Digestive System Flashcards
1
Q
Identify the alimentary canal organs of the digestive system and there function
A
- digest foods and absorbs fragments
mouth, pharynx, esophagus, stomach, small intestines, large intestines
2
Q
identify the 4 accessory organs of the gi system
A
teeth
tongue
gallbladder
digestive glands ( salivary, liver, pancreas)
3
Q
What are the 6 main process of digestion
A
1) ingestion: taking in food
2) propulsion: moving food through the system
3) Mechanical breakdown: chewing, stomach
4) Digestion: stomach and small intestines
5) Absorption: small intestine to lymph vessels
6) Defecation: releasing indigestible food
4
Q
What type of epithelium lines the lumen and what is its function
A
surrounded by mucosa secretes mucus, some enzymes and hormones innermost layer non-keratinized squamous globet cells secrete mucus
5
Q
What type of tissue lines the submucosa
A
connective tissue
6
Q
What type of epithelium line the muscularis and what is its function
A
two layers of smooth muscles
inner layer has circular arrangement
outer layer has longitudinal arrangement
contraction of the 2 layers lead to peristalsis
mouth,pharynx,esophagus and anus all have skeletal muscle
7
Q
What type of connective tissue is found in the serosa
A
loose connective tissue that anchors the organ in place
8
Q
Define peristalsis
A
contraction of the inner and outer layer of the muscularis that result in the propulsion of food and waste through the tract
9
Q
Define the enteric controls of the digestive system.What part of the gi tract is it located?What does it assist in?
A
autonomic control by ~200-600 million neurons
within the submucosal and muscularis layers in small and large intestines
can work independently of CNS control
help with gut motility, blood flow and secretion
10
Q
Define the extrinsic control
A
autonomic input
parasympathetic ( increase activity by vagus nerve) and sympathetic ( decrease)
11
Q
Define buccal cavity
A
oral cavity
surrounded by lips,cheeks,palate, tongue
12
Q
define oral orifice
A
opening of the buccal cavity
13
Q
Define labial frenulum
A
fold that attaches lips to gums inside
14
Q
What type of epithelium is the mouth lined with
A
non-keratinized squamous epithelium
15
Q
Describe the characteristics of the hard palate
A
part of maxillae
creates friction with tongue
16
Q
Define the characteristics of the soft palate
A
skeletal muscle
closes nasopharynx during swallowing
uvula: extends down from it
17
Q
List the 3 functions of the tongue
A
1) reposition food during chewing
2) helps with swallowing, speech and taste
3) anchored to floor of mouth by lingual frenulum
18
Q
What is the tongue papillae and what are the 4 parts
A
surface of tongue
filiform, fungiform, vallate, foliate
19
Q
define filiform
A
creates friction on tongue
20
Q
define fungiform
A
contain taste buds
21
Q
define vallate
A
v-shaped, in back of tonge, contain taste buds
22
Q
define foliate
A
side of tongue
contains taste buds for children and infants
23
Q
What are the 5 functions of salivary
A
1) cleanses mouth
2) dissolves food chemicals for taste
3) moisten food
4) amylase
5) lipase
24
Q
What is the function of amylase in the mouth
A
to break down carbs
25
Whta is the function of lipase in the mouth
to break down fatty acids
26
What is saliva made of?
98% water
electrolytes( sodium, potassium, chloride)
enzymes( amylase, mucin ,lysozyme and IgA antibodies)
metabolic waste ( urea and uric acid)
27
What are the 3 main salivary glands
submandibular glands, sublingual glands, parotid
28
Define submandibular glands
in the floor of the mouth
| secrete saliva through submandibular ducts
29
Define sublingual glands
below the tongue
| secrete saliva through lesser sublingual ducts
30
define parotid glands
in between the skin and masseter muscle, near the ears
| secrete saliva into the mouth through the parotid duct
31
Compare deciduous teeth to permanent teeth
deciduous teeth: baby teeth comes in 6-24 months, roots are reabsorbed when teeth fall out
permanent teeth: by age 21; 32 teeth, third " wisdom" molar comes in age 17-25
32
What are the 4 types of teeth
incisors, canines, premolars, molars
33
define incisors teeth
used for cutting
34
define canines teeth
used for piercing/ tearing meat; fanglike
35
define premolar teeth
grind/crush veggies
36
define molar teeth
best grinders for veggies
37
What is the crown of a tooth and what is it covered by
part above the gums
| covered by enamel
38
What is the root of a tooth
connects tooth to jawbone
39
What id the cement of the tooth
calcified connective tissue
| cover the roots
40
Define periodontal ligament
anchors tooth in bony socket
41
DEFINE DENTIN IN TOOTH STRUCURE
BONELIKE MATERIAL UNDER ENAMEL
42
Define pulp cavity in tooth structure
full of connective tissue,blood vessels and nerves
43
Define root canal in tooth structure
place where pulp cavity joins root
44
