical breakdown, digestion, absorption, and defecation
68
Step one of the six essential activities is simply ____
eating
69
What is the second essential activity?
Propulsion: movement of food through the alimentary canal
70
Propulsion includes ______ and peristalsis
swallowing
71
What is peristalsis?
The major means of propulsion of food that involves alternating waves of contraction and relaxation
72
the __ step, mechanical breakdown, includes chewing, mixing food with ____, churning food in stomach, and segmentation
3rd, mixing food with saliva
73
What is segmentation? which step does it occur in?
3rd step. It is the local constriction of intestine that mixes food with digestive juices
74
The 4th step, ______, is a series of catabolic steps that involves enzymes that break down complex food molecules into chemical building blocks
Digestion
75
_______, the 5th step, is the passage of digested fragments from lumen of GI tract into blood or lymph
Absorption
76
______, the 6th and final step, is elimination of indigestible substances via anus in form of feces
Defecation
77
______: serous membranes of abdominal cavity
Peritoneum
78
The peritoneum consists of the ______ and ________ peritoneum
visceral and parietal peritoneum
79
Which peritoneum is the membrane on the external surface of most digestive organs?
Visceral
80
Which peritoneum is the membrane that lines the body wall?
Parietal
81
What is the function of the peritoneal cavity?
The fluid lubricates mobile organs
82
What is the mesentery?
A double layer of peritoneum, layers are fused back to back
83
"Extends from body wall to digestive organs" this describes the ______
Mesentery
84
"Provides routes for blood vessels, lymphatics, and nerves" this describes the _____
mesentery
85
"Holds organs in place and also stores fat" this describes the _____
mesentery
86
________ organs: organs that are located within the peritoneum
Intraperitoneal
87
_____ organs: located outside, or posterior to the peritoneum
Retroperitoneal
88
Which organs are retroperitoneal?
Pancreas, duodenum, and parts of large intestine
89
Inflammation of the peritoneum is called ______
peritonitis
90
What causes peritonitis?
Piercing abdominal wound, perforating ulcer, or ruptured appendix
91
With peritonitis, what structure helps localize infection?
The peritoneal coverings, which stick together
92
Can peritonitis become lethal?
Yes, if it becomes widespread
93
What is the treatment for peritonitis?
Debris removal and megadoses of antibiotics
94
All digestiv organs have the same four basic layers or "tunics" what are they?
Mucosa, submucosa, muscularis externa, and serosa
95
Which tunic lines lumen?
Mucosa
96
What are the three main functions of the tunics?
Secretion, absorption, and protection
97
The mucosa secretes ______, _______ _____, and _______
mucus, digestive enzymes, and hormones
98
The first tunic, the mucosa, has how many sublayers?
three
99
What are the three sublayers that make up the mucosa?
Epithelium, lamina propria, and muscularis mucosae
100
The epithelium layer of the mucosa is simple columnar and has mucus secreting cells in most of tract. T or F
True
101
The mouth _____, and anus are made up of stratified squamous epithelium
esophagus
102
The _____ of the mucosa secretes mucus which protects digestive organs from enzymes
Epithelium
103
The _____ ____ sublayer of the mucosa is made up of loose areolar connective tissue
lamina propria
104
What kind of tissue is the lamina propria made up of?
Loose areolar connective
105
The lamina propria sublayer of the mucosa has a rich supply of what that is needed for nourishment and absorption?
Rich supply of capillaries
106
The _____ _____ also contains lymphoid follicles that help defend against microorganisms.
Lamina propria
107
The _____ _____ of the mucosa is the smooth muscle that produces local movements of mucosa
Muscularis mucosae
108
The _______ consists of areolar connective tissue and has an abundant amount of elastic tissues that help organs to regain shape after storing large meals
submucosa
109
The submucosa contains blood and lymphatic vessels, land lymphoid follicles that supply surrounding GI tract tissues. T or F
True
110
The mucosa has abundant amounts of elastic tissues that help organs to regain shape after storing large meals. T or F?
False, the submucosa contains the elastic tissues
111
Which layer of GI organs is responsible for segmentation and peristalsis?
