Intro to GI (Exam 1) Flashcards
1
Q
What are the accessory organs of the digestive tract?
A
liver, gallbladder, and pancreas
2
Q
What is the function of rugae?
A
allows stomach to stretch
3
Q
What does oro mean?
A
mouth
4
Q
What type of digestion occurs in the mouth?
A
mechanical digestion with teeth making a bolus and it getting pushed around with saliva and tongue against hard palate
5
Q
What does deglutition mean?
test q
A
swallow
6
Q
The bolus moves from the oropharynx to the pharynx and esophagus and will interact with the epiglottis. What does this result in during deglutition?
test q
A
cessation of breathing
7
Q
What moves the bolus in the esophagus?
A
involuntary peristaltic contractions
8
Q
Is there peristalsis in the stomach?
A
yes
9
Q
In the stomach, once the bolus mixes with digestive enzymes and acids it will become….
A
chyme
10
Q
Where does most absorption occur?
A
SI
11
Q
Is there any absorption in the stomach?
A
small amounts
12
Q
Is there any absorption in the LI?
A
some, mostly water
13
Q
What is the oral cavity formed by?
A
-cheeks
-hard and soft palate
-lips
-tongue
14
Q
What is the vestibule of the oral cavity?
A
area between the cheeks and teeth
15
Q
What is the space called that extends from the gums and teeth to the fauces, the passage between the oral cavity and the oropharynx?
A
oral cavity proper
16
Q
What is the oral cavity lined with?
test q
A
stratified squamous epithelium
17
Q
How many dentitions do you have in a lifetime?
A
2
18
Q
What are deciduous teeth?
A
-primary/milk/baby teeth
-20 teeth that start erupting at 6 months
-1 new pair of teeth per month on average
19
Q
What are the permanent teeth (adult teeth) types?
A
-incisors
-canines (cuspids)
-premolars and molars
20
Q
What is the function of incisor teeth?
A
biting
21
Q
What is the function of canine (cuspid) teeth?
A
tearing
22
Q
What is the function of premolars and molars?
A
crushing and grinding food
23
Q
What does mastication mean?
A
chew
24
Q
What type of digestion is mastication?
A
chewing= mechanical digestion
25
When does the digestion of starches and fats begin?
test q
during mastication with the help of salivary amylase and lingual lipase produced from salivary glands (chemical digestion in the mouth is minor compared to mechanical digestion)
26
What is the function of saliva?
-wets food for easier swallowing, forming bolus, dissolves some food for tasting
-protects mouth from infection via rinsing action
-synthesis is controlled by parasympathetic stimulation
27
What is serous fluid made up of?
-low Na+ and Cl- conc.
-high conc. of K+ and bicarbonate (HCO3-)
-lysozyme is used to help destroy bacteria (the specific one is called thiocyanate)
28
What is salivary amylase?
test q
-also known as ptyalin
-begins starch digestion at pH 6.5-7 found in the mouth
-breaks starches into maltose and dextrin
-when bolus and enzyme hit the pH of 2.5 in gastric juices then hydrolysis ceases (this enzyme doesnt work great in the stomach)
29
What is mucin and what does it promote?
-made up of glycoproteins
-mucin is the main component of mucus
-promotes bacterial aggregation
30
What is lingual lipase secreted by and when does breakdown begin?
test q
-secreted by glands in the tongue
-begins breakdown of triglycerides into fatty acids and glycerol
31
There are 3 pairs of salivary glands. What are they?
test q
1) submandibular gland
2) sublingual gland
3) parotid gland
32
All of the salivary glands have ducts that empty into the...
oral cavity
33
What do the parotid glands secrete?
test q
serous fluid only
34
What do the submandibular and sublingual glands secrete?
test q
mucus and serous fluid
35
The von Ebner's glands have circumvallate/vallate papillae. What do they secrete?
test q
lingual lipase
36
In what instances would salivation increase?
test q
-sight, smell, sounds, memory of food when hungry
-tongue/cheek stimulation (basically anything in mouth)
-cerebral cortex signals the salivary nuclei in brainstem
-parasympathetic ns signals to salivary glands with CN VII and IX
37
What cranial nerves stimulate salivary glands and salivation?
CN VII and IX
38
When does salivation stop?
when afraid (the mouth will become dry)
-this is bc sympathetic tone vasoconstricts arterioles serving glands
39
What is known as a funnel-shaped tube expanding from the internal nares to the esophagus (posteriorly) and the larynx (anteriorly)?
pharynx
40
The pharynx is skeletal muscle lined by ________ membrane
mucus
41
T/F: the pharynx is a common passageway for food and air
true
42
The oropharynx is from the ___________ to palatoepiglottic fold
soft palate
43
Fauces are an opening from the mouth into the....
oropharynx
44
The laryngopharynx/hypopharynx extends from the palatoepiglottic fold to the inferior end of ______________. The laryngopharynx ends at the ___________ posterioinferiorly
cricoid cartilage, esophagus
45
What tissue lines the pharynx?
stratified squamous epithelium
46
The esophagus has 3 portions of muscles. What are they?
upper 3rd portion= skeletal muscle
middle 3rd= skeletal and smooth muscle
inferior 3rd/ terminal portion near stomach= smooth muscle
47
T/F: the esophagus is a muscular tube
true
48
Where does mechanical digestion occur?
