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Flashcards in Gastrointestinal I Deck (185)
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1
Q

How long is the GI tract in a cadaver?

A

30 feet

2
Q

How long is the living GI tract?

A

around 15 feet

3
Q

Divisions of the small intestine:

A

Duodenum
Jejunum
Ileum

4
Q

Divisions of the Large Intestine:

A
Cecum
Ascending
Transverse
Descending
Sigmoid
5
Q

4 functions of the GI tract:

A

Motility
Secretion
Digestion
Absorption

6
Q

What are the constant low levels of contractions in the GI tract know as?

A

Tone

7
Q

What is the purpose of tone?

A

Maintain steady pressure

8
Q

What are the 3 types of motility?

A

Propulsive (peristalsis)
Segmentation (mixing)
Tonic contractions (sphincters/valves)

9
Q

2 functions of Segmentation?

A

Mechanical digestion

Facilitate absorption

10
Q

6 sphincters in the GI tract:

A
UES - Upper Espophageal Sphincter
LES - Lower Esophageal Sphincter
Pyloric
Ileocecal
Internal Anal
External Anal
11
Q

What regulates the movement of contents of the common bile duct into the duodenum?

A

Sphincter of Oddi

12
Q

Where are the voluntary areas of control in the GI tract?

A

UES
External Anal Sphincter

*the ends

13
Q

What do the voluntary control areas in the GI tract have in common?

A

Skeletal muscle

instead of smooth

14
Q

How much saliva and gastric juice are produced daily?

A
  1. 5 L saliva

2. 5 L gastric juice

15
Q

How much bile and pancreatic juice are produced daily?

A
  1. 5 L bile

1. 5 L pancreatic

16
Q

How much intestinal secretion and mucus are produced daily?

A
  1. 0 L intestinal

2. 0 L mucus

17
Q

Most chemical digestion takes place via…

A

Hydrolysis

18
Q

Where are the brush border enzymes?

A

Plasma membrane of enterocytes

19
Q

How much fluid enters into or is secreted into the lumen of the intestine every day?
How much ends up in the stool?

A

9.0 L

100 mL

20
Q

Where to the 4 basic quadrants intersect?

A

Belly button

21
Q

What are the 9 Abdominal-Pelvic regions?

A
Rt and Lt Hypochondirac
Epigastric
Rt and Lt Lumbar
Umbilical 
Rt and Lt Inguinal 
Pubic
22
Q

What layer covers the external surfaces of most digestive organs?
What is it continuous with?

A

Visceral peritoneum

Parietal peritoneum

23
Q

What lies between the visceral and parietal peritoneum?

A

Peritoneal Cavity

*with peritoneal fluid
lubricates

24
Q

What is inflammation of the peritoneum?

A

Peritonitis

25
Q

What is the condition of accumulated peritoneal fluid called?

A

Ascites

26
Q

What is a large fold of peritoneum in the abdominal cavity?

A

Greater Omentum

27
Q

What is the greater omentum attached to?

A

Transverse colon

28
Q

What anchors the small intestine to the posterior abdominal wall?

A

Mesentery

29
Q

T/F

The contents within the lumen are technically outside the body

A

True

30
Q

What condition penetrates the gastric mucosal barrier?

A

Peptic Ulcer Disease (PUD)

31
Q

What is obstructed in Acute Pancreatitis?

A

Main pancreatic duct
(causing rupture)

*damages pancreas, duodenum

32
Q

What can cause peritonitis via bacterial invasion?

A

Ruptured appendix

33
Q

What are the 4 major layers of the GI tract wall?

A

Mucosa
Submucosa
Muscularis Externa
Serosa

34
Q

What delineates the Mucosa and Submucosa?

A

Muscularis mucosae

35
Q

What is the self-induced electrical activity in the digestive smooth muscle called?
(3 things)

A

Slow-wave potential
Basal Electrical rhythm (BER)
Pacemaker potential

36
Q

What are 2 terms for the submucosal and myenteric plexuses in the gut?

A

Intrinsic Nerve Plexuses
Enteric Nervous System

*sensory, motor, exocrine, endocrine, etc.

