 Anatomical regions of the Greater and Lesser Omentum
o Anatomy of Abdominopelvic Cavity ppt (slides 17-18).; Gilroy 144149,159; Moore 219
o Greater Omentum
 Four layered “apron” of peritoneum that attaches to the greater
curvature of the stomach.
 It its normal position, it covers most of the abdominal viscera, anteriorly.
 Includes three continuous ligaments/parts:
****not covered in lecture and not on exam****
 Gastrophrenic
o Connects inferior surface of the diaphragm to the stomach
 Gastrosplenic
o Connects spleen to stomach
 Gastrocolic
o “Apron” portion, connects from the greater curvature of the
stomach, descends, turns under, and ascends to the
transverse colon.

o Lesser Omentum
 Double layered peritoneum that connects lesser curvature of the
stomach/proximal duodenum to the liver.
 Space posterior to lesser omentum=omental bursa(lesser sac)
 The omental foramen travels from right to left, posterior to the
hepatoduodenal ligament, connecting the greater sac to the lesser.
****not covered in lecture and not on exam****
Includes continuous two parts/ligaments:
 Hepatogastric
o Connects lesser curvature of stomach to the liver
 Hepatoduodenal
o Connects lesser curvature of stomach to duodenum
o Contains the portal triad
 Portal vein, hepatic artery, and bile duct
o Oral quiz questions
 What organ is the greater and lesser Omentum attached to and be specific
about its location.
 A: Greater Omentum is attached to the greater curvature of the
Stomach. The Lesser Omentum is attached to the lesser curvature
of the Stomach.
 What can be found within the lesser Omentum that comes off the gall
bladder?



A: Common bile Duct, Right/Left branch of the hepatic artery, and
the hepatic artery itself.
What ligaments are found within the lesser Omentum?
 A: The Hepato-duodenal ligament and the Hepato-gastric ligament
 Branches of the Splenic artery

o Gilroy 210-211; Moore 264-265
o Largest branch of the celiac trunk, travels along the superior border of
the pancreas posterior to omental bursa but anterior to left kidney.
o Branching:
 Celiac trunk
 Splenic a.
o Left Gastroomental a. (Gastroepiploic)
 Main branch of splenic a.
 Travels along greater curvature of the stomach
o Prancreatic Branches
 Multiple branches
****the below branches are not covered in lecture and not on exam****
o Short Gastric a.
 Superior greater curvature of the stomach
o Posterior Gastric
 Branches of the Common Hepatic artery (2 Questions)
o Moore 324,326; Gilroy 210-211
o Branching:
 Celiac Trunk
 Common Hepatic a.
o Proper Hepatic a.
Left common hepatic a.
Right common hepatic a.
 Cystic a.
o Right Gastric a.
 Lesser curvature of stomach
o Gastroduodenal a.
****the below branches are not covered in lecture and not on exam****






Right Gastroomental a. (Gastroepiploic)
 Right part of the greater curvature of the
stomach
Anterior Superior Pancreaticoduodenal a.
Posterior Superior Pancreaticoduodenal a.
 Arterial blood flow to the Adrenal glands (p296 Moore)
This material will not be covered in lecture at this level of detail. Just suprarenal arteries as paired
branches from the abdominal aorta is enough. Likewise major suprarenal veins. This is extra more
detailed info.
o




Renal Arteries and Veins.
The renal arteries arise at the level of the IV disc between the L1 and L2
vertebrae. The longer right renal artery passes posterior to the IVC. Typically,
each artery divides close to the hilum into five segmental arteries that are end
arteries (i.e., they do not anastomose significantly with other segmental arteries,
so that the area supplied by each segmental artery is an independent, surgically
resectable unit or renal segment). Segmental arteries are distributed to the renal
segments as follows
The superior (apical) segment is supplied by the superior segmental artery;
the antero-superior and antero-inferior segments are supplied by the anterosuperior segmental and antero-inferior segmental arteries; and the inferior
segment is supplied by the inferior segmental artery. These arteries originate
from the anterior branch of the renal artery.
The posterior segmental artery, which originates from a continuation of the
posterior branch of the renal artery, supplies the posterior segment of the
kidney.
Multiple renal arteries are common and usually enter the hilum of the kidney.
Extra hilar renal arteries from the renal artery or aorta may enter the external
surface of the kidney, commonly at their poles. Several renal veins drain each
kidney and unite in a variable fashion to form the right and left renal veins. The
right and left renal veins lie anterior to the right and left renal arteries. The
longer left renal vein receives the left suprarenal vein, the left gonadal
(testicular or ovarian) vein, and a communication with the ascending lumbar
vein, then traverses the acute angle between the SMA anteriorly and the aorta
posteriorly. Each renal vein drains into the IVC
o

