GI A&P Flashcards
Review the old biomed and anatomy GI Lectures
:)
The esophageal mucosa is different than
the rest of the GI tract: it is composed of
thick, ______
stratified squamous epithelium
The esophagus passes through the ____
of the diaphragm
Esophageal Hiatus
As the esophagus connects to the stomach, the mucosa changes from
____ to secretory ____
squamous cells; columnar epithelium
What is the junction called where the mucosa of the esophagus changes?
Squamocolumnar Junction (important with GERD, cancer)
The Chyme in the stomach then passes
through the _____, a thick layer of smooth
muscle that regulates entry of material into the duodenum
Pyloric Sphincter
The stomach lining is composed of numerous fold called ____
Gastric Rugae
Pyloric stenosis can lead to____
projectile vomitting (babies)
What do the rugae do for the stomach?
allow the stomach to expand significantly when
food enters, and then return to the normal J-shape when it is empty again
Surface Mucous Cells secrete ____
mucin (Mucus)
Mucous Neck Cells also secrete ____ to
protect the gland itself from the acid.
mucin
Parietal Cells produce _____
which denatures proteins
Hydrochloric Acid (ph 2.0)
Chief Cells secrete ____- denatures proteins
Pepsinogen (which becomes
Pepsin)
Enterochromaffin-Like Cells (ECL Cells) secrete
_____, which activates Parietal Cells.
Histamine
D Cells secrete ______
somatostatin
____ is the first 25 cm of the small intestine
The Duodenum
Inside the villi are rich
networks of _____
capillaries composed of Venules,
Arterioles, and Lacteals
Explain why there is a countercurrent blood flow in the intestinal villi
the close proximity of arterial and
venous blood results in a shunting of oxygen, with up to 80% of oxygen bypassing the villi epithelium
Layers of the GI wall
○ Mucosa: is in contact with food, absorption of nutrients
○ Submucosa: contains blood vessels,
lymphatic vessels, and nerves
○ Muscularis
■ Longitudinal Smooth Muscle
■ Circular Smooth Muscle
○ Serosa: Protective connective Tissue
the primary region for
nutrient absorption
Jejunum
T/F the Jejunum and Illeum are both completely
intraperitoneal and is suspended in the abdomen by the mesentery
T
Importance of the ileocecal valve
Acts as a sphincter that
primarily prevents fecal contents
from the colon from going back
into the small intestines
Appendix characteristics
This intraperitoneal structure is thin,
hollow, and finger-like, lined by small
lymphatic nodules
This region is a common area of
inflammation with Crohn’s Disease
The Ileocecal Junction, and functionally is named the ileocecal Valve
the colon absorbs _____ from the remaining digested material.
water and electrolytes
_____ are fatty lobules that hang off the colon.
Epiploic appendages
_____ are bands of muscle that run
longitudinally along the colon
Teniae coli
The ____ is a muscular tube that
readily expands to store
accumulated fecal material prior
to defecation.
rectum
The neural sensation that suggests
the need for a bowel movement is
triggered by ______
expansion of the rectum
T/F the rectum is part of the intestines
T
____ are normal structures of the
anorectum
Hemorrhoidal Venous Cushions
What do Hemorrhoidal Venous Cushions do?
○ Serve to protect the anal sphincter, aid in closure of the anal canal,
and provide sensory information
○ Located in an area with many sensory nerve
endings
T/F Hemorrhoidal Venous Cushions are only present in adulthood
F - Present in utero and persist through adulthood
Part of the distal anastomosis between the
superior rectal arteries and the rectal veins
Hemorrhoidal Venous Cushions
Two main types of movements occur in the GI tract:
○ Propulsive Movements- Cause food products to move forward along the tract at an
appropriate rate to accommodate digestion and absorption.
○ Mixing Movements- Keep the intestinal contents thoroughly mixed at all times.
____ in particular increases GI motility.
Motilin
the purpose of gastrointestinal movement
to enhance digestion of ingested food products and to move food through
the GI tract to facilitate absorption and excretion of waste products.
Congenital absence of the myenteric plexus
(Hirschsprung’s Disease) results in the
inability to _____
produce peristaltic movements of
the intestines
Mixing movements and peristalsis both
require two things:
an intact Myenteric Plexus of the
Enteric Nervous System, as well as a fully
functional Autonomic Nervous System
The three main branches of the
Celiac Trunk are
○ Common Hepatic Artery
○ Left Gastric Artery
○ Splenic Artery
Immediately inferior to the Celiac Trunk
emerges the _____
Superior Mesenteric Artery.
Superior Mesenteric Artery supplies the blood to:
○ Most of the small intestine
○ The pancreas
○ The proximal half of the large
intestine
The branches of the Inferior Mesenteric Artery supply blood to the following tissues
○ The descending colon
○ The sigmoid colon
○ The rectum
The two main types of GI blood flow
modulators include:
○ Gut Activity / Metabolic Factors-
■ Release of vasodilators
■ Decreased O2 concentration
○ Nervous System Input-
■ Autonomic Nervous System
The _____ is a potential space
Peritoneal cavity
The ____ Peritoneum lines the inside surface
of the body wall
Parietal
The ____ Peritoneum covers the surface of
the internal organs
Visceral
_____: Pulling fluid from the peritoneal cavity to test (diagnostic) or drain excess fluid
(therapeutic)
Paracentesis
Accessory Digestive Structures include:
○ Liver
○ Gallbladder
○ Network of ducts
● The Pancreas
These Accessory organs and
structures produce _____
secretions that facility chemical digestion
The liver makes up __% of an adults body weight
2
When needed for digestion, Bile (from the liver
and gallbladder) and Digestive Enzymes (from
the pancreas) enter the duodenum via the ____
Major Duodenal Papilla
The pancreas is a retroperitoneal organ that is considered a mixed gland, meaning ____
it has both endocrine and exocrine functions
When Chyme (that contains fat and protein)
reaches the Duodenum, duodenal epithelial
cells secrete ____
Cholecystokinin (CCK)
CCK acts by
○ Triggering vagal nerve stimulation
○ Acting directly on the gallbladder with ACh
The Cystic Duct attaches to the ___ and carries bile to and from the
gallbladder
Common
Hepatic Duct
After the Cystic Duct and Common Hepatic Duct
merge to become the Common Bile Duct, the
Pancreatic Duct then merges as well, creating the _____
Hepatopancreatic Ampulla
