Digestive System Flashcards
1
Q
consists of
a group of organs that break down the food we eat into smaller
molecules that can be used by body cells
A
digestive system
2
Q
a continuous tube that extends
through the thoracic and abdominal cavities from the esophagus to the anus through the thoracic and abdominopelvic
cavities
A
digestive canal
3
Q
Organs of the digestive canal
A
esophagus,
stomach, small intestine, large intestine, and anal canal.
4
Q
sustained contraction
A
tonus
5
Q
accessory digestive organs
A
mouth teeth, tongue, salivary glands,
pharynx, liver, gallbladder, and pancreas
6
Q
digestive system performs six basic processes
A
ingestion, secretion, motility,
digestion, absorption, and defecation
7
Q
process involves taking foods and liquids
into the mouth (eating).
A
Ingestion
8
Q
release of water,
acid, buffers, and enzymes
into lumen of digestive canal.
A
Secretion
9
Q
capability of the digestive canal to mix and move material
along its length
A
Motility
10
Q
the process of breaking down
ingested food into small molecules that can be used by
body cells
A
Digestion
11
Q
large carbohydrate,
lipid, protein, and nucleic acid molecules in food are split
into smaller molecules by hydrolysis
A
Chemical digestion
12
Q
Digestive enzymes produced by the salivary glands,
tongue, stomach, pancreas, and small intestine catalyze
A
catabolic reactions
13
Q
The movement of the products of digestion
from the lumen of the digestive canal into blood plasma or
lymph plasma
A
absorption
14
Q
elimination of
feces from digestive canal
A
Defecation
15
Q
Layers of the Digestive
Canal
A
mucosa, submucosa, muscular layer, serosa/adventitia
16
Q
inner lining of the digestive canal, is a mucous
membrane
A
mucosa
17
Q
epithelium in the mouth, pharynx, esophagus, and anal
canal
A
nonkeratinized stratified squamous epithelium
18
Q
Epithelium in the stomach and intestines
A
Simple columnar epithelium
19
Q
Endocrine cells located among the epithelial cells that secretes hormones
A
enteroendocrine cells
20
Q
areolar connective tissue containing many
blood and lymphatic vessels, which are the routes
by which nutrients absorbed into the digestive canal
reach the other tissues of the body; binds the epithelium to the muscularis mucosae
A
Lamina propria
21
Q
also contains the
majority of the cells of the mucosa-associated lymphoid tissue (MALT); commonly found in the tonsils, SI, appendix, and LI
A
Lamina propria
22
Q
Thin layer of smooth muscle fibers that throws the mucous membrane
of the stomach and small intestine into many small folds
A
muscularis mucosae
23
Q
3 layers of the mucosa
A
epithelium, lamina propria, and muscularis mucosae
24
Q
consists of areolar connective tissue that binds
the mucosa to the muscularis; contains the submucosal neural plexus
A
submucosa
25
Contains the myenteric neural plexus
Muscular layer
26
Those portions of the digestive canal that are suspended in the
abdominal cavity have a superficial layer called
Serosa
27
Composition of serosa
areolar connective tissue and simple squamous epithelium
(mesothelium)
28
adventitia is present in
esophagus
29
The neurons are arranged into two neural plexuses: the
myenteric neural plexus and submucosal neural plexus
Enteric nervous system
30
plexus of Auerbach
myenteric neural plexus
31
plexus of Meissner
submucosal neural plexus
32
The plexuses of the ENS
consist of
motor neurons, interneurons, and sensory neurons
33
motor neurons of ___ supply the longitudinal and circular smooth muscle
layers of the muscular layer, this neural plexus mostly controls
digestive canal motility (movement), particularly the frequency
and strength of contraction of the muscular layer.
myenteric neural plexus
34
The motor
neurons of the ___ supply the secretory
cells of the mucosal epithelium, controlling the secretions of the
organs of the digestive canal.
submucosal neural plexus
35
connect the neurons of the myenteric and submucosal neural
plexuses
interneurons of the ENS
36
activated when food distends (stretches) the wall of a
digestive canal organ
mechanoreceptors, such as stretch receptors
37
nerves supply of parasympathetic
fibers
vagus (X) : most parts of the digestive canal
parasympathetic fibers from the sacral spinal cord: last half of the large intestine
38
nerves that innervate the digestive canal causes an increase in digestive canal secretion and
motility by increasing the activity of ENS neurons
parasympathetic nerves
39
nerves that supply the digestive canal arise
from the thoracic and upper lumbar regions of the spinal cord.
