Chapter 22 Flashcards
1
Q
digestive system
A
organ system responsible for digestion and the processing of food, extracting nutrients, and eliminating residue
2
Q
five stages of digestion
A
ingestion, digestion, absorption, compaction, defecation
3
Q
ingestion
A
selective process of food intake
4
Q
digestion
A
breakdown of food into a form that is useable by the body
5
Q
absorption
A
uptake of nutrients from food by absorption into the epithelial cells of the digestive tract, then into blood and lymph
6
Q
compaction
A
absorbing water and consolidating indigestible residue to form feces
6
Q
defecation
A
elimination of feces
7
Q
mechanical digestion
A
physical breakdown of food into smaller particles through chewing and churning
8
Q
chemical digestion
A
hydrolysis reactions that break down macromolecules into monomers by digestive enzymes
9
Q
chemical digestion is required in absorption of all nutrients except for
A
vitamins, amino acids, minerals, cholesterol, and water`
10
Q
alimentary canal
A
muscular tube from the mouth to anus
11
Q
alimentary canal is also called
A
the digestive or gastrointestinal tract
12
Q
organs in the alimentary canal
A
mouths, pharynx, esophagus, stomach, small intestines, large intestines
13
Q
accessory organs of the digestive tract
A
teeth, tongue, salivary glands, liver, gallbladder, pancreas
14
Q
walls of the alimentary canal
A
mucosa, submucosa, muscularis externa, serosa or adventitia
15
Q
layers of the mucosa
A
epithelium, lamina propia, mucosae
16
Q
submucosa
A
thin layer of loose connective tissue that allows passage of blood vessels
17
Q
the submucosa contains what
A
submucosal nerve plexus
18
Q
muscularis externa
A
two muscular layers responsible for movement of stuff through the alimentary canal
19
Q
arrangement of the layers of the muscularis externa
A
inner circular layer and outer longitudinal layer
20
Q
serosa are found
A
in alimentary canal organs within the abdominal cavity
21
Q
the serosa is composed of
A
areolar connective tissue and a simple squamous outer layer
22
Q
the serosa attaches to
A
the mesentery of the periosteum
23
Q
Adventa is found
A
in the alimentary canal outside of the abdominal cavity
24
the adventitia is composed of
fibrous connective tissue
25
peritoneum
lining of the abdominal cavity
26
the peritoneum is composed of
connective tissue lined with simple squamous epithelium
27
the peritoneum contains
vessels and nerves to supply the abdomen
28
layers of the peritoneum
parietal and visceral
29
parietal peritoneum
outer layer lining the abdominal wall
30
visceral peritoneum
inner layer lining the abdominal organs
31
mesentary
visceral peritoneum lining the alimentary canal that attaches to the serosa
32
enteric nervous system
regulates motility, secretion, and blood flow from the esophagus through the intestines
33
is the enteric nervous system dependent or independent
independent of the CNS but influenced by the ANS
34
submucosal plexus controls
secretion from mucosa glands and movement of mucularis mucosae
35
where is the submucosal plexus located
submucosa
36
myenteric plexus controls
contractions of muscularis externa and contains parasympathetic ganglia
37
where is the myenteric plexus located
between layers of muscularis externa
38
myenteric reflexes are known as
short reflexes
39
myenteric reflexes
stretch or chemically stimulate myenteric plexus to trigger peristalsis
40
vasovagal reflexes are known as
long reflexes
41
vasovagal reflexes
parasympathetic stimulation of the digestive tract to target myenteric nerve plexus and other organs
42
stomach acid secretes
HCl
43
stomach acid secretion process
histamine made by enterochromaffin cells in the stomach help stimulate HCl secretion
44
G-cells function
make gastrin when the stomach is distended by food to stimulate HCl production
45
oral cavity is also called
buccal cavity or mouth
46
functions of the oral cavity
ingestion, taste, mechanical digestion, chemical digestion
47
mechanical digestion of the oral cavity
chewing
48
chemical digestion of the oral cavity
saliva
49
bolus
chewed, saliva-mixed food that is swallowed
50
epithelium of the oral cavity
stratified squamous
51
epithelium of the hard palate and gums
keratinized stratified squamous
52
functions of saliva
moisten mouth, prevent cavities, dissolve food molecules to stimulate taste buds, begin chemical digestion
53