The third, muscularis externa
112
The _____ _____ contains inner circular muscle layer and outer longitudinal layers
Muscularis externa
113
Circular layer of the _____ _____ thickens in some areas to form sphincters
muscularis externa
114
The outermost layer of GI organs, the ______, is made up of the visceral peritoneum
serosa
115
The serosa is formed from what?
formed from areolar connective tissue covered with mesothelium in most organs
116
Splanchnic circulation includes _____ _____ circulation, which drains nutrient rich blood from digestive organs and delivers blood to liver for processing
hepatic portal circulation
117
What does the hepatic portal circulation do? (two)
1. Drains nutrient rich blood from digestive organs
| 2. Delivers blood to liver for processing
118
Does the GI tract have its own nervous system?
Yes
119
What is the GI tract nervous system referred to as?
The enteric nervous system
120
Does the enteric nervous system contain more neurons than the brain?
No, but it contains more neurons than the spinal cord
121
The gut brain is made up of _____ neurons that communicate extensively with each other
enteric
122
Enteric neurons are the major nerve supply to GI tract wall that controls _____
motility (The ability of an organism to move independently, using metabolic energy)
123
What are the two key concepts to regulating GI activity?
1. Digestive activity is provoked by a range of mechanical and chemical stimuli
2. Effectors of digestive activity are smooth muscle and glands
124
Explain the concept "digestive activity is provoked by a range of mechanical and chemical stimuli"
There are receptors in the walls of GI tract organs that respond stretch, changes in osmolarity and pH, and presence of substrate and end products of digestion
125
Explain the concept "effectors of digestive activity are smooth muscle and glands"
When stimulated, these receptors initiate reflexes that stimulate smooth muscle to mix and move lumen contents. Reflexes can also activate or inhibit digestive glands that secrete digestive juices or hormones
126
Functions of saliva?
Clean mouth, dissolve food chemicals for taste, moistens food to compact it into bolus, and begin breakdown of starch with enzyme amylase
127
Which enzyme in the mouth breaks down starch?
Amylase
128
Most saliva is produced by what?
Major salivary glands located outside of oral cavity
129
What are the major salivary glands?
Parotid, submandibular, and sublingual(under tongue)
130
Where is the parotid salivary gland?
Anterior to ear and external to masseter muscle
131
Where is the submandibular salivary gland?
Medial to body of mandible (duct opens at base of lingual frenulum)
132
Where is the sublingual salivary gland?
Anterior to submandibular gland under tongue (opens via 1-212 ducts into floor of mouth
133
What two cells are salivary glands composed of?
Serous and mucous cells
134
What do serous cells of salivary glands produce?
watery secretion, enzymes, ions, and a bit of mucin
135
The parotid and submandibular glands contain mostly _____ cells, but the sublingual gland consists mostly of _____ cells
serous; mucous
136
What are mumps?
Inflammation of parotid glands caused by the mumps virus (myxovirus)
137
Mumps is a common adult disease. T or F
False, common children's disease
138
Mumps spreads via ____
saliva
139
Symptoms of mumps?
Pain when opening mouth, moderate fever, and pain when swallowing acidic foods.
140
Mumps in adult males carry a 25% risk of what?
Of infecting the testes too, which can lead to sterility
141
Saliva contains water and ______
electrolytes
142
Is saliva 85%-95% water?
No, 97-99.5% water
143
Is saliva slightly acidic or basic? what is the range?
Acidic ph 6.75-7.00
144
Which two enzymes are found in saliva?
Amylase and lingual lipase
145
Which proteins are found in saliva?
Lysozyme, mucin, and IgA
146
What metabolic wastes are found in saliva?
Urea and uric acid
147
(in saliva ) Lysozyme, IgA, _______, and ____ _____ from nitrates in food protect against microorganisms
Defensins and nitric oxide
148
How much saliva do you usually produce a day?
1500mL
149
Do minor or major glands continuously keep mouth moist?
Minor
150
Major salivary glands are activated by the sympathetic nervous system. T or F
False....parasympathetic
151
Strong sympathetic stimulation inhibits salivation and results in dry mouth (xerostomia) T or F
True