Sympathetic nerves
40
cause a
decrease in digestive canal secretion and motility by inhibiting
the neurons of the ENS. Emotion
sympathetic nerves
41
the peritoneal cavity may become distended by the
accumulation of several liters of fluid
ascites
42
organs lie on the posterior
abdominal wall and are covered by peritoneum only on their
anterior surfaces; they are not in the peritoneal cavity
retroperitoneal
43
kidneys, ascending and descending
colons of the large intestine, duodenum of the small intestine,
and pancreas
retroperitoneal
44
five major peritoneal folds
greater omentum, falciform ligament, lesser omentum,
mesentery, and mesocolon
45
the longest
peritoneal fold, drapes over the transverse colon and coils
of the small intestine like a “fatty apron”
greater omentum
46
“beer belly;" many lymph nodes
greater omentum
47
attaches the liver to the anterior abdominal wall and diaphragm
falciform ligament
48
arises as an anterior fold in the serosa of the stomach and duodenum, and it connects the stomach and duodenum to the liver
lesser omentum
49
pathway for blood vessels entering the liver and contains the hepatic portal vein, common hepatic artery, and
bile duct, along with some lymph nodes
lesser omentum
50
fan-shaped fold of the peritoneum, that binds the jejunum and
ileum of the small intestine to the posterior abdominal
wall
mesentery
51
Two separate folds of peritoneum; bind the transverse colon (transverse
mesocolon) and sigmoid colon (sigmoid mesocolon) of
the large intestine to the posterior abdominal wall
mesocolon
52
an acute
inflammation of the peritoneum, is contamination of the peritoneum by infectious microbes, which can result from accidental
or surgical wounds in the abdominal wall, or from perforation or
rupture of microbe–containing abdominal organs.
peritonitis
53
formed by the lips, cheeks, hard and soft palates,
oral cavity, teeth, salivary glands, and tongue
mouth
54
lateral walls of the mouth
cheeks
55
are fleshy folds surrounding the opening of the mouth. They contain the orbicularis oris muscle and are covered externally by skin and
internally by a mucous membrane.
lips or labia
56
inner surface of each
lip is attached to its corresponding gum by a midline fold of
mucous membrane called the
labial frenulum
57
space that extends from the lips and
teeth to the fauces and is divided into an oral vestibule and an
oral cavity proper
oral cavity
58
space bounded externally by the cheeks
and lips and internally by the gums and teeth.
oral vestibule
59
space that extends from the gums and teeth to
the fauces
oral cavity
proper
60
the opening between the oral
cavity proper and the oropharynx (throat)
fauces
61
wall or septum that separates the oral cavity from the nasal cavity, and forms the roof of the mouth.v
palate
62
the anterior portion of the
roof of the mouth—is formed by the maxillae and palatine
bones and is covered by a mucous membrane; it forms a bony
partition between the oral and nasal cavities
hard palate
63
posterior portion of the roof of the mouth; an arch-shaped muscular partition between the oropharynx
and nasopharynx that is lined with mucous membrane.
soft palate
64
Hanging from the free border of the soft palate is a fingerlike
muscular structure called
Uvula
65
major salivary
glands
parotid glands, submandibular glands, sublingual glands
66
lubricates and dissolves foods and begins the chemical breakdown of
carbohydrates and lipids.
saliva
67
consist mostly of serous acini (serous fluid–
secreting portions of gland) and a few mucous acini (mucus-secreting portions of gland)
submandibular glands
68
consist of serous acini only
parotid glands
69
consist of mostly mucous acini and a few serous acini
sublingual glands
70
Enzyme that starts the
breakdown of starch in the mouth into maltose, maltotriose,
and α-dextrin
salivary amylase
71
secretion of saliva; is controlled by the autonomic nervous system
salivation
72
Amounts of saliva secreted daily
1000–1500 mL (1–1.6 qt).