cavities are caused by
acid made by bacteria
54
how does saliva prevent cavities
saliva lysosomes kill bacteria that produce acid, IgA antibodies inhibit bacterial growth, saliva buffers acid and remineralizes enamel
55
salivary gland
secrete saliva
56
parotid is located
pair of glands inferior and anterior to ears
57
what saliva gland makes the most saliva
parotid gland
58
submandibular gland is located
inferior to mandibular angular
59
location of sublingual glands
inferior to the tongue
60
saliva chemical digestion enzymes
salivary amylase, lingual lipase
61
salivary amylase digests
starch
62
lingual lipase digests
fats
63
what activates lingual lipase
stomach acid
64
how much saliva is produced per day
1-1.5 Liters
65
salivation is regulated by
the salivatory nuclei
66
where is the salivatory nuclei located
in the oblongata and pons
67
what stimulates the salivation
odor, sight of food, thought of food, flavor,chewing
68
the salivatory nuclei sends signals through
the facial and glossopharyngeal nerves
69
parasympathetic signals from the salivatory nuclei stimulates
secretion
70
sympathetic signals from the salivatory nuclei stimulates
less secretion, more nucleus
71
pharynx
muscular funnel connecting the oral cavity to esophagus
72
the pharynx is part of what to body systems
respiratory and digestive
73
esophagus anatomy
muscular tube connecting the pharynx to the stomach
74
peristalsis
an involuntary wave of muscle contractions pushing food that is the final phase of swallowing
75
functions of the stomach
food storage and gastric digestion
76
how much food can the stomach store
1-4 liters
77
gastric digestion
mechanical churning and chemical digestion of proteins and fats to produce chyme
78
chyme
semi-digested food that goes to the small intestine
79
most digestion and absorption occurs
in the small intestines
80
layers of the muscularis externa
inner oblique, middle circular, outer longitudinal
81
the muscularis externa is made of
smooth muscle
82
the stomach is made of what type of epithelium
simple columnar epithelium covered with mucous to protect from stomach acid
83
gastric pits
depressions in gastric mucosa
84
most numerous cell type in the stomach
chief cells that secrete gastric enzymes
85
gastric enzymes
gastric lipase and pepsinogen
86
gastric lipase
breaks down fats
87
pepsinogen
a zymogen activated by HCl that forms pepsin
88
zymogen
inactive enzyme activated by the removal of an amino acid
89
pepsin
enzyme that chemically digests protein
90
gastric juice
mix of water, HCl, pepsinogen, gastric lipase, and intrinsic factor
91
how much gastric juice is produced per day
2-3 Liters
92
HCl is secreted by
parietal cells
92
functions of HCl in the stomach
breaks up bolus, activate digestive enzyme, disease resistance
93
how does HCl break up bolus
how is bolus broken up liquefication into chyme and protein denaturing
94
what enzymes are activated by HCl
activation of lingual ligase and turning pepsinogen to pepsin
95
how does HCl in the stomach contribute to disease resistance
destroys ingested pathogens
96
intrinsic factor
glycoprotein secreted by parietal cells
97
why is intrinsic factor needed
to absorb vitamin B12
98
what is vitamin B12 needed for
hemoglobin synthesis in the body
99
the only indispensable function of the stomach
using intrinsic factor to absorb vitamin B12
100
segments of the small intestine
duodenum, jejunum, ileum
101
segments of the small intestine from proximal to distal
duodenum, jejunum, ileum
102
main function of small intestine
most chemical digestion and absorption occurs here
103
duodenum receives what material
chyme from the stomach, bile from the liver/gallbladder, and digestive enzymes from the pancreas
104
bile
yellow/green fluid containing bile salts, cholesterol, bile rubin
105
bile salts
steroids that emulsify fats
106
bile is synthesized from
cholestrol
107
emulsification
aid in fat digestion and absorbtion
108
liver
produces and secretes bile
109
gallblader
stores and concentrates bile
110
pancreas anatomy
spongey gland that is inferior and posterior to the great curvature of the stomach
111
is the pancreas an endocrine or exocrine gland
both, but mostly exocrine
112
endocrine function of the pancreas
insulin, glucagon, somatostatin, and hormone release
113
exocrine function of the pancreas
secrete pancreatic juice
114
how much pancreatic juice is secreted per day