37
Q

What is the parasympathetic innervation for the esophagus, stomach, small intestine, and ascending colon?
(upper GI tract)

A

Vagus

38
Q

The mixed vagus nerves innervating GI tract are what percentage afferent and efferent?

A

Afferent: 75%
Efferent: 25%

39
Q

What 4 GI tract structures does the Vagus nerve innervate parasympathetically?

A

Esophagus
Stomach
Small Intestine
Ascending colon

40
Q

What is the parasympathetic innervation for the lower GI tract?
(transverse, descending, sigmoid colons and anal canal)

From where are they derived?

A

Pelvic splanchnic nerves

S2, S3, S4

41
Q

The majority of parasympathetic nerves to the GI are ____.

Some are _____.

A

Cholinergic

Peptidergic

42
Q

Name 4 peptidergic molecules.

A

VIP
Enkephalins
Neuropeptide Y
Substance P

43
Q

What are the 3 divisions of Adrenergic (sympathetic) ganglia that serve the GI tract?

A

Celiac
Superior mesenteric
Inferior mesenteric

44
Q

What percentage of Adrenergic nerves to the GI tract are afferent and efferent?

A

50/50

45
Q

T/F
Autonomic nerves influence GI tract altering nerve activity, altering hormone secretion, and innervating smooth muscle and glands

A

True

46
Q

What secretes hormones in the GI tract?

A

Endocrine cells

47
Q

What condition is marked by no salivary production and increased caries?

A

Xerostomia

48
Q

What autoimmune disease strikes salivary glands?

A

Sjogren’s Syndrome

  • most common cause of xerostomia
  • *mostly women
49
Q

Name 4 diseases that can cause xerostomia.

A

Sjogren’s
HIV
Diabetes
Parkinsons

50
Q

What receptors mediate normal salivary function?

A

M3

muscarinic

51
Q

What 3 components make up a salivary gland?

A

Acinus
Intercalated duct
Striated duct

52
Q

What surrounds each acinus in the salivary gland?

Function?

A

Myoepithelial cells

Contraction and release of saliva

53
Q

What are the 3 categories of salivary acinii?

A

Serous
Mucous
Mixed

54
Q

What percentage of total saliva doe each gland produce?

A

Submandibular - 71%
Parotid - 25%
Sublingual - 3-4%

55
Q

What type of secretions do each of the salivary glands produce?

A

Parotid - serous
Submandibular - mixed
Sublingual - mucous

56
Q

What do the salivary glands look like under a microscope?

A

Parotid - mostly dark (lack of mucous)
Submandibular - mixed dark and light
Sublingual - mostly white

57
Q

What ducts drain the salivary glands?

A

Parotid - Stenson’s
Submandibular - Wharton’s
Sublingual - Ducts of Rivinus

58
Q

What are the 3 most important salivary proteins?

A

Alpha-amylase
Lingual Lipase
Mucins

59
Q

What does salivary alpha-amylase cleave?

What deactivates?

A

Internal Alpha1,4

(no terminals or Alpha 1,6)

Gastric Acid

60
Q

What are 3 antibacterial components of Saliva?

A

Lysozyme (targets walls)
Lactoferrin (chelates iron)
IgA

61
Q

How many species of bacteria are in the oral cavity?

A

700

62
Q

Name 4 oral bacteria and 1 anaerobe.

A

Streptococci
Lactobacilli
Staphylococci
Corynebacteria

Bacteroides

63
Q

Three benefits of normal oral cavity flora.

A

Prevent colonization
Inhibition of non-indigenous species
Stimulates cross reactive antibodies
(antibody immune response)

64
Q

T/F

Saliva contains buffering agents and minerals

A

true

65
Q

At what pH can enamel be dissolved?

A

below 5.5

66
Q

Where is the salivary center?

A

Medulla

67
Q

Describe what the sympathetic response does for Salivary Output.

A

Scant
Protein rich
High K+ and HCO3-

68
Q

T/F

Sympathetic and parasympathetic stimulation increase salivary secretion.

A

True

*but very different in character

69
Q

What agents reduce salivary secretion?

A

Atropines

Cholinergic blockers

70
Q

How many different chemicals can taste buds detect?

A

4-10k

71
Q

Name 3 types of papillae.

