Digestive System Flashcards
(126 cards)
1
Q
provides the nutrients cells need for maintenance and growth
A
digestive system
2
Q
muscular tube in the digestive system lined by a mucous epithelium also known as the gastrointestinal tract
A
digestive tract
3
Q
name the accessory organs of the digestive system
A
- salivary glands
- liver
- gallbladder
- pancreas
4
Q
the longest segment of the digestive tract
A
small intestine
5
Q
a double sheet of peritoneal membrane that stabilizes the positions of the attached organs and prevent the intestines from becoming entangled during digestive movements or sudden changes in body position
A
mesentery
6
Q
name the 2 layers of the mesentery
A
- mesothelium
- areolar tissue
7
Q
name the major layers of the digestive tract
A
- mucosa
- submucosa
- muscularis externa
- serosa
8
Q
inner lining of the digestive tract that is moisten by glandular secretions and a lamina propia of areolar tissue
A
mucosa
9
Q
a layer of dense irregular connective tissue that surrounds the mucosa and contains exocrine glands that secrete buffers and enzymes into the lumen of the digestive tract
A
submucosa
10
Q
smooth muscle cells that contains two layers that play an essential role in mechanical processing and in the movement of materials along the digestive tract
A
muscularis externa
11
Q
name the two layers of the muscularis externa
A
- inner circular layer
- outer longitudinal layer
12
Q
a layer of visceral peritoneum that covers the muscularis externa
A
serosa
13
Q
a part of the serosa that firmly attaches the digestive tract to adjacent structures
A
adventitia
14
Q
permanent transvers folds in the intestinal lining
A
plicae circulares
15
Q
name the 3 components of the mucosa
A
- villi
- lamina propia
- muscularis mucosae
16
Q
small mucosal projections that stick into the lumen of the small intestine, and also increases the surface are available for absorption
A
villi
17
Q
consists of a layer of areolar tissue
A
lamina propria
18
Q
consists of two concentric layers of smooth muscle whose contractions alter the shape of the lumen and move the plicae and villi
A
muscularis mucosae
19
Q
name the two layers of the muscularis mucosae
A
- circular muscle layer
- longitudinal muscle layer
20
Q
the inner layer of the muscularis mucosae that encircles the lumen
A
circular muscle layer
21
Q
the outer layer of the muscularis mucosae that contains muscle cells oriented parallel to the long axis of the tract
A
longitudinal muscle layer
22
Q
a nerve network that contains sensory neurons, parasympathetic ganglionic neurons, and sympathetic postganglionic fibers that innervate the mucosa and submucosa
A
submucosal plexus
23
Q
a network of parasympathetic neurons, interneurons, and sympathetic postganglionic fibers that lies between the circular and longitudinal muscle layers
A
myenteric plexus
24
Q
regulates movement of materials along internal passageways of the digestive tract and mechanical processing, lacks myofibrils and sacomeres, does not contain striations (nonstriated muscle)
A
smooth muscle
25
name the two types of smooth muscle in the digestive tract
- multi-unit smooth muscle
| - visceral smooth muscle
26
increases muscle tone and activity in the digestive system
parasympathetic nerves
27
promotes muscular inhibition and relaxation in the digestive system; inhibits digestion
sympathetic nerves
28
mechanical processing; cycles of contraction that churn and fragment the bolus, mixing the contents with intestinal secretions
segmentation
29
contractions that propel materials from one portion of the digestive tract to another; moving materials along the digestive tract; a wave of contraction in the circular muscles that forces the bolus forward
peristalsis
30
name the 3 major mechanisms that regulate and control the digestive activities
- local factors
- neural control mechanisms
- hormonal control mechanisms
31
a reflex that is responsible for the wave of peristalsis moving along the intestine and that involves contraction of the digestive tube above and relaxation below the place where it is stimulated by an accumulated mass of food
myenteric reflex
32
stimuli for digestive activities, such as changes in pH or distortion of the intestinal lumen
local factors
33
involves myenteric reflexes
neural mechanisms
34
involves neuroendocrine cells
hormonal mechanisms
35
endocrine cells in the epithelium of the digestive tract
enteroendocrine cells
36
contains the tongue, salivary glands, and teeth, and receives secretions of the salivary glands; lined by the oral mucosa
oral cavity
37
what are the two movements of the digestive system
- mixing food
| - propelling food forward through the system
38
physically grinding and mixing w saliva
mastication
39
layer of the muscularis externa that squeezes closed like a sphincter
