Main structures of
GI tract
The 6 basic
process in
digestion
Four layers of GI
tract, from deep to
superficial: mucosa,
submucosa,
,muscularis, and
serosa
Layers of the gastrointestinal (GI) tract
• Mucosa. Consists of
• Layer of epithelium in direct contact with contents of the GI tract
• Thin layer of connective tissue
• Thin layer of smooth muscle that can create folds to increase surface area.
• The mucosa also contains prominent lymphatic nodules to make an immune res
• Submucosa.
• Connective tissue that binds mucosa to muscularis.
• Also contains blood and lymphatic vessels that receive absorbed food molecules
,• Also contains networks of nerves regulated by autonomic nervous system (ANS)
enteric nervous system (ENS). ENS nerves control secretions of organs of GI trac
Layers of gastrointestinal (GI) tract
Muscularis. Has a circular muscle layer and longitudinal muscle layer
help digestion and propel food. Except for pharynx, muscle layer is
smooth muscle cells. ENS neurons within the muscularis control
frequency and strength of its contractions.
Serosa and peritoneum. The serosa, is the outermost layer around
organs of GI tract. It is a membrane that secretes a slippery, watery
fluid that allows the tract to glide easily against other organs. Also
called the visceral peritoneum.
, Nervous system
of the gut
10% of bodies nerves
are in gut
GI tract
The 6 basic
process in
digestion
Four layers of GI
tract, from deep to
superficial: mucosa,
submucosa,
,muscularis, and
serosa
Layers of the gastrointestinal (GI) tract
• Mucosa. Consists of
• Layer of epithelium in direct contact with contents of the GI tract
• Thin layer of connective tissue
• Thin layer of smooth muscle that can create folds to increase surface area.
• The mucosa also contains prominent lymphatic nodules to make an immune res
• Submucosa.
• Connective tissue that binds mucosa to muscularis.
• Also contains blood and lymphatic vessels that receive absorbed food molecules
,• Also contains networks of nerves regulated by autonomic nervous system (ANS)
enteric nervous system (ENS). ENS nerves control secretions of organs of GI trac
Layers of gastrointestinal (GI) tract
Muscularis. Has a circular muscle layer and longitudinal muscle layer
help digestion and propel food. Except for pharynx, muscle layer is
smooth muscle cells. ENS neurons within the muscularis control
frequency and strength of its contractions.
Serosa and peritoneum. The serosa, is the outermost layer around
organs of GI tract. It is a membrane that secretes a slippery, watery
fluid that allows the tract to glide easily against other organs. Also
called the visceral peritoneum.
, Nervous system
of the gut
10% of bodies nerves
are in gut