A

Fungiform
Foliate
Circumvallate

72
Q

What papilla is scattered over the entire tongue and responds to sweet and salty (and sour)?

A

Fungiform

73
Q

What papilla responds mainly to sour?

A

Foliate

74
Q

What are fungiform papillae taste buds innervated by?

Circumvallate?

A

CN VII - chorda tympani branch

CN IX - glossopharyngeal

75
Q

What papillae responds best to bitter substances?

A

Circumvallate

76
Q

Taste buds in the epiglottis are innervated by…

A

X - vagus

77
Q

Taste buds in the palate are innervated by…

A

VII - facial nerve

78
Q

T/F

Taste receptor cells are neurons

A

False

but synapse onto VII, IX, and X

79
Q

What is at the taste pore?

A

Microvilli

80
Q

What taste depolarizes membrane through influx of Calcium and sodium and inhibiting K+ efflux via cAMP?

A

Bitter

81
Q

What taste goes through cascade ultimately releasing calcium into the cell?

A

Alkaloid

??

82
Q

What taste relies on influx on Na+?

A

Salty

83
Q

What taste relies on H+ to block channel and impede K+ from exiting the cell?

A

Sour

84
Q

What taste acts through cAMP and PKA to inhibit K+ from exiting cell thus depolarizing the membrane?

A

Sweet

85
Q

Where do gustatory cranial nerves terminate?

A

Solitary nucleus in the medulla

Rostral 1/2

86
Q

Where does output of the Nucleus of the Solitary Tract lead?

2 places

A

Ventroposterior medial nucleus of the Thalamus
(VPM)

Insular Cortex

*this is why bad taste in mouth after seizure

87
Q

T/F

Lower 3rd molar extraction causes gustatory loss by impacting the Lingual Nerve

A

False

only temporary, and not detectable by pt

88
Q

The lingual nerve is a branch of…

A

Trigeminal (mandibular division)

*sensory innervation to the tongue

89
Q

4 muscles of mastication.

A

Temporalis
Lateral Pterygoid
Medial Pterygoid
Masseter

90
Q

What innervates the muscles of mastication?

A

V Mandibular Division

91
Q

Action and innervation Masseter:

A

Elevate mandible

Masseteric branch Mandibular V

92
Q

Temporalis Action and innervation:

A

Elevates mandible

Deep temporal branch Mandibular V

93
Q

Lateral Pterygoid action and innervation:

A

Protrudes mandible

Lateral pterygoid branch Mandibular V

94
Q

Medial Pterygoid action and innervation:

A

Elevates mandible

Medial pterygoid branch Mandibular V

95
Q

Depression, elevation, lateral, and anterior-posterior movement creates what in the jaw?

A

Looping pattern

96
Q

Three phases of mastication:

A

Opening
Closing
Occlusal (longest component)

97
Q

What depresses the mandible?

3 muscles, 1 force

A

Gravity
Digastric
Geniohyoid
Mylohyoid

98
Q

How long is the esophagus?

Thick?

A

18-26 cm
2 cm (ant/post)
3cm (lateral)

99
Q

What vertebral level does the esophagus begin?
traverse diaphragm?
cardi of orifice?

A

C5-6
T10
T11

100
Q

What type of epithelium is the esophagus lined with?

A

non-keratinized stratified squamous

101
Q

What provides mucus for the esophagus?

A

Esophageal Glands

102
Q

3 layers of esophageal wall?

A

Mucosa
Submucosa
Muscularis

103
Q

What anatomical difference is there in the esophagus compared to the rest of the GI tract?

A

No Serosal outer layer

thin connective tissue instead

104
Q

T/F

The esophagus has small veins

A

False

especially large gastric veins

105
Q

What can cause bumps in the esophagus?

What is this called?

A

Submucosal venous spaces fail to drain

Esophageal Varices

106
Q

What causes esophageal varices?

A

portal hypertension

*cirrhosis

107
Q

3 phases of Deglutition (swallowing):

A

Oral/voluntary
Pharyngeal
Esophageal

108
Q

What relaxes in the Involuntary pharyngeal phase?

A

Upper Esophageal Sphincter

109
Q

What accounts for the inhibition of respiration and stimulation of glottic closure during deglutition?