12-1500 mL per day
115
pancreatic juice
mix of water, enzymes, bicarbonate, electrolytes, zymogens
116
where is the pancreatic juices secreted to
into pancreatic duct
117
purpose of bicarbonate
buffers stomach HCl
118
zymogens
inactive enzymes
119
zymogens from the pancreas
trypsinogen, Pro carboxypeptidase
120
trypsinogen
converted to trypsin in order to digest proteins
121
what does trypsin do after being activated
converts more trypsinogen to trypsin
122
procarboxypepdatidase
digests proteins as carboxypeptidase
123
procarboxypepatidase is activated by
trypsin
124
enzymes of the pancreas
pancreatic amylase, pancreatic lipase, ribo/deoxyribonuclease
125
pancreatic amylase digests
starches
126
pancreatic lipase digests
fats
127
ribo/deoxy ribonuclease digests
nucleic acids
128
function of duodenum
receive stomach contents, pancreatic juices, bile, neutralizes stomach acids, fat emulsification, chemical digestion
129
jejunum function
major site of chemical digestion
130
most vascularized part of the small intestine
jejunum
131
ileum
prominent lymphatic nodules resist pathogens
132
plicae circularis
circular folds of mucosa and submucosa that promote the spiral flow of chyme
133
villi
semi-microscopic projections of mucosa that causes the inner-surface of the small intestine to appear fuzzy
134
what does each villi in the small intestine have?
capillaries and lacteal
135
lacteal
lymphatic capillary for fat absorbtion
136
microvilli
small cellular projections attached to enterocytes
137
enterocytes
simple columnar epithelial cells lining the lumen
138
brush border
microvilli of the small intestine form a border on each absorptive cell
139
brush border enzymes are found in
microvilli plasma membrane
140
contact digestion
chyme must contact the brush border for digestion to be completed
141
carbs and amino acids are absorbed into enterocytes via
transport proteins
142
carbs and amino acids diffuse out of enterocytes into
capillaries
143
micelle
droplets of bile acids and fatty acids absorbed into enterocytes
144
fatty acids are transported in
chylomians
145
chylomians
droplets of triglycerides surrounded by phospholipids
146
lipids in the small intestine are absorbed into
lacteals
147
function of large intestines
absorption of water and salts
148
how much reside is received by the large intestine from the small intestine each day
500 mL
149
how much residue is reduced to through absorbtion
150 mL
150
how long does it take to convert residue to feces
36-48 hours
151
defecation
elimination of feces
152
defection exits through
rectum and anal canal
153
vermiform appendix
contains lymphocytes and bacteria, attached to the large intestine
154
epithelium of the mucosa of the large intestine
simple columnar
155
anal canal epithelium
non-keratinzed stratified squamous
156
intestinal crypts
glands extending into the lamina propia
157
intestinal crypts contain
goblet cells that produce mucus
158
taenia coli
three thickened strips of concentrated longitudinal fibers in the muscularis externa
159
haustra
pouches along the large intestine that residue moves through
160
distension of haustrum causes
contraction
161
internal anal sphincter
involuntary smooth muscle that relaxes to release feces
162
mass movement are also known as
bowel movement
163
mass movement
strong contractions of the large intestine 1-3 times a day
164
mass movements are triggered by
gastrocolic and duodenoscopic reflexes
165
gastrocolic reflex
filling of the stomach
166
duodenocolic reflex
filling of the duodendum
167
rectum
distal portion of the large intestine
168
anal columns and sinuses secrete
lubricating mucus
169
stimulation of large intestine
stretch of rectum for defecation
170
intrinsic defecation reflexes
stimulation of the myenteric nerve plexus to contract the rectum m and relax the internal sphincter
171
is the intrinsic defecation reflex strong or weak
weak
172
parasympathetic defecation reflex
spinal cord signals intensify peristalsis and relaxation of anal sphincter
173
is voluntary stimulation required for defecation
yes
174
how many microbes are in the gut
over 800
175
function of the gut microbiome
digest material that enzymes cannot, and help synthesize vitamins B and K
176
flatus
intestinal gas
177
what is flatus made of
swallowed air and bacterial gas
178
flatus odor is caused by
hydrogen sulfide, indole, skatole
