Best explanation of embryo of esophagus

1. HISTOLOGY OF GIT GENERAL PLAN
Anatomy &HISTOLOGY OF ESOPHAGUS

2. LERANING OBJECTIVES
• DESCRIBE THE GENERAL
HISTOLOGY OF GIT
• DESCRIBE THE HISTOLOGY OF
ESOPHAGUS
• CORELATE ANATOMY WITH
HISTOLGY OF ESOPHAGUS
• Relate histology with pathologies

13. I. General Structure
The lumen of the alimentary canal is lined by an epithelium,
deep to which is a loose connective tissue known as the
lamina propria.
richly vascularized connective tissue houses glands
lymph vessels and occasional lymphoid nodules.
Surrounding this connective tissue coat is the muscularis
mucosae, composed of an inner circular layer and an outer
longitudinal layer of smooth muscle.
epithelium, lamina propria, and muscularis
mucosae -mucosa.

15. Muscularis
• The thick muscularis is composed of
smooth muscle cells.

17. • The mucosa is also frequently called a
mucous membrane.

18. Submucosa
 Dense, irregular fibroelastic connective
tissue layer, the submucosa.
 Composed of dense connective tissue
with many blood and lymph vessels
 Submucosal (Meissner's) nerve
plexus. may also contain glands and
lymphoid tissue.

21. Muscularis externa
• The thick muscularis (or muscularis
externa) is composed of smooth muscle
cells organized astwo or more sublayers. In
the internal sublayer (closer to the lumen),
the fiber orientation is generally circular; in
the external sublayer it is longitudinal.

22. • The connective tissue between the muscle
sublayers contains blood and lymph vessels,
as well as the myenteric (Auerbach) nerve
plexus of many autonomic neurons
aggregated into small ganglia and
interconnected by pre- and postganglionic
nerve fibers.
• This and the submucosal plexus together
comprise the enteric nervous system of the

23. • Contractions of the muscularis, which mix
and propel the luminal contents forward, are
generated and coordinated by the myenteric
plexus.

25. Serosa adventitia
• thin layer of loose
connective tissue, rich in
blood and lymph vessels
and adipose tissue
• simple squamous covering
epithelium
(mesothelium).
• In the abdominal cavity,
the serosa is continuous
with the mesenteries (thin
membranes covered by
mesothelium on both
sides), which support the
intestines, and with the
• In places where the
digestive tract is not
suspended in a cavity but
bound directly to adjacent
structures, such as in the
esophagus , the serosa is
replaced by a thick
adventitia, a connective
tissue layer that merges
with the surrounding
tissues
• and lacks mesothelium.

26. Hirschsprung disease
• In diseases such as Hirschsprung disease
(congenital aganglionic megacolon) or Chagas
disease (trypanosomiasis, infection with the
protozoan Trypanosoma cruzi), plexuses in the
digestive tract’s enteric nervous system are absent or
severely injured, respectively.
• This disturbs digestive tract motility and produces
dilations in some areas.

29. ESOPHAGUS
GROSS ANATOMY AND
HISTOLOGY

30. Esophagus
• fibromuscular tube
that extends from
the pharynx to the
stomach.
• C6-T10

35. xtent
Thorax
• enters the superior
mediastinum
between the trachea
and the vertebral
column
•

36. Course
• descends from the superior
mediastinum
• into the posterior
mediastinum
passing posterior and to the
right of the arch of the aorta
and posterior to the
pericardium and left atrium.

37. • deviates to the left
• passes through the
esophageal hiatus in
the diaphragm at the
level of the T10
vertebra, anterior to
the aorta

38. Esophagus is compressed by three
structures
• the aortic arch,
• left main
bronchus
• diaphragm.

43. Portal systemic anastomosis
• Venous drainage primarily to the portal
venous system through the left gastric vein
,
• proximal thoracic part of the esophagus
drains primarily into the systemic venous
system through the esophageal veins
entering the azygos vein .
•

46. Lymphatic drainage
• left gastric lymph nodes, which in
turn drain mainly to the celiac
lymph nodes .

53. submucosa
Dense, fibroelastic connective
tissue
houses the esophageal glands
proper.
Tubuloacinar glands
produce a mucous
secretion.
Meisner’s submucosal plexus is
present in the submucosa.

54. Muscularis
externa
.
• upper third -skeletal
muscle;
• middle third -skeletal
and smooth muscle
• lowest third -smooth
muscle fibers.
• Auerbach’s plexus-
inner circular and
outer longitudinal
smooth muscle layers

55. until it pierces the
diaphragm, after which it
is covered by a serosa.

59. Transition of epithelium

60. Gastroesophageal reflux
disease is
• decrease in the lower
esophageal sphincter tone
or hiatus hernia.
• develops when the
mucosal defenses are not
sufficient to protect the
esophageal mucosa from
the acid, pepsin, and bile,
• symptoms
heartburn
• atypical chest pain

62. Achalasia of the Cardia
associated with a
degeneration of the
parasympathetic
plexus (Auerbach's
plexus) in the wall of
the esophagus.
• Dysphagia (difficulty in
swallowing)
• regurgitation
• proximal dilatation and
distal narrowing of the
esophagus