A

Reflex Response

110
Q

Peristalsis in the esophagus terminates at:

A

Lower Esophageal Sphincter

111
Q

What condition entails the Lower Esophageal Sphincter’s inability to relax?

A

Achalasia

  • doesn’t open
  • entire meals back up this way
112
Q

What common condition leads to heartburn and esophagitis (and ulceration and scarring)?

A

GERD - gastroesophageal reflux disease

113
Q

What causes GERD?

What really bad thing is associated with it?

A

decrease in LES pressure
(doesn’t close)

esophageal adenocarcinoma

114
Q

T/F

Steroidal based oral contraceptives decrease closing strength of the LES

A

True

along with caffeine, peppermint, spicy, citrus, smoking

115
Q

What is a complication from persistent GERD?

A

Barrett’s esophagus and strictures

116
Q

What causes strictures from persisted GERD?

A

Scar tissue, spasm, and edema

117
Q

What do strictures in the esophagus cause?

A

Difficulty swallowing (dysphagia)

118
Q

What is the term for painful swallowing?

A

Odynophagia

119
Q

What indicated Barrett’s esophagus when looking down esophagus?

A

Red lining

with “tongues” indicating erosion

120
Q

What replaces squamous mucosa in Barrett’s esophagus?

A
Columnar epithelium 
(resembling stomach/intestine)
121
Q

What are the 4 main regions of the stomach?

A

Cardia
Fundus
Body
Pylorus

122
Q

What are the 2 sphincters in the stomach?

A

LES - Lower Esophageal Sphincter

Pyloric

123
Q

What defines the border of the Fundus to the Body?

A

Cardial notch

124
Q

Where does the Greater Omentum hang from?

A

Greater curvature of the stomach

125
Q

What are the 3 layers of muscularis musosa in the stomach?

A

Longitudinal (outer)
Circular (middle)
Oblique (inner)

126
Q

What acts as the protective barrier in the gastric lining?

A

Alkaline mucus

with a lot of Bicarb

127
Q

What enhances mucous production in the stomach?

A

Prostaglandins

128
Q

What is the turnover rate of the lining of the stomach?

A

2-3 days

129
Q

What type of epithelium is in the stomach?

A

Simple columnar

130
Q

What are the deep channels in the simple columnar epithelium of the stomach?

A

Gastric pits

131
Q

What are the 4 main gastric glands?

A

Mucous neck cells
Parietal Cells
Chief cells
Endocrine cells

132
Q

What type of cells secrete the alkaline mucous?

A

Mucous neck cells

133
Q

What to Parietal cells secrete?

A

HCL and IF

134
Q

What do Chief cells secrete?

A

Pepsinogen

Gastric Lipase

135
Q

What cells secrete gastrin and histamine?

Specifically?

A

Endocrine cells

G cells - gastrin
ECL (enterochromaffinlike) - Histamine

136
Q

How much gastric juice is secreted daily?

A

2500 mL

137
Q

Where are most Parietal cells located in the stomach?
Where are most Chief cells located?
G cells?

A

High body toward fundus
Body
Antrum

138
Q

What does Gastrin stimulate?

A

Parietal cells (IF and HCL)

139
Q

What 2 hormones are secreted by the stomach?

A

Gastrin

Histamine

140
Q

What is chyme?

A

Mixed food

combined with gastric juice

141
Q

What causes the Alkaline Tide?

A

HCl production in Parietal cells from Bicarb

HCO3- released into blood and causes temporary alkalinity

142
Q

T/F

The vagus nerve stimulates gastric secretion while food is still in the mouth (cephalic phase).

A

True

143
Q

Describe the positive feedback loop in the stomach.

*What phase does this take place?

A

Gastrin (via vagal or distention stimuli)
stimulates gastrin secretion

(which stimulates more Gastrin, etc)

*Gastric Phase

144
Q

What increases HCL secretion from parietal cells?

A

Histamine

145
Q

How does Pepsin break apart AA’s?

A

Partially

can only cut certain linkages

146
Q

What 3 hormones in the duodenum act to decrease gastric juice secretion?

A

CCK
Secretin
GIP (gastric inhibitory peptide)

147
Q

What hormone released by the duodenum inhibits gastric motility?