Define apical foramen in tooth structure
entry for blood vessels, nerves, etc
45
Define the esophagus and the 2 sphincters that are part of it
flat muscular tubes from laryngopharyx to stomach ( 10 in in length)
two sphincters are upper esophageal spincters and gastroesphageal sphincter
46
Define upper esophageal sphincter
muscles at the top of the sphincter that closes off laryngopharynx to esophagus
47
define gastroesophageal sphincter
closes off esophagus from stomach
48
What are the 3 phases of swallowing/ deglutition
1) voluntary
2) pharyngeal
3) esophageal
49
Define the voluntary phase of deglutition
chewing is complete
tongue will move upward and push back the food
esophageal sphincter is closed
bolus leaves mouth and initiates next step
50
define pharyngeal step of deglutition
upper esophageal spincter relaxes to allow food to enter
uvula and soft palate rise and closes off the nasopharynx
laryngeal muscles contract to prevent food from entering
51
Define the esophageal phase in deglutition
food enters esophagus
peristaltic motion pushes the food toward the stomach
esophageal glands secrete mucus to lubricate the bolus as it moves down
52
Define the cardia in reference to stomach anatomy
entrance to the stomach from the esophagus
53
Define fundus in terms of stomach anatomy
dome-shaped beneath diaphragm
54
Define body in terms of stomach anatomy
midportion
55
Define pyloric part in terms of stomach anatomy
connects stomach to small intestines
56
Define the pyloric sphincter in terms of stomach anatomy
valve that opens and closes between stomach and small intestines
57
Define lesser curvature ( medial/concave) in terms of stomach anatomy
lesser omentum attached between lesser curvature and liver
58
define greater curvature ( lateral/convex) in terms of stomach anatomy
has greater omentum attached
59
Define the greater omentum
made of peritoneal fold
hangs from stomach, down anteriorly over intestines and folds back to attach to transverse colon
has adipose tissue
60
Define the rugae in terms of stomach anatomy
ridges in the stomach creating high surface area and it allows for distension when food enters
61
What does th e mucosa layer of the stomach contain
contains gastric pits ( glands)
| there are 4 types: parietal cells, chief cells, mucous cell, enteroendocrine cell
62
Define the mucous cells of the mucosa layer of the stomach
secretes mucin ( muscus production)
63
Define the parietal cells of the mucosa layer in the stomach tissue
secrete HCL and intrinsic factor ( to absorb vitamin b12)
64
define the parietal cells in the stomach mucosa layer
secrete HCL and intrinsic factor
| to absorb vitamin b12
65
Define chief cells in the stomach tissue of the mucosa layer
secrete pepsin (digest proteins)precursor and lipase ( digest lipids)
66
Define enteroendocrine cell in the stomach tissue of the muscosa layer
secrete gastrin
67
How is the stomach muscosal layer is maintained
mucus rich in bicarbonate which prevent damage to underlying tissues
68
What are the three phases of gastric secretion
cephalic
gasric
intestinal
69
Define chyme
delivered to small intestine
70
Describe the hormonal inputs for stimulating gastric juice secretion
gastric secretion
causes parietal cells to secrete hydrochloric acid
pepsinogen secretion
promotes stomach contractions
71
Describe the neutral input for stimulating gastric juice secretion
acetylcholine (Ach) stimulate gastric juice secretion
72
What are three factors of massive HCL release
Ach+ gastrin+ histamines
73
What percentage of acid secretion occurs in the cephalic phase of food digestion
30% of acid secretion occurs even before food enters the stomach
74
What 3 stimulatory events occur to start the cephalic phase
1) vagus nerve secretes ACh and that activated the parietal cells to release HCL
2) sight and thought of food
3) smell and taste of food
75
What are 2 inhibitory events of the cephalic phase of food digestion
1) loss of appetite ( low pH)
| 2) depression, illness, menopause
76
What percentage of gastric acid secretions are secreted in the Gastric phase
50-60%
77
What 4 things stimulate the release of gastric juices in the gastric phase
1) hormones ( gastrin, ACh, histamine)
2) stomach bloating with food entering the stomach
3) increase pH due to the food
4) food chemicals( caffeine and proteins)
78
When does the intestinal phase of food digestion start
when stomach chyme first enters the small intestine
79
Describe digestion during the intestinal phase
when small intestines bloat and fill with acidic, fatty or salty chyme
then gastric secretion slows down ( inhibit vagus nerve, activate sympathetic)
liver ,pancreas, gallbladder support stimulated ( further lowers secretion of gastric secretion)
80
Describe how the stomach is empty from chyme
chyme dumps in 3 mL amounts into small intestines
usually in 4 hrs
with larger meals it would be faster then 4 hrs
