Digestive System Flashcards
Four Principal Layers of the GI tract:
Mucosa/mucous membrane
Submucosa
Muscularis / Muscularis externa
Serosa
Mucosa/mucous membrane
muscularis mucosa
Submucosa
ubmucosal nerve plexus / meissner’s nerve plexus
Muscularis / Muscularis externa
myenteric nerve plexus / auerbach’s nerve plexus
Serosa
mesothelium
columnar all over,
except in the esophagus
and the lower part of
anal canal where it is
stratified squamous.
EPITHELIUM
- Made up of collagen and reticular fibers.
- contain blood capillaries, lymph vessels and nerves
- In SI, the core of villus is attached to the lamina propria.
- Prominent aggregation of lymphatic tissue is seen in Lamina propria
LAMINA PROPRIA
At numerous places
epithelium dips into the
Lamina propria and form
crypts (Simple tubular glands).
Crypts
- Contraction of Muscularis
Mucosa is important for the local
mixing of intestinal contents - It changes the shape of mucosa,
that helps in absorption and
secretion
MUSCULARIS MUCOSAE
2 LAYER OF MUSCULARIS MUCOSAE
Inner layer
Outer layer
MUSCULARIS MUCOSAE
Inner layer _____
Outer layer _____
Circular
Longitudinal
The Digestive System
7 Digestive Tract
Oral cavity
Mouth
Esophagus
Stomach
Small Intestine
Large Intestine
Rectum
Anus
The Digestive System 4 Glands of the Digestive
system
Salivary Glands
Liver Glands
Pancreas
Gall bladder
A mass of striated muscle covered by
mucous membrane whose structure varies according
to the region
Tongue
4 types of papillae
- Filiform papillae
- Fungiform papillae
- Foliate papillae
- Circumvallate papillae
is both exocrine and endocrine organ that digest
food and secrete hormones; its main function is to continue
the digestion of CHO initiated in the mouth.
Stomach
32 permanent teeth
( 2 incisor; 1 canine; 2 premolars and
3 molars/quadrant); 20 deciduous teeth;
3 parts of the stomach
- Cardia
- Fundus/ Body
- Pylorus
- Epithelial lining at
the cardio-esophageal
junction - changes from
stratified sq. to
simple columnar - Mucous surface cells
and cardiac glands
Mucosa
Consists of blood vessels, lymphatic vessels and Meissner’s
plexus.
SUBMUCOSA
3 Muscularis externa
Inner – Oblique
Middle – circular
Outer – longitudinal
Outermost layers of the stomach which consists of loose
connective tissue
Serosa
Inner –
Middle –
Outer –
Oblique
circular
longitudinal
Lining Epithelium –
Simple columnar,
invaginates to various
extents into the lamina
propria, forming _____
gastric
pits.
Secretes HCL and intrinsic factor
Parietal or oxyntic cells
Secrete pepsinogen which is
converted into pepsin in an acid environment
Chief or zymogenic cells
Produces soluble mucus
Mucous neck cells
is the site of terminal food digestion,
metabolic absorption and endocrine secretion.
Small intestines
Small tubular fundic/gastric glands are present.
Lamina Propria
: Secretes serotonin,
histamine and gastrin
Enteroendocrine and APUD cells
3 segments of Small intestines
enum; Jejunum;Ileum
Small Intestines 3 Mucous membrane
- Plicae Circulares/Kerckring’s Valve
- Intestinal villi
- Glands of Lieberkuhn/ crypts/ intestinal glands
4 Cells found in the
small intestines
- Absorptive cells (Enterocytes)
- Goblet cells
- Paneth cells
- M cells/ membranous epithelial cells
rich in lymphoid cells and nodules
Lamina propia –
longitudinal and circular strands
Muscularis
–small pendolous protuberances
composed of adipose tissues in the serous layer of the
intraperitoneal part of large intestines
Appendices epiplocae
3 thick longitudinal bands of the outer
layer
Taenia coli
series of longitudinal
folds in the mucous membrane of the anal region
Rectal columns of Morgagni
Anal Canal 3 Epithelium
upper part-simple columnar
middle part-stratified squamous non-keratinized
lower part-covered by true skin
Small mucosal folds between the anal columns ____
-Pectinate
line.
upper part-
middle part-
lower part-
simple columnar
stratified squamous non-keratinized
covered by true skin
Muscularis externa- circular muscle forms involuntary
_________
internal anal sphincter.
*Produce digestive enzymes that acts in the small intestines
*Secretes hormones insulin and glucagon into the blood
stream
Pancreas
*Absorbs water from the bile and stores the bile in
concentrated form
Gall bladder
*Wet and lubricate the oral cavity and its contents
*Initiates digestion of CHO
*Secrete substances such as IgA, lysozymes and lactoferrin
Saliva ry Glands
*Produce bile – digestion of fat
*Plays a role in the lipid, CHO and CHON metabolism
*Inactivates and metabolizes many toxic substances and
drugs
*Iron metabolism
*Synthesis of blood protein and factors necessary for blood
coagulation
Liver Glands