inner circular fibers
40
layer of muscularis externa that shortens
outer longitudinal fibers
41
name the 2 functions of the digestive system
- digestion
| - absorption
42
transport of digested nutrients into blood stream
absorption
43
breaking down of food
digestion
44
palate used for mastication
hard palate
45
palate used for swallowing
soft palate
46
covers the nasal cavity during swallowing
uvula
47
name the 4 different types of teeth
- incisors
- cuspids
- bicuspids
- molars
48
hardest structures in the body; not considered bones because they have two proteins not found in bones and their structure is different
teeth
49
what two things play a key role in swallowing
- pharynx
| - esophagus
50
an anatomical space that serves as a common passageway for solid food, liquids, and air
pharynx
51
a hollow muscular tube that conveys solid food and liquids to the stomach; the structure connecting the pharynx to the stomach
esophagus
52
connective tissue outside of the muscularis externa that anchors the esophagus to the posterior body wall
adventitia
53
a complex process that can be initiated voluntarily but proceeds automatically once it begins; swallowing
deglutition
54
name the 3 parts of the pharynx
- nasopharynx
- oropharynx
- laryngopharynx
55
part of pharynx that connects the nasal cavity to back of mouth
nasopharynx
56
part of pharynx that located at the back of the mouth
oropharynx
57
part of pharynx that is below the mouth to the larynx
laryngopharynx
58
name the 3 stages of deglutition
- buccal phase
- pharyngeal phase
- esophageal phase
59
voluntary phase of deglutition where food is formed into a bolus and the tongue pushes the bolus to the back of the mouth
buccal phase
60
the bolus contacts the palatal arches and moves into the esophagus
pharyngeal phase
61
swallowing begins as pharyngeal muscles contract and the bolus is moved toward the stomach via peristaltic
esophageal phase
62
prevents the backflow of materials from the stomach into the esophagus; closes opening to stomach
lower esophageal sphincter
63
what 2 ways can the serous membrane be divided
- visceral peritoneum
| - parietal peritoneum
64
a ventral body cavity lined by a serous membrane called the peritoneum
peritoneal cavity
65
serosa that covers organs within the peritoneal cavity
visceral peritoneum
66
lines the inner surfaces of the body wall
parietal peritoneum
67
a muscular, expandable, J-shaped organ with three layers in the muscularis externa
stomach
68
name the 4 regions of the stomach
- cardia
- fundus
- body
- pylorus
69
secrete most of the acid and enzymes involved in gastric digestion and located in the fundus and body
gastric gland
70
secrete intrinsic factor and hydrochloric acid
parietal cells
71
a glycoprotein that facilitates the absorption of vitaminB12 across the intestinal lining; required for absorption of B12 vitamins
intrinsic factor
72
secrete pepsinogen
chief cells
73
a sudden influx of bicarbonate ions into the bloodstream from active parietal cells; it causes a temporary increase in blood pH
alkaline tide
74
protects epithelial cells against the acid and enzymes in the gastric lumen
alkaline mucous layer
75
specialized for the absorption of nutrients
intestinal tract
76
capillaries that carry absorbed nutrients to the hepatic portal circulation for delivery to the liver, which adjusts the nutrient concentrations in blood before the blood reaches the general systemic circulation
lamina propria
77
lymphatic capillaries in the intestinal villi that transport absorbed fatty acids that cannot enter blood capillaries
lacteal
78
plays the key role in the digestion and absorption of nutrients
small intestines
79
name the 3 regions of the small intestines
- duodenum
- jejunum
- ileum
80
region of small intestine that receives chime from the stomach and neutralize its acids to avoid damaging the absorptive surfaces of the remaining regions of the small intestines
duodenum
81
begins to break down proteins
pepsin
82
acid that converts pepsinogen to pepsin
hydrochloric acid
83
breaks down lipids
lipase
84
name the 5 hormones that are involved in the regulation of digestive activities
- gastrin
- secretin
- gastric inhibitory peptide (GIP)
- cholecystokinin (CCK)
- vasoactive intestinal peptide (VIP)
85
secreted by G cells in the pyloric antrum and enteroendocrine cells in the duodenum. promotes increased stomach motility and stimulating the production of gastric acids and enzymes
gastrin
86
released when chime arrives in the duodenum; reduces gastric motility and secretory rates. primary effect is an increase in the secretion of bile (by the liver) and buffers ( by the pancreas) which in turn act to increase the pH of the chyme
secretin
87
