stomach histology

You are analyzing patterns of stem cell renewal and terminal differentiation in the GI tract. As part of your research, you generate monoclonal antibodies that identify specific populations of gastric epithelial cells. One of your antibodies recognizes a protease found in zymogen granules. Which of the following cells is characterized by the presence of zymogen granules?

1)Chief Cells pepsinogen-secreting, and gastric lipase-secreting cells

You are investigating the activation of smooth muscle in the muscularis mucosae of the stomach and its role in assisting outflow from gastric glands. The cell bodies for visceral motor fibers that innervate the muscularis mucosae are present in which of the following anatomic locations?

1)Meissner Plexus

The gastrointestinal epithelium undergoes renewal every __days

3 to 5

Gastroduodenal Junction Stomach to Duodenum mucosas?

Glandular mucosa of the stomach Villous absorptive-type mucosa of the duodenum

cardiac region cells glands secretes purpose

Mostly mucus cells Tubular, tortuous, & branched glands shorter than the fundic or pyloric glands Helps protect epithelium against gastric reflux using cardiac glands in esophagus and gastric juice

Due to cardiac gastric glands being primarily mucous, they can also be demonstrated using __ stain

PAS the cells lining the gastric pits stain very intensely with PAS due to the carbohydrate-rich, viscous mucus they secrete.

A patient presents to family medicine and describes a burning sensation after eating and points to their sternal area. The patient also describes noticing a sour taste in their mouth and hoarseness. The resident describes Gastroesophageal Reflux Disease (GERD) and orders an endoscopy, barium swallow and turns to you as the medical student. "What are we ruling out?"

Stricture, barretts, adenocarcimona, esophagitis

Mucous Cells

Surface Mucous cells: mucus cloudy and insoluble and protect Neck mucus cell: immature precursor, secrete less mucus, more soluble

Gastroesophageal Junction: H&E

The cardiac gastric glands are only present in a small segment of the stomach mucosa adjacent to the gastroesophageal junction

Neuroendocrine cells (also called Enteroendocrine cells and G cells) found where act as

base of fundus and pylorus chrmoreceptors (open)

Parietal cells have deep, branching .. have what pump

canaliculi. related to a tubulovesicular membrane complex, which is a system that consists of small, membrane-bound vesicles that include a transmembrane 'proton pump' in the form of a: H+-K+ ATPase

Remember the mucosal layer consists of the

epithelium, lamina propria, & muscularis mucosa!

Signet ring cell carcinoma (SRCC) produces?

highly malignant adenocarcinoma that produces mucin large vacuoles full of mucin that displace the nucleus to the cell's periphery

•stem cells in gastric mucosa

isthmus

Histologically, the stomach is divided into three regions, cardiac, pylorus, & fundus, based on the type of gland contained in the __regions

mucosal

pyloric area cell type function tubes

mucous cells (like surface mucous cells), with the occasional parietal and enteroendocrine cell Aids in the protection of pyloric mucosa Branched, coiled, tubular glands that empty into long pits that traverse about ½ the thickness of the mucosa (more extensive than in the cardiac or fundic regions)

cell type turnover rate mucous neck cell chief and G cell parietal cell

mucous neck cell 6 days chief and G cell 75 days parietal cell 175 days

in an empty contracted stomach, the mucosa is thrown into longitudinal folds (rugae) because of the contraction of the

muscularis mucosae

Chief/peptic/zymogenic cells secrete

pepsinogen-secreting, and gastric lipase-secreting cells and are in the deeper portion of the fundic glands

•Acid secretion ↑, canalicular system becomes more __ from fusion

prominent

Parietal cells secrete where in gland

secrete HCl and intrinsic factor •Distributed throughout the gland but are more numerous in the neck.

The fundic glands are present where?

throughout the entire gastric mucosa, except for small regions occupied by cardiac and pyloric glands

The muscularis externa is unique in the stomach as it is composed of three layers:

•Inner oblique layer •Middle circular layer Outer longitudinal layer (OCL)

cells in fundic area

•Mucous cells •Chief cells •Parietal cells •Enteroendocrine cells •Undifferentiated adult stem cells (From isthmus niche)

Chief cells characteristics

•Secretory vesicles or zymogen granules in the apical portion of the cell store pepsinogen after being synthesized by ribosomes Prominent rER

Mucosa contain epithelium

•simple columnar epithelium •relatively thick and contains numerous tubular glands. •contain gastric pits, where the gastric glands open into