73
an inflammation and enlargement of the parotid glands accompanied by moderate fever, malaise (general discomfort), and extreme pain in the throat, especially when swallowing sour foods or acidic juices; it is due to paramyxovirus
mumps
74
nerves stimulate the secretion of saliva
facial (VII) and glossopharyngeal (IX) nerves
75
accessory digestive organ composed of skeletal muscle covered with mucous membrane.
tongue
76
move the tongue from side to side and in and out to maneuver food for chewing, shape the food into a rounded mass, and force the food to the back of the mouth for swallowing. They also form the floor of the mouth and hold the tongue in position
extrinsic muscles of the tongue
77
They alter the shape and size of the tongue for speech and swallowing.
intrinsic muscles of the tongue
78
a fold of mucous membrane in the midline of the undersurface of the tongue, is attached to the floor of the mouth and aids in limiting the movement of the tongue posteriorly
lingual frenulum
79
“tongue-tied”
ankyloglossia
80
The dorsum (upper surface) and lateral surfaces of the tongue are covered with projections of the lamina propria covered
with stratified squamous epithelium
lingual papillae
81
the receptors for gustation (taste) in taste buds
gustatory epithelial cells
82
Lingual glands
lingual lipase
83
are accessory digestive organs located in dental alveoli (sockets) of the alveolar processes of the mandible and maxillae.
teeth/ dentes
84
The alveolar processes
(thickened ridges) are covered by the
gingivae
85
consists of skeletal muscle; regulates the movement of food from the pharynx into the esophagus
upper esophageal sphincter
86
consists of smooth muscle and is near the heart; regulates the movement of food from the esophagus into the stomach
lower esophageal sphincter
87
movement of food from the mouth into the stomach is achieved by the act of __ or swallowing
deglutition
88
Three stages of swallowing
voluntary stage, pharyngeal stage, esophageal stage
89
Swallowing starts when the bolus is forced to the back of
the oral cavity and into the oropharynx by the movement of
the tongue upward and backward against the palate
voluntary stage
90
involuntary passage of the bolus through
the pharynx into the esophagus
pharyngeal stage
91
The bolus stimulates receptors in the oropharynx, which send impulses to the
deglutition center of the medulla
92
involuntary passage of the bolus through the esophagus into the stomach
esophageal stage
93
progression of coordinated contractions and relaxations of the circular and longitudinal layers of the muscular layer, pushes the bolus on
peristalsis
94
If the lower esophageal sphincter fails to close adequately after food has entered the stomach, the stomach contents can reflux
(back up) into the inferior portion of the esophagus.
Gastroesophageal reflux Disease
95
J-shaped enlargement of the digestive canal
directly inferior to the diaphragm in the abdomen; connecting the esophagus and the duodenum
stomach
96
Mixes saliva, food, and gastric juice to form a soupy liquid called chyme
stomach
97
Secretes gastric juice, which contains HCI (kills bacteria and denatures proteins), pepsin (begins the digestion of proteins), intrinsic factor (aids absorption of vitamin B12), and gastric lipase (aids digestion of triglycerides). Secretes gastrin into blood
stomach
98
The medical specialty that deals with the structure, function, diagnosis, and treatment of diseases of the stomach and intestines is called
gastroenterology
99
stomach has four main regions
cardia, fundus, body, pyloric
100
part of the stomach that surrounds
the opening of the esophagus into the stomach
cardia
101
The rounded portion superior to and to the left of the cardia
fundus
102
Inferior to the fundus is the large central portion of the stomach
body
103
first part of the pyloric that connects to the
body of the stomach
pyloric antrum
104
The second region that leads to the third region
pyloric canal
105
third part which in turn connects to the duodenum.
pylorus
106
the smooth muscle fibers of the sphincter fail to relax normally, so food does not pass easily
from the stomach to the small intestine, the stomach becomes overly full, and the infant vomits often to relieve the pressure
pylorospasm
107
narrowing of the pyloric sphincter that must be corrected surgically
pyloric stenosis
108
The surface of the mucosa is a layer of simple columnar epithelial cells called
surface mucous cells
109
combined secretions of mucous cells, parietal cells, and chief cells.
gastric juice
110
Epithelial cells extend down into the lamina propria, where they form columns of secretory cells called
gastric glands
111
Several gastric glands open into the bottom of narrow channels called
gastric pits
112
The gastric glands contain three types of exocrine gland cells that secrete their products into the stomach lumen:
parietal, mucous, chief cells
113
Each peristaltic wave moves gastric contents from the body of the stomach down into the antrum
propulsion
114
Because most food particles in the stomach
initially are too large to fit through the narrow pyloric sphincter, they are forced back into the body of the stomach, a process referred to as
retropulsion
115
Once the food particles in chyme are small enough, they can pass through the pyloric sphincter, a phenomenon known as
gastric emptying
116
The only proteolytic (protein-digesting)
enzyme in the stomach is (pH 2)
pepsin
117
Another enzyme of the stomach, which
splits triglycerides (fats and oils) in fat molecules (such as those found in milk) into fatty acids and monoglycerides (pH of 5–6).
