Digestive System Flashcards
1
Q
What is another name for the GI tract?
A
alimentary canal
2
Q
List the main organs in the digestive system
A
mouth, pharynx, esophagus, stomach, small intestine, and large intestine
3
Q
List the accessory digestive organs
A
teeth, tongue, gallbladder, salivary glands, liver, and pancreas
4
Q
In order, what are the main stages in the digestive process?
A
- ingestion
- Mechanical breakdown
- Propulsion
- Digestion
- Absorption
- Defecation
5
Q
Which step in the digestive process are swallowing and peristalsis apart?
A
Propulsion
6
Q
Define peristalsis
A
alting waves of contraction and relaxation
7
Q
Which 3 components constituent mechanical breakdown?
A
chewing, churning, and segmentation
8
Q
What is segmentation?
A
rhythmic local constrictions of small intestine
9
Q
Passage of digested end products from GI tract lumen into blood or lymph
A
Absorption
10
Q
Elimination of indigestible substances
A
Defecation
11
Q
What controls GI tract motility and secretion?
A
Enteric nervous system
12
Q
What provokes digestive activity?
A
mechanical and chemical stimuli
13
Q
When stimulated, receptors in GI tract walls initiate reflexes that…?
A
- activate/inhibit digestive glands
2. stimulate smooth muscle
14
Q
T or F. Controls of digestive activity are both intrinsic and extrinsic
A
True
15
Q
What are the 2 neural mechanisms?
A
- Short reflexes- GI tract
2. Long reflexes- CNS center and ANS fibers
16
Q
Describe hormonal mechanisms.
A
involve hormone-producing cells in stomach and small intestine
17
Q
What covers the abdomen?
A
peritoneum
18
Q
What type of peritoneum covers the organs?
A
visceral peritoneum
19
Q
What comes between visceral and parietal peritoneum?
A
peritoneal cavity
20
Q
What type of peritoneum lines the abdominopelvic cavity?
A
parietal peritoneum
21
Q
What is the double layer of peritoneum that extends to digestive organs from body wall?
A
mesentery
22
Q
What are the 4 layers of the alimentary canal?
A
muscosa, submucosa, muscularis externa, and serosa
23
Q
Which layer of the alimentary canal consist of epithelium, lamina propria, and muscularis externa?
A
Mucosa
24
Q
Dense connective tissue; contains blood vessels, lymphatics, and nerve fibers
A
Submucosa
25
visceral peritoneum
serosa
26
Inner circular layer; outer longitudinal layer
Muscularis externa
27
Bounded by lips, cheeks, palate, and tongue; lines by stratified squamous epithelium
Mouth (oral cavity)
28
Bone in the oral cavity
hard palate
29
Skeletal muscle
soft palate
30
What projects from free edges in the mouth?
uvula
31
Positions food during chewing, mixes food with saliva to form a bolus, initiates swallowing
tongue
32
What are the 3 salivary glands?
parotid gland, submandibular gland, and sublingual glands
33
What are the functions of the saliva?
cleanses mouth, dissolves food chemicals, moistens food, and begins chemical breakdown of starch
34
Between which 2 ages do teeth begin to erupt?
6-24 months
35
How many permanent teeth can one have?
32
36
What are the 4 classes of teeth? Amount upper L or R?
incisors (2), canines (1), premolars (2), and molars (3)
37
What are the 3 main parts of the teeth?
crown, neck, and root
38
Nasopharynx, Oropharynx, and laryngopharynx
Pharynx
39
Which organ is lined by the stratified squamous epithelium?
esophagus
40
Which digestive processes occur in the mouth?
ingestion, mechanical breakdown, propulsion, and digestion
41
Which digestive process occur in the pharynx and esophagus?
propulsion
42
How does mastication occur?
Cheeks and lips hold food between teeth, teeth cut and grind, and tongue from a bolus
43
How does deglutition occur?
tongue presses against hard palate and bolus is forced into oropharynx
44
Wha are the 2 phases in delglutition? voluntary?
Buccal phase- voluntary
Paryngeal-Esophageal Phase- Involuntary
45
What moves food through esophagus?
Peristalsis
46
What are the functions of the stomach?
temporary food storage (50mL/4L), begins chemical breakdown of proteins, and converts bolus to chyme
47
What controls food entry into the duodenum?
pyloric sphincter
48
What is the extra layer in the stomach?
oblique layer
49
In the stomach, where are gastric pits located?
mucosa
50
How are gastric juices produces?
gastric pits lead into gastric glands
51
What are the 4 major cells types in the gastric gland?
mucous neck cells, parietal cells, chief cells, and enteroendocrine cells
52
Required for absorption of vitamin B12
intrinsic factor
53
Secrete mucus
mucous neck cells
54
Secretes HCl and intrinsic factor, activate pepsin
Parietal cells
55
Secrete pepsinogen
chief cells
56
Secrete gastrin
enteroendocrine cells
57
Protects stomach mucosa, created by thick layer of bicarbonate-rich mucus
mucosal barrier
58
In mechanical breakdown, bolus is converted into..?
chyme
59
In Digestion, what is the purpose of HCl and pepsin?
HCl- denatures proteins
Pepsin- begins digestion of proteins
60
In propulsion, where is chyme delivered?
small intestines
61
In L, how much gastric juices is secreted per day?
3L
62
What regulates secretion?
long and short reflexes and hormones
63
What are the 3 phases of the gastric secretion?
cephalic, gastric, and intestinal
64
When does the cephalic phase occur?
Before food enters the stomach
65
What triggers the cephalic phase?
triggered by smell, taste, sight or thought
66
Which nerve stimulates the enteric neurons?
vagus causing secretion
67
When does the gastric phase occur?
once food reaches the stomach
68
How much gastric juice is the in the stomach?
