Digestive System

Question 1

<p>What are the parts of the digestive system? (4 plus accessory)</p>

Answer 1

<p>Esophagous, stomach, small intestine, large intestine, + intrinsic glands</p>

Question 2

<p>What are the layers of the digestive system where it is not continuous with mesentery?</p>

Answer 2

<p>Mucosa, submucosa, muscularis externa &amp; serosa</p>

Question 3

<p>What are the layers of the digestive system where it is continuous with mesentery</p>

Answer 3

<p>Mucosa, submucosa, muscularis externa, and adventitia</p>

Question 4

<p>What is the epithelium of the esophagus?</p>

Answer 4

<p>Stratified, squamous, nonkeratinized epithelium</p>

Question 5

<p>What is the purpose of esophageal cardiac glands and esophageal glands proper?</p>

Answer 5

<p>Secrete mucous and some secrete serous cells and lysozyme</p>

Question 6

<p>Where are the mucus secreting glands located in the esophagus?</p>

Answer 6

<p>The lamina propria (esophageal cardiac glands) and the submucosa layer (esophageal glands proper)</p>

Question 7

<p>Describe the musculature of the esophagus?</p>

Answer 7

<p>Upper third, striated in externa, middle third, smooth and striated, lower third, smooth</p>

Question 8

<p>What is the purpose of the esophagus?</p>

Answer 8

<p>To convey bolus from pharynx to stomach</p>

Question 9

<p>What ensures the bolus in transported one directionally?</p>

Answer 9

<p>2 physiologic sphincters, pharyngoesophageal and gastroesophageal</p>

Question 10

<p>What sphincter initiates swallowing?</p>

Answer 10

<p>Upper esophageal sphincter</p>

Question 11

<p>What keeps acid reflux from stomach into esophagus?</p>

Answer 11

<p>Lower esophageal sphincter</p>

Question 12

<p>What does persistant acid reflux lead to?</p>

Answer 12

<p>GERD - gastroesophageal reflux disease</p>

Question 13

<p>What are the symptoms of GERD over time?</p>

Answer 13

<p>Ulceration, difficulty swallowing (dysphagia), fibrosis and stricture of Lower esophagus</p>

Question 14

<p>DDX: Abnormal growth of simple columnar cells in lower esophagous. Increased incidence of adenocarcinoma of esophagous. Increased susceptibility to injury to stomach acid injury</p>

Answer 14

<p>Barrett's esophagus</p>

Question 15

<p>DDX: Incomplete closure of esophageal diaphram. Reflux esophagitis and ulceration. Difficulty swallowing and &quot;lump in the throat&quot; feeling</p>

Answer 15

<p>Hiatal Hernia</p>

Question 16

<p>What does the stomach do to the bolus?</p>

Answer 16

<p>Acidifies it and converts it into chyme</p>

Question 17

<p>Describe the musculature of the stomach</p>

Answer 17

<p>Rugae - longitudinal folds of the mucosa and submucosa which disappear when stomach is distended</p>

Question 18

<p>Describe what depth of gastric pit tells you about stomach location?</p>

Answer 18

<p>Pits are shallowest in cardia and deepest in pylorus</p>

Question 19

<p>What is the defining feature of the cardia of the stomach?</p>

Answer 19

<p>It is mucus secreting via tubular glands with coiled ends</p>

Question 20

<p>What is the primary contributor to gastric juice? What kind of cells secrete it?
</p>

Answer 20

<p>The fundus is the primary contributor.

Parietal and chief cells
</p>

Question 21

<p>Describe the gastric pits in the pylorus</p>

Answer 21

<p>Deep gastric pits with branched glands. Primary mucus secreting and some parietal cells and gastrin secreting G ccells</p>

Question 22

<p>What is the epithelium of the stomach?</p>

Answer 22

<p>Simple columnar, mucus producing but not goblet</p>

Question 23

<p>What is located in the lamina propria of the stomach?</p>

Answer 23

<p>Loose CT with smooth muscle, lymphocytes, plasma, mast cells, and fibroblasts</p>

Question 24

<p>What is included in the gastric mucosa?</p>

Answer 24

<p>Epithelium, lamina propria, gastric glands, and muscularis mucosa</p>

Question 25

<p>What is the muscularis mucosae?</p>

Answer 25

<p>A poorly defined inner circular layer and an outler longitudinal layer of smooth muscle. Sometimes has an outermost circular layer</p>

Question 26

What is present in the gastric submucosa?

Answer 26

Desnce irregular collagenous CT with fibroblasts, mast cells, and lymphoid elements in the connective tissue

Messner’s plexus

Question 27

What is present in the muscularis externa?

Answer 27

3 smooth muscle layers: incomplete inner oblique, thick middle circular, outer longitudinal layer

Aurbachs plexus located between middle and outer layer

Gastric serosa around whole thing

Question 28

What layer of muscle makes the pyloric sphincter?

Answer 28

Thick middle circular

Question 29

What influences the rate at which the stomach empyies?

Answer 29

Viscosity, pH, lipid content, osmolality, caloric density

Question 30

What gastric glands are present in the fundus and body?

Answer 30

Simple tubular

Question 31

Describe the parts of a gastric pit and what is located in each

Answer 31

Pit - entrance into gastric glands - contains simple columnar mucinogenic cells renewed every 3-5 days

Isthmus - connection of “fingers” of gland to the gastric pit - contains regenerative cells, neck cells, parietal cells

Neck - Entrance into each finger of the gland - Contains mucous neck cells and parietal cells

Base - bottom of fingers - contains all cells above (excluding surface cells) plus neuroendocrine cells

Question 32

What do surface lining cells secrete?

Answer 32

Mucous granules with cloudy, thick, viscous mucous with high bicarbonate content fror acid protection

Question 33

How often are surface lining cells renewed?

Answer 33

Every 3-5 days

Question 34

What are the features of mucous gland cells? what do they secrete?

Answer 34

Short microvilli, apical mucous granules, prominent golgi, shorter columnar cell than surface lining

Secrete soluble mucous not as thick as surface lining

Controlled by vagal stimulation