7- Histology of Esophagus & Stomach Flashcards
What are the four layers of the GI tract, from lumen to superficial?
Mucosa
Submucosa
Muscularis Externa
Serosa/Adventitia
***Serosa is covered by peritoneum, while Adventitia is retroperitoneal
In the GI tract, the ________ differs considerably from region to region. It reflects the functional activity.
Mucosa
The mucosal layer has three components, which are…
Lining Epithelium
Lamina Propria
Muscularis Mucosae
This layer of the mucosa consists of vascularized loose CT. It contains LNs, lymphocytes, plasma cells, and macrophages.
Lamina Propria
This layer of the mucosa consists of a thin layer of smooth muscle and controls the mobility of mucosa/mucosal glands.
Muscularis Mucosae
This layer of the GI tract consists of dense irregular CT with neurovasculature and lymphatics. Glands may be present (esophagus and duodenum).
Submucosal
This layer of the GI tract consists of two layers of smooth muscle, an inner circular layer and outer longitudinal layer.
Muscularis Externa
In the Muscularis Externa, contraction of the ________ layer constricts the lumen and contraction of the ________ layer shortens the tube.
Circular
Longitudinal
What resides between the layers of the Muscularis Externa (circular and longitudinal layers)?
Neurovascular Plexuses
When the digestive tube is suspended by a mesentery/peritoneal fold, the adventitia is covered by mesothelium forming the ________ layer.
Serosa
***Those without mesothelium have an adventitia!
T/F. Organs may have an adventitia and/or serosa, depending on location.
True
This type of mucosa is protective, and can be found in the oral cavity, pharynx, and anal canal.
Nonkeratinized Stratified Squamous
This type of mucosa is secretory. It is packed with glands and found in the stomach.
Simple Columnar Epithelium
This type of mucosa is absorptive. It is arranged as villi with crypts, and glands may be present (in small intestine).
Simple Columnar Epithelium
This type of mucosa is absorptive/protective. It is arranged into closely packed, glands (large intestine). Has extensive goblet cells.
Simple Columnar Epithelium
There are two plexuses of sensory and motor neurons, linked by interneurons, that provide intrinsic (enteric) innervation. What are these plexuses?
Submucosal Plexus of Meissner
Myenteric Plexus of Auerbach
This nerve plexus is between the inner circular and outer longitudinal layers of muscularis externa.
Myenteric Plexus of Auerbach
Responsive to local stimuli and input from ANS regulate and control what actions of the GI tract?
1) Peristaltic contractions of muscularis externa and movements of muscularis mucosae.
2) Secretory activities of the mucosal and submucosal glands.
__________ axons of the parasympathetics increase motility, while __________ axons of the sympathetics decrease motility.
Preganglionic
Postganglionic
This is a fibromuscular tube that conveys food from the oropharynx to the stomach.
Esophagus
Does the esophagus contain adventitia or serosa?
Both
Thoracic esophagus = Adventitia
Inferior to diaphragm = Serosa
Mucosal and submucosal glands produce a thin layer of mucus to lubricate the epithelium. ________ ________ ________ reside in the lamina propria of terminal esophagus, and _______ _______ consist of small lobules with mucous and serous cell types, drained by a single duct.
Cardiac Esophageal Glands
Submucosal Glands
What type of epithelium is the Mucosa of the Esophagus composed of?
Nonkeratinized Stratified Squamous
This layer of the esophagus overlies a lamina propria and has numerous folds.
Mucosa
***Muscularis Mucosae only present in lower segment!
This layer of the esophagus is a network of collagen and elastic fibers. There are many small blood vessels.
Submucosa