o

Suprarenal Arteries and Veins.
The endocrine function of the suprarenal glands makes their abundant blood
sup-ply necessary. The suprarenal arteries branch freely before entering each
gland so that 50–60 branches penetrate the capsule covering the entire surface
of the glands. Suprarenal arteries arise from three sources:
 Superior suprarenal arteries (6–8) from the inferior phrenic arteries.
 Middle suprarenal arteries (≤1) from the abdominal aorta near the level
of origin of the SMA.
 Inferior suprarenal arteries (≤1) from the renal arteries.
Venous Drainage
The venous drainage of the suprarenal glands occurs via large suprarenal veins.
The short right suprarenal vein drains into the IVC, whereas the longer left
suprarenal vein, often joined by the inferior phrenic vein, empties into the left
renal vein.
 External and Internal anatomy of the Stomach (p231 Moore)
o ***This material will not be covered in lecture at this level of detail***.
o The size, shape, and position of the stomach can vary markedly in persons
of different body types (bodily habitus)and may change even in the same
individual as a result of diaphragmatic movements during respiration, the
stomach’s contents (empty vs. after a heavy meal), and the position of the
person. In the supine position, the stomach commonly lies in the right and
left upper quadrants, or epigastric, umbilical, and left hypochondrium and
flank regions (Fig. 2.36A). In the erect position, the stomach moves
inferiorly. In asthenic (thin, weak) individuals, the body of the stomach
may extend into the pelvis (Fig. 2.36B).The stomach has four parts (Figs.
2.36A and 2.37A–C):
o Cardia:
 The part surrounding the cardial orifice, the superior opening or inlet of
the stomach. In the supine position, the cardial orifice usually lies
posterior to the 6th left costal cartilage, 2–4 cm from the median plane at
the level of the T11 vertebra.
o Fundus:
 The dilated superior part that is related to the left dome of the diaphragm
and is limited inferiorly by the horizontal plane of the cardial orifice. The
cardial notch is between the esophagus and the fundus. The fundus
maybe dilated by gas, fluid, food, or any combination of these. In the
supine position, the fundus usually lies posterior to the left 6th rib in the
plane of the MCL (Fig. 2.36A).
o Body:
 the major part of the stomach between the fundus and pyloric antrum.
o Pyloric part:
 the funnel-shaped out flow region of the stomach; its wider part, the
pyloric antrum, leads into the pyloric canal, its narrower part (Fig. 2.37A–
E). The pylorus (G., gatekeeper) is the distal, sphincteric regionof the
pyloric part. It is a marked thickening of the circular layer of smooth
muscle that controls discharge of the stomach contents through the
pyloric orifice (inferior opening or outlet of the stomach) into the
duodenum(Fig. 2.37D). Intermittent emptying of the stomach
occurswhen intragastric pressure overcomes the resistance of
thepylorus. The pylorus is normally tonically contracted sothat the
pyloric orifice is reduced, except when emitting chyme (semifluid mass).
At irregular intervals, gastricperistalsis pushes the chyme through the
pyloric canal and orifice into the small intestine for further mixing,
digestion, and absorption.
 In the supine position, the pyloric part of the stomach lies at the level of
the transpyloric plane, midway between the jugular notch superiorly and
the pubic crest inferiorly (Fig. 2.36A).


*** This material will not be covered in lecture and not on exam.***
The plane transects the 8th costal cartilages and the L1 vertebra. When
erect its location varies from the L2 through L4 vertebra. The pyloric
orifice is approximately 1.25 cm right of the midline. The stomach also
features two curvatures (Fig. 2.37A–C):
o Lesser curvature:
 forms the shorter concave right border of the stomach. The
angular incisure (notch), the most inferior part of the curvature, indicates
the junction of the body and pyloric part of the stomach (Fig. 2.37A &B).
The angular incisure lies just to the left of the midline.
o Greater curvature:
 forms the longer convex left border of the stomach.*** This material will not
be covered in lecture.*** It passes inferiorly to the left from the junction of
the 5th intercostal space and MCL, then curves to the right, passing deep
to the 9th or 10th left cartilage as it continues medially to reach the
pyloric antrum****.
Because of the unequal lengths of the lesser curvature on the right and
the greater curvature on the left, in most people the shape of the stomach
resembles the letter J.

o Interior Stomach:
 The smooth surface of the gastric mucosa is reddish brown during life,
except in the pyloric part, where it is pink. In life, it is covered by a
continuous mucous layer that protects its surface from the gastric acid
the stomach’s glands secrete. When contracted, the gastric mucosa is
thrown into longitudinal ridges or wrinkles called gastric folds(gastric
rugae)(Fig. 2.38A & B);