gastric lipase
118
Secrete intrinsic factor; Needed for absorption of vitamin B12 (used in red blood cell formation, or erythropoiesis).
parietal cells
119
Secrete hydrochloric acid; Kills microbes in food; denatures proteins; converts
pepsinogen into pepsin
chief cells
120
Secrete pepsinogen; Pepsin (activated form) breaks down proteins into peptides.
chief cells
121
Secrete gastric lipase; Splits triglycerides into fatty acids and monoglycerides
chief cells
122
Secrete gastrin; Stimulates parietal cells to
secrete HCl and chief cells to secrete pepsinogen; contracts lower esophageal sphincter, increases motility of stomach,
and relaxes pyloric sphincter
G cells
123
Regulates passage of chyme from stomach to duodenum; prevents backflow of chyme
from duodenum to stomach.
pyloric sphincter
124
also known as emesis is the forcible expulsion of the contents of the upper digestive canal (stomach and sometimes duodenum)
through the mouth.
vomiting
125
digest starches (polysaccharides), proteins, triglycerides, and nucleic acids
pancreatic enzymes
126
retroperitoneal gland; lies posterior to the greater curvature of the stomach.
pancreas
127
Larger of the two ducts. In most people, the pancreatic duct joins the bile duct from the liver and gallbladder and enters the duodenum as a dilated common duct called the hepatopancreatic ampulla
pancreatic duct, or duct of Wirsung
128
The ampulla opens on an elevation of the duodenal mucosa known as the
major duodenal papilla
129
The passage of pancreatic juice and bile through the hepatopancreatic ampulla into the duodenum of the small intestine is regulated by a mass of smooth muscle surrounding the ampulla known as the
sphincter of the hepatopancreatic ampulla, or sphincter of Oddi
130
Leads from the pancreas and empties into the duodenum about 2.5 cm (1 in.) superior to the hepatopancreatic ampulla
accessory duct (duct of Santorini),
131
About 99% of the clusters, constitute the exocrine portion of the organ; The cells within pancreatic acini secrete a mixture of fluid and digestive enzymes called pancreatic juice
Pancreatic acini
132
The remaining 1% of the clusters, form the endocrine portion of the pancreas. These cells secrete the hormones glucagon, insulin, somatostatin, and pancreatic polypeptide
pancreatic islets
133
what activates the trypsinogen
enterokinase
134
Inflammation of the pancreas, as may occur in association with alcohol abuse or chronic gallstones
pancreatitis
135
The liver receives oxygenated blood via
hepatic artery
136
The liver receives nutrient-rich deoxygenated blood via
hepatic portal vein
137
a yellow, brownish, or olive-green liquid. It has a pH of 7.6–8.6 and consists mostly of water, bile salts, cholesterol, a phospholipid called lecithin, bile pigments, and several ions.
bile
138
gives feces their normal brown color
stercobilin
139
Bile salts, which are sodium salts and potassium salts of bile acids (mostly chenodeoxycholic acid and cholic acid), play a role in the breakdown of large lipid globules into a suspension of small lipid globules
emulsification
140
Absorbs about 90% of nutrients and water that pass through digestive system
small intestine
141
increase the surface area of the small
intestine for digestion and absorption
Circular folds, intestinal villi, and microvilli
142
secrete lysozyme, a bactericidal enzyme, and are capable of phagocytosis. Paneth cells
may have a role in regulating the microbial population in the small intestine.
Paneth cells
143
Three types of enteroendocrine cells are
found in the intestinal glands of the small intestine
S cells,CCK cells, and K cells
144
secrete an alkaline mucus that helps neutralize gastric acid in the chyme
duodenal glands, also called Brunner’s glands
145
clear yellow fluid, is secreted each day. Intestinal juice contains water and mucus and is slightly alkaline (pH 7.6). The alkaline pH of
intestinal juice is due to its high concentration of bicarbonate ions (HCO3−)
intestinal juice
146
The absorptive cells of the small intestine synthesize several digestive enzymes, called
microvillous-border enzymes
147
localized, mixing contractions that occur in
portions of intestine distended by a large volume of chyme
segmentation
148
Secrete secretin
S cells
149
secrete cholecystokinin
CCK cells
150
Secrete glucose- dependent insulinotropic peptide.
K cells
151
Intensifies peristalsis in the ileum and forces any chyme into the cecum.
gastroileal reflex
152