secreted when fats and carbohydrates enter the small intestine; stimulates duodenal gland activity, stimulates lipid synthesis in adipose tissue, and increasing glucose use by skeletal muscles
gastric inhibitory peptide (GIP)
88
secreted when chime arrives in the duodenum. it increases the secretion of pancreatic enzymes and push pancreatic secretions and bile into the duodenum. inhibits gastric activity, and it appears to have CNS effect that reduce the sensation of hunger
cholecystokinin (CCK)
89
stimulates the secretion of intestinal glands, dilates regional capillaries, and inhibits acid production in the stomach. it provides an efficient mechanism for removing absorbed nutrients
vasoactive intestinal peptide (VIP)
90
name the 3 phases of secretion
- cephalic phase
- gastric phase
- intestinal phase
91
begins when you see, smell, taste, or think of food. directed by the CNS and triggers the parasympathetic reflexes; prepares the stomach to receive food
cephalic phase
92
begins with the arrival of food in the stomach and builds on the stimulation provided during the cephalic phase. during this period, gastrin stimulates contractions in the muscularis externa of the stomach and intestinal tract
gastric phase
93
begins when chime first enters the small intestine, it controls the rate of gastric emptying to ensure that the secretory, digestive, and absorptive functions of the small intestine can proceed with reasonable efficiency; controls the rate of gastric emptying
intestinal phase
94
inhibits both gastrin production and gastric contractions and stimulates the contraction of the pyloric sphincter, which prevents further discharge of chyme
enterogastric reflex
95
name the two central reflexes triggered by stimulation of the stretch receptors in the stomach wall
- gastroenteric reflex
| - gastroileal reflex
96
stimulates motility and secretion along the entire small intestine
gastroenteric reflex
97
triggers the opening of the ileocecal valve, allowing materials to pass from the small intestine into the large intestine
gastroileal reflex
98
functions include the reabsorption of water and the compaction of the intestinal contents into feces, the absorption of important vitamins liberated by bacterial action, and the storage of fecal material prior to defecation. consist of the cecum, the colon, and the rectum
large intestine
99
name the 4 regions of the colon
- ascending colon
- descending colon
- sigmoid colon
- transverse colon
100
the exit of the anal canal
anus
101
lubricate and moisten the mouth and initiate the digestion of complex carbohydrates; secretes saliva
salivary glands
102
a mixture of glandular secretions in the mouth; a mixture of serous and mucous
saliva
103
name the 3 pairs of salivary glands
- sublingual salivary glands
- submandibular salivary glands
- parotid salivary glands
104
salivary gland that produce secretion that acts as a buffer and lubricant
sublingual salivary glands
105
salivary gland that secretes a mixture of buffers, mucins, and a salivary amylase. transport antibodies into the saliva, to provide additional protection against pathogens in food
submandibular salivary glands
106
an enzyme that break down complex starches (complex carbohydrates)
salivary amylase
107
drains the secretions of the parotid salivary gland and empties them into the vestibule at the level of the second upper molar
parotid duct
108
salivary gland that produce a secretion containing large amounts of salivary amylase
parotid salivary glands
109
secrete mucins, water, and buffers
mucous cells
110
secrete salivary amylase and lysozyme; transport antibodies from the interstitial fluid into the saliva
serous cells
111
the largest internal organ and where bile is produced
liver
112
produces bile which emulsifies lipids into smaller droplets
lipid metabolism
113
deaminating amino acids, forming urea, synthesizing plasma proteins and clotting factors
protein metabolism
114
stores bile produced by the liver and releases it into the small intestine
gallbladder
115
name the 3 regions of the gallbladder
- fundus
- body
- neck
116
provides several digestive enzymes necessary for the breakdown of starches, lipids, nucleic acids, and proteins
pancreas
117
begins carbohydrate digestion by breaking down starch and glycogen to disaccharides
salivary amylase
118
begins protein digestion
pepsin
119
begins butterfat digestion
gastric lipase
120
breaks down starch and glycogen into disaccharides
pancreatic amylase
121
breaks down fats into fatty acids and glycerol
pancreatic lipase
122
breaks down peptides into amino acids
carboxypeptidase
123
breaks down nucleic acids into nucleotides
nucleases
124
breaks down peptides into amino acids
peptidase
125
breaks down fats into fatty acids and glycerol
intestinal lipase
126
shortens trypsinogen into trypsin
enterokinase
