GI II Flashcards
What is the 4 basic layers to the wall of GI tube?
1) mucosa
2) submucosa
3) muscularis externa
4) serous/adventitia
What three components constitutes mucosa?
1) epithelium resting on basal lamina
2) lamina propria
3) muscularis mucosae
Most of the GI tract will have this type of epithelium
simple columnar
Which 3 portions of the GI tract will have a different type of epithelium? What type of epithelium is it?
1) proximal GI tube (esophagus)
2) distal end of GI tube
3) distal anal canal
stratified squamou
What’s in lamina propria (4)?
1) connective tissue
2) glands
3) blood vessels
4) lymphatic tissue
What are the two layers of smooth muscles in muscualris mucosae?
1) inner circular
2) outer longitudinal
What is the purpose of the two layer of smooth muscles in muscularis mucosae?
when contracting, they wrinkle the mucosa, increasing surface area, which facilitates absorption of nutrients and secretion
True or false. Glands can be found in the submucosa.
True. glands can be found in this layer in the esophagus and duodenum (all others are in lamina propria)
What type of connective tissue is present in the submucosal layer?
dense irregular
Besides connective tissue, what else can be found in the submucosa?
1) glands (in esophagus and duodenum)
2) blood and lymphatic vessels
3) submucosal or Meissner’s plexus
How many layers of smooth muscles are in muscularis externa?
two: inner circular and outer longitudinal
What’s the function of muscularis externa?
contraction result in peristasis
Myenteric (Auerbach’s) plexus is located in which layer?
muscularis externa
What’s the difference between adventitia and serosa?
serosa has an extra layer (mesothelium) located external to muscularis externa. adventitia has connective tissue layer only
What kind of nerve fibers are found in submucosal (Meissner’s) plexus?
1) parasympathetic postganglionic neurons
2) sympathetic postganglionic fibers
What’s the function of Meissner’s plexus (3)?
regulate glandular activity, blood flow, muscualris mucosae and is sensory
What kind of nerve fibers are found in myenteric (Auerbach’s) plexus?
1) parasympathetic postganglionic neurons
2) sympathetic postganglionic fibers
What’s the function of Auerbach’s plexus?
regulate peristalsis
What does achalasia affect?
esophagus
What is Hirschsprung’s disease?
congenital megacolon
What type of epithelium is present in esophagus?
stratified squamous, nonkeratinized
What distinctive feature is found in the lamina propria of the esophagus?
cardiac esophageal glands
Mucularis mucosae of the esophagus is better developed in which section?
distal portion of esophagus
What type of glands are found in submucosa of esophagus?
esophageal glands proper (seromucous)
The upper 5% of the esophagus is comprised of which type of muscle?
skeletal
Upper esophagus is comprised of which type of muscle?
skeletal and smooth
The lower 50% or greater of esophagus is comprised of which type of muscle?
smooth
Which part of the esophagus has adventitia?
thoracic esophagus
Which part of the esophagus has serosa?
abdominal esophagus
To confirm the diagnosis of Barrett’s esophagus, what must be seen in a micrograph?
metaplastic columnar epithelium with goblet cells