fluids travel fast out of system
81
Describe how the stomach is empty after vomiting
Vomiting occurs due to extreme stretching, irritants, or hormonal activation, Ach activation
vomiting raises the pH of the blood
Alcohol ,bacterial toxins, certain drugs, spicy foods, motion sickness, pregnancy
82
How long and how many sphincters does the small intestines contain
9-15 ft
| 2 sphincters
83
Define the pyloric sphincter
in the small intestines
| ileocecal valve
84
What are the 3 parts of the small intestines and approximate length
Duodenum: 10-15 in
jejunum: 8 ft
lieum: 9-12 ft long
85
Define circular folds
deep folds that slows the movement of chyme
| located in small intestines
86
Deine villi in the small intestines
1 mm extension of mucosa
lacteals embedded within the core of the villi
intestinal crypts in between the villi
87
Define microvilli
miniature filaments on the villi
88
What type of enzymes those the small intestines contain
ones to break down carbs and proteins
89
Define the Brunner Gland's in the duodenum of the small intestines
produce alkaline mucosal secretion that has bicarbonate
| helps neutralize acidic gastric chyme
90
What type of epithelium tisssue is found in the duodenum of the small intestine
Simple columnar epithelium
| that has paneth cells ( maintains the intestinal barrier and defense ( defensins)
91
What is the job of the duodenum
emulsifies fat into micelle to absorb into the blood
92
How are the jejunum and ileum similar to the duodenum
similar to the microanatomy of the duodenum of the duodenum but no paneth cells
93
Define the jejunum of the small intestine
9 ft long
high surface area
where most of biomolecule absorption occurs
94
Define the ilieum of the small intestines
over 9 ft long
| contains peyer's patches
95
What is the mesentary
independent organ
formed from the folds of the peritoneum
attaches the small intestines to posterior abdominal wall
96
What is the function of the mesentary
to store fat, blood vessel and lymph vessels
97
How does Chrohn's disease affect the mesentery
it is thicken and and homeostasis is reduced
98
How many lobes does the liver have
2
| left and right
99
What are 4 reasons the liver is important
1) detoxifying drugs, toxins, etc
2) makes proteins
3) produce bile
4) store glycogen
100
What are the two forms of blood supply to the liver
1) Hepatic Artery ( enters liver frpm abnormal aorta)
| 2) Hepatic Portal Vein( collects blood from GI tract, pancreas, spleen)
101
What is the name of liver cells
hepatocytes
102
Describe how the liver is structured
made of liver lobules
hexagonal shape
each corner has 3 vessels: 1 artery, 1 vein, and a bile ducts
103
What do liver macrophages aid in
help clear debris
104
What are the 5 composition of bile
alkaline solution that has
1) bile salts
2) bile pigments
3) cholesterol
4) triglycerides
5) phospholipids
105
Define bile salts
made of cholesterol to recycle in liver
106
Define bile pigment
bilirubin
| made from the breakdown of RBCs
107
What is the function of the gallbladder
muscular sac that is behind the liver
| stores bile not needed for digestion and concentrates it
108
How do gallstones form
too much cholesterol or not enough bile salt
crystalized cholesterol
prevent flow of bile out of the gallbladder
109
What is the job of the pancreas
to produce and secrete enzymes
| enzymes include: protease, amylase, lipase, and nucleases
110
What 2 hormones are produced in pancreas
glucagon: allows glucose uptake in cells
| insulin: stimulate liver, muscle, adipose to absorb glucose from blood stream
111
What does the pancreas secrete to neutralize chyme when entering small intestines
sodium bicarbonate
112
What is the purpose of the central pancreatic duct
merges with bile duct ( from liver)and feed it into the duodenum
113
Define the acini cells of the pancrea and its purpose
exocrine portion
| produces digestive enzyme
114
What is the first part of the large intestines called
cecum
115
What are the 4 regions of the large intestines
ascending
transverse
descending
sigmoid
116
How many valves those the rectum have and what is the purpose
3
| prevents defecation while passing gas
117
What are the 2 anal sphincters
internal anal sphincter
| external anal sphincter
118
What is the purpose of the internal anal sphincter
involuntary
| smooth muscle
119
What is the purpose of the external anal sphincter
voluntary
| skeletal muscle
120
What is the 3 function of the large intestines
1) water reabsorption
2) process remaining indigestible components of feces
3) where gut microbes ( bacteria, fungi, and protozoans) are colonized
121
What part of the gi has skeletal muscle
mouth,pharynx,esophagus and anus
122
What is the purpose of the gut flora
supplementing the immune system
| processing or producting vitamins and nutrients that diets or small intestines absorption cant help with