***This material will not be covered in lecture.***
they are most marked toward the pyloric part and along the greater
curvature. During swallowing, a temporary groove or furrow-like gastric
canal forms between the longitudinal gastric folds along the lesser
curvature. It can be observed radiographically and endoscopically. The
gastriccanal forms because of the firm attachment of the gastricmucosa to
the muscular layer, which does not have an obliquelayer at this site.
Saliva and small quantities of masticated food and other fluids drain
along the gastric canal to the pyloric canal when the stomach is mostly
empty. The gastric folds diminish and obliterate as the stomach is
distended (fills)****.
o
Layering of stomach musculature more important than most of this detail.
 Similarities and Anatomical Differences between jejunum and ileum
(pg.244 Moore)
Characteristics of jejunum and ileum – please refer to pic’s in Moore p. 244
Characteristic
Color
Caliber
Wall
Vascularity
Vasa Recta
Arcades
Fat in mesentery
Circular folds
Lymphoid nodules
Jejunum
Deeper Red
2-4 cm
Thick and heavy
Greater
Long
A few large loops
Less
Large, tall and closely
packed
Few
Ileum
Paler pink
2-3 cm
Thin and light
Less
Short
Many short loops
More
Low and sparse, absent
in distal parts
Many
 Hepatic Portal system
o The hepatic portal system shunts oxygenated blood from the abdominal
aorta to the liver, and it shunts deoxygenated blood from the small
intestine (via the superior mesenteric vein) and large intestine (via
inferior mesenteric vein) to the hepatic portal vein which sends collected
nutrients to the liver for processing.
 Branches of the Abdominal Aorta (2 Questions)
o Inferior phrenic
o Celiac Trunk
 Left gastric
 Splenic
 Short gastric (don’t worry to much about these branches. Refer
to textbook and notes)
 Splenic
 Left gastroepiploic
 Hepatic
 Right hepatic
o Cystic
 Left hepatic


Right gastric
Gastroduodenal
o Right gastroepiploic
o Renal aa
 Inferior suprarenal artery
o Superior Mesenteric
 Inferior pancreaticoduodenal
 Middle colic
 Right colic
 Intestinal a
 ileocolic
o Inferior Mesenteric
 Left colic
 Sigmoidal
 Superior rectal
o Lumbar aa (4 pairs)
***This material will not be covered in lecture and not on exam***.
 Branches of the Internal Iliac aa.
o
o
o
o
o
o
o
o
o
o
Iliolumbar
Superior Gluteal a
Lateral sacral
Umbilical
 Superior vesical
 Artery to ductus deferens (males)
Obturator
Inferior vesical
Middle rectal
Internal pudendal
 Inferior rectal
Inferior gluteal
(Uterine a. and Vaginal a. in females)***
 Blood flow to the Intestines  (Moore pg 250.)
Origin
Abdominal Aorta
Artery
Superior Mesenteric
Distribution
Part of GI tract from midgut
Superior Mesenteric
Intesinal (jejunal/ileal)
Middle colic
Right colic
Ileocolic
Ileococlic artery
Abdominal Aorta
Appendicular
Inferior mesenteric
Inferior Mesenteric
Left colic
Sigmoid
Superior rectal
Internal Iliac
Internal pudendal
Middle rectal
Inferior rectal
Jejunum/Ileum
Transverse colon
Ascending colon
Ileum, cecum, ascending
colon
Appendix
Supplies part of digestive
tract derived from hindgut
Descending colon
Descending and sigmoid
colon
Proximal part of rectum
Midpart of rectum
Distal part of rectum and
anal canal
 Ligaments of the Liver ****This is in more detail than you will be expected
to know****
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The falciform ligament is a broad and thin antero-posterior peritoneal fold,
falciform in shape, its base being directed downward and backward, its apex
upward and backward. It is situated in an antero-posterior plane, but lies obliquely
so that one surface faces forward and is in contact with the peritoneum behind the
right Rectus and the diaphragm, while the other is directed backward and is in
contact with the left lobe of the liver. It is attached by its left margin to the under
surface of the diaphragm, and the posterior surface of the sheath of the right Rectus
as low down as the umbilicus; by its right margin it extends from the notch on the
anterior margin of the liver, as far back as the posterior surface. It is composed of
two layers of peritoneum closely united together. Its base or free edge contains
between its layers the round ligament and the parumbilical veins.
The coronary ligament consists of an upper and a lower layer. The upper layer is
formed by the reflection of the peritoneum from the upper margin of the bare area
of the liver to the under surface of the diaphragm, and is continuous with the right
layer of the falciform ligament. The lower layer is reflected from the lower margin of
the bare area on to the right kidney and suprarenal gland, and is termed
the hepatorenal ligament.
The triangular ligaments (lateral ligaments) are two in number, right and left.
The right triangular ligament is situated at the right extremity of the bare area,
and is a small fold, which passes to the diaphragm, being formed by the apposition
of the upper and lower layers of the coronary ligament. The left triangular
ligament is a fold of some considerable size, which connects the posterior part of
the upper surface of the left lobe to the diaphragm; its anterior layer is continuous
with the left layer of the falciform ligament.

