Gastro-Intestinal Anatomy (part I) Flashcards
The GI tract is derived from what germ layer
the endoderm
what are the three embryological parts of the GI tract
Foregut, midgut and hindgut
the fore gut is supplied by what
celiac trunk
what does the foregut give rise too
esophagus, stomach, proximal half of the duodenum, the liver, gallbladder, and pancreas
what is the midgut supplied by
superior mesenteric artery
what does the midgut give rise too
distal half of the duodenum, small intestine, proximal half of large intestine up to the proximal two thirds of transverse colon
what is the hindgut supplied by
the inferior mesenteric artery
what does the hindgut give rise too
rest of the large intestine from the distal third of the transverse colon to the proximal half of the anal canal
What is Meckel’s diverticulum
it is an uncommon congenital anomaly
what percentage of the population does meckels diverticulum occur in
2%
how long is Meckels diverticulum and where is it located
it is 2 inches long and is located 2 feet proximal to the ileocecal junction
what are the two types of ectoptic tissues that meckels diverticulum may contain
gastric and pancreatic tissue
how much more often is meckels diverticulum found in males than females
two times more common in males
The GI tract can be divided in how many quadrants? what are they
4 quadrants - right and left upper and right and left lower quadrants
how many regions are located in the abdominal region
9 regions associated with organs
what are the 9 regions of the abdominal area
epigastric, right and left hypochondrium, umbilical, right and left flanks, right iliac fossa, left iliac fossa and hypogastric (suprapubic)
what organs are in the epigastric region of the abs
stomach duodenum and pancreas
what organs are in the right hypochondrium region
liver and gallbladder
what organs are in the left hypochondrium region
spleen
what is located in the umbilical region of the abs
small intestine
what organs are located in the right and left flanks of the abs
right and left kidneys
What organs are located in the right iliac fossa of the abs
appendix, right ovary and right uterine tube and cecum
what organs are located in the left iliac fossa of the abs
left ovary, left uterine tube and sigmoid colon
what organs are located in the hypogastric (suprapubic) region
bladder and uterus
Where is the dermatome T7 level
xiphoid level
where is the dermatome T10 level
umbilical level
where is the dermatome level of L1
inguinal region
how many layers does the anterior abdominal wall consist of
6 layers
what are the 6 layers of the anterior abdominal wall
Skin Subcutaneous tissue muscle transversalis fascia extraperitoneal fat parietal peritoneum
the subcutaneous layer of the anterior abdominal wall is further divided into how many layers and what are they
two more layers fatty layer (camper) membranous layer (Scarpa)
the membranous layer of the subcutaneous layer of the anterior abdominal wall is continuous of with
Colles fascia in the scrotum and buck’s fascia around the penis
the membranous layer of the subcutaneous tissue of the anterior abdominal wall is attaches to what
the base of the urogenital diaphragm
In the muscle layer lateral to the linea semilunaris of the anterior abdominal wall there are three muscles. What are they
External oblique
internal oblique
transversalis abdominal
in the muscle layer medial to the linea semilunaris there are three different structures. What are they
Anterior layer of the rectus sheath
rectus abdominis muscle
posterior layer of the rectus sheath
The anterior abdominal wall is innervated by what
the lower 5 intercostal nerves (T7-T11), the subcostal nerve (T12), the iliohypogastric and ilioinguinal nerves (L1)
Where is the rectus sheath found in relation to the arcuate line
above and below
the rectus sheath above the arcuate line has what two layers
Anterior and posterior layer
the rectus sheath below the arcuate line consists of that layers
anterior layer and posterior layer
the posterior layer of the rectus sheath below the arcuate line is what
deficient and is covered only by transversalis fascia
the arcuate line is located where
posterior to the rectus muscle midway between the umbilicus and the symphysis
what are the contents of the rectus sheath
rectus abdominis muscle
pyramidalis muscle
superior and inferior epigastric arteries and veins
the Peritoneum is the what of the abdominal cavity
it is the inner lining
what are the two parts of the anterior abdominal wall peritoneum
the parietal and visceral layer
the parietal layer of the peritoneum of the anterior abdominal wall is what to pain
sensitive to pain
is the visceral layer of the peritoneum of the abdominal layer sensitive to pain
it is not sensitive to pain but is sensitive to distension
what are the two layers of the abdominal cavity
greater and lesser sacs
the lesser sac of the abdominal cavity lies where
behind the stomach
where does the lesser sac of the abdominal cavity open into
the greater sac via the epiploeic foramen of winslow
what are the retroperitoneal structure of the abdominal cavity (AC DC PARK AID)
Ascending Colon, Descending Colon, Pancreas, Adrenals, Rectum (lower 2/3), Kidneys, Aorta, IVC, Duodenum (2nd and 4th part)
The stomach is a J-shaped sac that is lined by what?
lined by columnar epithelium and covered by three layers of smooth muscle
what are the three layers of smooth muscle that are lining the stomach
Outer longitudinal
inner circular
innermost oblique
The stomach has 2 notches. What are they
cardiac and angular notches
the stomach has two curvatures known as what
lesser and greater curvature
what are the two attached omenta of the stomach
Greater and lesser omentum
the stomach is guarded by two sphincters known as what
lower esophageal and pyloric
the stomach contains two main types of cells. What are they and what do they produce
Chief cells - pepsinogen
parietal (oxyntic) cells - HCL and Intrinsic factor
What are the vessels that supply the stomach with blood
Left and Right Gastric
Left gastro-epiploic and short gastric
Right gastro-epiploic
The duodenum is shaped like what
a ten inch C-shaped tube
How many parts are there to the duodenum and what is their length?
4 parts 1st part is 2" long 2nd part is 3" long 3rd part is 4" long 4th part is 1" long
The upper half of the duodenum is supplied by what artery
the superior pancreatico-duodenal artery
the lower half of the duodenum is supplied by what artery
the inferior pancreatic-duodenal artery (the first branch of the superior mesenteric artery)
What opens up into the second part of the duodenum
the common bile duct of the biliary tree
what passes over the third part of the duodenum
the superior mesenteric vein and artery
The fourth part of the duodenum is continuous with the jejunum where
the duodeno-jejunal junction
The duodeno-jejunal junction is fixed and held in place by what
the suspensory ligament (of Treitz)
the suspensory ligament [of Treitz] (at the duodeno-jejunal junction) is attached to what
the right crus of the diaphragm
the first inch of the first part of the duodenum is what
intraperitoneal
the rest of the duodenum after the first inch of the first part is what
retroperitoneal