2/3
69
What provoked the gastric phase?
distension of short and long reflexes, peptides and rising pH stimulate gastrin
70
When does the intestinal phase occur?
Once food enters the duodenum
71
How is the intestinal phase inhibited?
enterogastric reflex and release of intestinal hormones
72
What provokes the intestinal phase?
distension of duodenum, presence of fats, and acidic chyme
73
What is inhibited to promote gastric secretion?
Enteric neurons and vagus nerves
74
Which 2 hormones are secreted by intestinal hormones?
cholecystokinin and secretin
75
In gastric contractile activity what happen to chyme?
3 ml into dudoenum and 27mL forced back into stomach
76
Where does the small intestine begin or end?
begins at pyloric sphincter and ends at ileocecal valve
77
From proximal to distal what are the parts of the small intestine?
duodenum, jejunum, and ileum
78
Where are the bile duct and main pancreatic duct located?
Bile duct: from liver
Main pancreatic duct: pancreas unite in wall of duodenum
79
What controls entry of bile and pancreatic juice?
Hepatopancreatic sphincter
80
What are the 3 structural modifications in the small intestine?
circular folds, villi, microvilli
81
What is the function of the 3 structural modifications in the small intestine?
increase surface area for absorption
82
What forms the circular folds? Purpose
Formed by mucosa and submucosa.
Forces chyme ti slowly spiral through lumen
83
Fingerlike projections of mucosa and contain capillary beds and lacteals
Villi
84
Form brush border and brush border enzymes
microvilli
85
What do the pits of the villi lead?
intestinal crypts
86
Secretory cells
intestinal juice
87
lymphoid nodules in mucosa of ilium
peyer's patches
88
submucosa of duodenum, secrete alkaline in mucus
dudodenal glands
89
Produces bile
liver
90
stores and concentrates bile
gallbladder
91
Drains lover
common hepatic duct
92
drains gallbladder
cystic duct
93
What is formed by union of common hepatic and cystic ducts?
bile ducts
94
What are the 3 parts of the portal triad?
Hepatic artery, hepatic portal vein, and bile duct
95
Carries blood from digestive organs to liver for processing
hepatic portal vein
96
Oxygen-rich arterial blood in the liver
hepatic artery
97
Nutrient-rich venous blood in the liver
hepatic portal vein
98
Runs between hepatocyte platesq
liver sinusoids
99
What is the flow of blood in the liver?
hepatic artery and hepatic portal vein -> liver sinuoids-> central vein
100
Remove bacteria worn-out RBCs, and other debris from blood as flows past
Kupffer cells/ Stellate macrophages
101
Produce bile, process bloodbome nutrients, store fat-soluble vitamins and plays important role in detoxification
Hepatocyte
102
Secreted bile flows through what toward bile ducts?
bile canaliculi
103
Yellow-green alkaline solution
bile
104
cholesterol derivatives that function to emulsify fats
bile salts
105
bilirubin
chief bile pigment
106
Where in the pancreas do the exocrine functions occur?
acinar cells
107
How does the pancreatic juice enter the dudoenum
pancreatic duct
108
What are the 3 components pancreatic juice?
water, digestive enzymes, and bicarbonate ions
109
What causes the gallbladder to contract, stimulate secretion of enzyme-rich pancreatic juice and relaxes hepatopancreatic juice
CCK
110
stimulates secretion of bicarbonate-rich pancreatic rich
secretin
111
What digestive processes occur in the small intestine?
Mechanical breakdown and propulsion: segmentation and peristalsis
Digestion: enzymes from pancreas; brush border enzymes of microvilli
Absorption: Most water and virtually all nutrients absorbed
112
List what optimal digestive activity depends on:
1. bile from liver and gallbladder
2. Digestive enzymes from pancreas
3. Bicarbonate ions from the pancreas
4. Slow, measured delivery of chyme from stomach
113
Most common motion of small intestine, mixes chyme with bile, pancreatic juice, and intestinal juice, moves ileocecal valve
Segmentation
114
Begins late in intestinal phase
migrating motor complex
115
Which 2 mechanisms increase motility of ileum and cause ileocecal sphincter to relax?
Gastroileal reflex and gastrin released by stomach
116
Three bands of smooth muscle
teniae coli
117
Pocket-like sacs in wall of large intestine
Haustra
118
From small intestine to the anal canal where does the food go?
cecum, ascending colon, transverse colon, descending colon, sigmoid colon
119
List the subdivisions of the large intestine
cecum, appendix, colon, rectum, and ana canal
120
What are the 3 sphincters in the anus? Type of muscle?
Internal anal sphincter (smooth muscle) and external anal sphincter (skeletal muscle)
121
What type of epithelium is the large intestine? Anal Canal?
Large intestine: simple columnar epithelium
Anal canal: stratified squamous
122
What type of cells do large intestines contains that secrete mucus?
Goblet cells
123
What are the functions of the Bacterial flora in the large intestine?
colonize colo, ferment cellulose and other plant polysaccarides, synthesize B complex vitamins and vitamin K
124
What are the digestive process in the large intestine?
absorption- absorbs remaining water
Propulsion- propels feces toward rectum
Defacation- eliminates feces toward body
125
Long, slow-moving, powerful contractile waves, force contents toward rectum
Mass movements
126
Parasympathetic reflex that is initiated by stretching rectal wall.
Defecation reflex
127
What is the result of the defecation reflex
sigmoid colon and rectum contract and internal anal sphincter relaxes
128
What is the equation of the teeth?
(2I,1C,2PM,3M/21,1C,2PM,3M) x 2
