GI system Week 5 test 2 Flashcards
Receiving and processing unit
mouth through the stomach
extraction and disposal unit
small intestine through the anus
The 4 general layers of the Gut tube
Mucosa
Submucosa-dense irregular CT
Muscularis-smooth muscle
Serosa/Adventitia- CT holding everything together
What are the layers of the mucosa
Epithelium
lamina propria
muscularis mucosa
Difference between serosa and avdentitia
serosa: CT which is also covered with mesothelium
adventitia: CT w/out mesothelium and generally connects one organ to another
T/F retroperitoneal organs will have both adventitia where attached to another organ and serosa everywhere else
True
what is peristalsis
the alternating contraction of smooth muslce
Smooth muscle layers of the digestive tract
inner is circular
external is longitudinal
this is not the case in pharynx, top of esophagus, and external anal sphincter, these are skeletal muscle
what is segmentation
nonadjacent segments of alimentary tract organs alternately contract and relax, moving the food forward then backward. Food mixing and slow food propulsion occurs.
The 3 layers of the pharynx
- Mucosa-non keratinized strat. squam. loose CT containing longitudinal fibers
- *no muscularis mucosa/submucosa**
- Muscularis externa: both circular and longitudinal skeletal muscle
- Adventitia
When swallowing what do the trachealis muscles do so that the upper esophageal sphincter can open
the relax and make it so the trachea can compress slightly to allow food down the esophagus
The esophagus muscle comonents
upper 1/3 is skeletal
middle 1/3 is mixed smooth and skeletal
lower 1/3 is only smooth
Distinction between the vagina and the esophagus histologically
the esophagus has esophageal glands in the submucosa and lamina propria which aid the passage of food, the vagina on the other hand does not have these glands
The lower esophageal sphincters is formed by what?
from the smooth muscle layer of the muscularis externa
What is GERD
Gastro-Esophageal Reflux Disease, this happens when the lower esophageal sphincter doesn’t close properly
At the junction of the esophagus and stomach what is the epithelium change that occurs
Stratified squamous to simple columnar
At the stomach bolus is changed to chyme as acid mixes in, what are some other enzymes that are produced in the stomach that aid in food break down
Lipase and pepsin and remember absorbing food doesn’t really happen here
Pit and gland size of these areas
Cardia
Body/Fundus
Pyloris
- Cardia: pits shorter than glands
- Body/Fundus: relatively long glands, but pits are more defined than in cardia
- Pylorus: longer pits than glands
Glands of the cardia
almost exclusively mucous glands, which help things glide into the stomach