1) mouth during chewing
2) stomach churning
3) SI segmentation
49
Where does propulsion occur?
1) oropharynx during swallowing
2) esophagus, stomach, SI, and LI during peristalsis
50
Which part of the digestive tract is collapsed at rest, flat in upper 2/3 and rounded in lower 1/3?
esophagus
51
Where does the esophagus begin?
at the lower border of the cricoid cartilage (approx. C6)
52
Which part of the digestive tract descends along the front of the spine, through the posterior mediastinum, passes through the diaphragm at the cardiac hiatus?
esophagus
53
Which part of the digestive tract enters the abdomen and terminates at the cardiac office of the stomach?
esophagus
54
The esophagus secretes ________ and transports ingested food to the stomach
mucus
55
The mucosal layer of the esophagus contains what type of epithelium?
test q
stratified squamous epithelium
56
The submucosal layer of the esophagus and stomach is made up of what tissue?
test q
areolar connective tissue
57
The muscularis externa of the esophagus has 2 layers. What are they?
test q
longitudinal (outer) and circular (inner) layer
58
The adventitia layer of the esophagus is made up of what tissue?
test q
fibrous connective tissue
59
The submucosa of the esophagus has large ________ glands
test q
mucous
60
The muscularis of the esophagus has 3 types of muscle. What are they and where?
test q
top 1/3 is skeletal muscle
middle 1/3 is skeletal+ smooth muscle
bottom 1/3 is smooth muscle
61
The upper and lower esophageal sphincters are prominent _________ muscle (of the muscularis layer)
circular
62
What are the other names for mechanoreceptors?
pressure receptors/sensors and baroreceptors
63
What stage of deglutition is this?
-begins when the bolus gets pushed against the hard palate with the tongue and is forced into the oropharynx
-pressure receptors in the oropharynx stimulate the deglutition center in the medulla
voluntary stage
64
What stage of deglutition is this?
-moves food from the pharynx to the esophagus
-breathing stops and airways are closed
-soft palate and uvula are lifted to close off nasopharynx
-epiglottis is bent over airway as larynx is lifted
test q
pharyngeal stage
65
What stage of deglutition is this?
-begins when the bolus enters the esophagus
-peristalsis moves the bolus from the esophagus to the stomach
esophageal stage
66
During swallowing, the upper esophageal sphincter relaxes when the __________ is lifted
larynx
67
During swallowing, the primary peristalsis wave pushes the food down. The ___________ fibers are behind the bolus, and the ___________________ fibers are in front of the bolus to shorten the distance of travel
test q
circular, longitudinal
68
What travels down the esophagus faster- solids or liquids?
liquids
69
When does the lower esophageal sphincter relax?
when the food approaches
70
define dysphagia
difficulty swallowing
71
Steps of deglutition:
1) The upper esophageal sphincter is contracted. During the buccal phase, the tongue presses against the _____________, forcing the food bolus into the oropharynx where the involuntary phase begins
2) The uvula and __________ rise to prevent food from entering respiratory passageways. The tongue blocks off the mouth. The upper esophageal sphincter relaxes, allowing food to enter the esophagus
3) The constrictor muscles of the pharynx contract, forcing food into the esophagus inferiorly. The upper esophageal sphincter contracts (closes) after entry
4) Food is moved through the esophagus to the stomach by peristalsis
5) The gastroesophageal sphincter opens and food enters the stomach
hard palate, larynx
72
Peristalsis is ____________ mixing
propulsive
73
What is the stimulus for peristalsis of the esophagus?
test q
distension
74
What type of irritation in the esophagus can turn on peristalsis?
test q
chemical or physical irritation
75
Name these stages:
A) _______________- chyme is pushed toward the closed pylorus
B) _____________- the antrum churns the trapped material
C) ______________- chyme is pushed back into the proximal stomach
Test q
A) propulsion
B) grinding
C) retropulsion
76
If the lower esophageal sphincter fails to open, then the.....
distention of the esophagus will start to feel like chest pain/heart attack
77
If the lower esophageal sphincter fails to close, the stomach acids will enter the esophagus and cause heart burn. Laying down after eating or eating a big meal will weaken the sphincter. Smoking, alcohol, and mint oil can cause the sphincter to relax, worsening the situation. What disease is this?
gastroesophageal reflux disease (GERD)
78
What is lamina propria?
cell glue, next to all epithelial tissue
79
What are the 3 parts of the small intestine?
duodenum, jejunum, ilium
80
What does the submucosal gland of the submucosa secrete?
mucus
81
What is another name for the meissner nerve plexus?
submucosal nerve plexus
82
What is another name for the auerbach nerve plexus?
myenteric nerve plexus
