This document summarizes the structure and histology of the esophagus and stomach. It describes the esophagus as a muscular tube that transports food from the pharynx to the stomach. It has a star-shaped lumen and contains stratified squamous epithelium. The stomach is a bean-shaped organ involved in digestion that has four anatomical regions and three histological regions. It contains gastric pits and various gland types, including cardiac, fundic and pyloric glands that secrete mucus and enzymes to aid in digestion. The document also describes the layers of the esophagus and stomach, including the mucosa, submucosa, muscularis externa and serosa.

2. about 25-cm -long muscular tube
function : forwarding swallowed food from
the pharynx down into the stomach
its lumen is star -shaped, due to the
longitudinal reserve folds
the typical structure of the alimentary canal
appears in this segment

3. epithelium (lamina epithelialis mucosae):
stratified, nonkeratinized squamous
epithelium at its entire length
lamina propria mucosae comprises cardiac
esophageal glands (glandulae oesophageae
cardiacae) in its begining and terminal
portions; these glands resemble the cardiac
glands, hence the name

4. cardiac esophageal glands produce neutral mucin,
which protects the cells against the possible reflux
of gastric juice
in the lamina propria, there are scattered lymphatic
elements, frequently in the vicinity of the excretory
ducts
lamina muscularis mucosae is composed of mainly
longitudinal smooth muscle cells

5. is thrown into longitodinal folds, just like
mucous membrane
there are mixed or purely mucous small
salivary glands, which are called esophageal
glands proper (glandulae oesophageae
propriae)

6. in the upper one-third, striated muscle can be
found, only
in the middle approximately one-third
segments, the striated and smooth muscles
are intermingled
in the lower one-third, there are smooth
muscle cells, only

7. tunica adventitia is the outermost main layer
of the esophagus; this layer connects the
majority (cervical and thoracic portions) of
the organ to the surrounding tissue
the abdominal portion , however , is replaced
by tunica serosa (serous membrane)

10. bean -shaped hollow muscular organ of the
gastro -intestinal tract involved in the second
phase of digestion
it has four anatomical parts: cardia, fundus,
body and pylorus
it has three histological distinct parts: (1)
cardia, (2) the fundus and the body have the
same histological properties, (3) pylorus

11. simple columnar epithelium invaginates
into the lamina propria, thereby it makes
gastric pits (foveolae gastricae)
the tubular glands (cardiac -, fundic- and
pyloric glands) of stomach empty into the
bottom of the gastric pits
the epithelial cells produce thick , neutral
mucin , which protects the cells themselves
from highly acidic gastric juice

12. loose connective tissue, which may contain
many lymphocytes
all the gastric glands are located in this lamina
in the three histological portions of the
stomach the glands display somewhat
different morphology ; their products are also
different

13. a lamina muscularis mucosae
well-developed, usually is composed of two sublayers
of smooth muscle cells

14. loose coonecting tissue, containing
blood vessels
lymphatics
lymphocytes
solitary fat cells
macrophages
mast cells

15. contains smooth muscle cells
composed of sublayers:
outermost sublayer : discontinuous; comprise mainly
longitudinally oriented smooth muscles cells, which may
be absent from areas within the pyloric portion
middle sublayer : circularly arranged smooth muscle cells,
well-developed throughout the stomach ; the middle
sublayer is greatly enhanced in the pyloric portion , where
it is called pyloric sphincter muscle
innermost sublayer : oblique bundles of smooth muscle
cells may occur

16. The stomach is an intraperitoneal organ . Its
outermost main layer is a serous membrane
of loose coonective tissue and mesothelium
towards the peritoneal cavity .

17. located in the lamina propria, which are
different in the histological portions:
cardiac glands
fundic glands
pyloric glands

18. simple or branched glands, located in the cardiac
portion
the secretory cells resemble the surface mucous cells
of the gastric pits
produce mucin

21. branched tubular glands
several glands open into one gastric pit
have segments
in the upper segment ( neck )
neck mucous cells
undifferentiated stem cells
in the middle and lower segments (principal
segment )
H Cl-producing parietal cells
chief cells, which secrete pepsinogen
enteroendocrine cells

24. in the pyloric region , the gastric pits are
deeper than in the other ones
the pyloric glands are branched tubular
glands with curved ends
the secretory cells stain lightly
they produce mucin and antibacterial
lysozyme
entero -endocrine cells are also present