A

GIP

148
Q

What 3 signals stimulate H+ secretion in the stomach?

A

Histamine
Gastrin
Vagal (via Ach)

149
Q

What inhibits the vagus nerve activity that stimulates the stomach?

A

Enterogastric Reflex

150
Q

CCK, secretin, and GIP all _____ gastric motility and emptying

A

inhibit

151
Q

What can cause acute gastritis?

A

Bacterial endotoxins, alcohol, aspirin, etc

152
Q

What can cause chronic gastritis?

A

Helicobacter pylori

153
Q

What does H. pylori produce that allows it to live in the stomach?

A

Urease

NH3 neutralizes stomach acid

154
Q

What condition entails the prolapse of the stomach through the diaphragmatic/esophageal hiatus?

A

Hiatal Hernia

155
Q

T/F

Hiatal hernias are more common in men

A

False

pregnancy pushing

156
Q

T/F

Abdominal ascites is associated with hiatal hernia

A

True

157
Q

Where is B12 absorbed?

A

Terminal ileum

158
Q

T/F

Pernicous anemia is characterized by megaloblasts that lack biconcavity and live for days

A

False

Live for weeks rather than months

159
Q

What are 2 oral manifestations of Pernicious Anemia?

A
Erythma/atrophy of tongue
Megaloblastic anemia (red lesions in mucosa)
160
Q

4 consequences of Emesis.

A

Acid-base disorders
volume/electrolyte depletion
Malnutrition
Aspiration Pneumonia

161
Q

What phase of emesis is the antrum contracting and the cardia relaxing?

A

Retching

162
Q

How does the diaphragm contract during emesis?

A

Downward

*facilitates opening of esophagus and LES

163
Q

What two muscles are simultaneously contracted in emesis?

A

Diaphragm downward

Abdominals

164
Q

What controls vomiting in brain?

A

Bilateral Vomiting Centers

165
Q

What is located on the floor of the 4th ventricle in the brain?

A

Chemoreceptor Trigger Zone

*can initiate vomiting

166
Q

What salivary flow rate is used to diagnose Sjogrens?

A

Less than 0.1 mL/min

167
Q

What 2 classes of drugs cause Xerostomia?

A

Anti-Muscarinics

Beta-2 Agonists

168
Q

Example of a LABA (Long Acting Beta-2 Agonist) used to prevent asthma.

A

Salmeterol

169
Q

Muscarinic Antagonist used as a bronchodilator.

A

Ipratropium

170
Q

Muscarinic Antagonist used for Incontinence (also increases heart rate)

A

Oxybutynin

171
Q

What anti-histamine decreases salivary production?

A

Benadryl

172
Q

Diuretic that decreases salivary secretion due to overall body fluid loss.

A

Hydrochlorothiazide

173
Q

Nasal decongestant and vasoconstrictor that decreases salivary action.

A

Phenylephrine

174
Q

Muscarinic Antagonist

A

Benztropine

175
Q

How does Pilocarpine (Salagen) increase salivation?

A

Stimulates Muscarinics

176
Q

How does Cevimeline (Evoxac) stimulate salivation?

A

Muscarinic Agonist (Ach mimicker)

177
Q

What lubricant rinse helps with Xerostomia?

A

Biotene Oral Balance

178
Q

T/F

Steroids (like Fluticasone) causes dry mouth

A

True

179
Q

What is a very common side effect of corticosteroids?

A

Thrush (Candida albicans)

180
Q

What is the best treatment for Oral Thrush?

A

Fluconazol

181
Q

Why do non-specific Cox inhibitors cause stomach pain?

A

Decreases Prostaglandin activity and depletes stomach lining

182
Q

What is the physiological prostaglandin?

Inflammatory?

A

Cox 1

Cox 2

183
Q

What two antibiotics are prescribed for Peptic Ulcer Disease?

A

Clarithromycin

Amoxicilin

184
Q

What drug acts as a PPI (Proton Pump Inhibitor)?

A

Esomeprazole

185
Q

What drug acts as a Histamine-2 Receptor Blocker?

and partially inhibits H+ gastric secretion

A

Ranitidine

Decks in Tim's Cards Class (140):