The round ligament (ligamentum teres hepatis) is a fibrous cord resulting from the
obliteration of the umbilical vein. It ascends from the umbilicus, in the free margin
of the falciform ligament, to the umbilical notch of the liver, from which it may be
traced in its proper fossa on the inferior surface of the liver to the porta, where it
becomes continuous with the ligamentum venosum.
 Structures of the porta hepatis (p. 270—Moore)
The porta hepatis is a transverse fissure where all the following that supply/drain the liver enter
and leave:

Vessels—hepatic portal vein (entering), hepatic artery (entering) and lymphatics


Hepatic nerve plexus
common hepatic bile ducts (leaving)
 Synthesis and Flow of Bile ****This is in more detail than you will be
expected to know****
The term biliary tree is derived from the arboreal branches of the bile ducts.
The bile produced in the liver is collected in bile canaliculi, which merge to form bile ducts. Within
the liver, these ducts are called intrahepatic (within the liver) bile ducts, and once they exit the liver
they are considered extrahepatic (outside the liver). The intrahepatic ducts eventually drain into
the right and left hepatic ducts, which merge to form the common hepatic duct. The cystic duct from
the gallbladder joins with the common hepatic duct to form the common bile duct.

Bile can either drain directly into the duodenum via the common bile duct, or be temporarily
stored in the gallbladder via the cystic duct. The common bile duct and the pancreatic
duct enter the second part of the duodenum together at the ampulla of Vater.
*This is extra info that will most likely not be tested on*

Blood Flow through the Kidney (Gilroy Pg 176-179, 208-209/ Moore Pg 290-
300)
Abdominal Aorta  Renal Artery  Segmental Artery  Lobar Artery  Interlobar Artery
 Arcuate Artery  Interlobular Artery  Afferent Arteriole  Glomerulus  Efferent
Arteriole  Peritubular Capillaries  Interlobular Vein  Arcuate Vein  Interlobar Vein
 Renal Vein  Inferior Vena Cava
 Internal macroscopic anatomy of the kidney
There are 3 layers of the kidney
1. Renal capsule
2. Renal cortex
3. Renal medulla
If the front half of the kidney is removed you can see it divided into three regions.
The most external region is the renal cortex numerous tubes and blood vessels located in
the cortex. Deep to the cortex is the renal medulla. This area is filled with renal pyramids.
The expanded base of a pyramid lies adjacent to the cortex and the papilla is oriented
toward the medial side of the kidney. Numerous tubules and ducts make up the pyramids.
Next to the medulla is the renal sinus. This medial pocket contains the large blood vessels
that pass in and out of the kidney and the tubes that conduct urine to the ureters and
bladder.
Describe the dual autonomic innervation of the kidneys, the ureters, bladder and the
adrenal glands. (Refer to Gilroy pgs. 245 – 247.)
***Review from from previous exam***
PARASYMPATHETIC INNERVATION TO KIDNEYS, URETERS, ADRENAL GLANDS



Preganglionic fibers from S2, 3, 4 unite to form Pelvic splanchnic nerves.
Synapse with postganglionic neurons in the hypogastric plexus.
Postganglionic fibers Ureters and Internal urethral sphincter = Initiate micturition
reflex.
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

Preganglionic fibers from the dorsal motor nucleus of CNX  the vagus nerve.
Synapse with postganglionic neurons in renal plexus.
Vasodialtion of renal aa. Increased GFRIncreased urine output.
SYMPATHETIC INNERVATION TO ADRENAL GLANDS




Preganglionic neurons in lateral horn of gray matter at spinal cord levels T5 – T9.
Preganglionic fibers travel as Greater thoracic splanchnic nerves THROUGH Celiac
ganglion.
Synapse with postganglionic neurons = CHROMAFFIN CELLS in adrenal medulla.
Chromaffin cells release epinephrine and norepinephrine into blood stream.
SYMPATHETIC INNERVATION TO KIDNEYS AND URETERS




Preganglionic neurons in lateral horn of gray matter at spinal cord level T12.
Preganglionic fibers travel as Least splanchnic nerve to aorticorenal ganglion.
Postgangionic fibers move through renal plexus to renal aa.
Vasoconstriction of renal aa. Decreased GFRDecreased urine output.
SYMPATHETIC INNERVATION TO BLADDER/INTRENAL URETHRAL SPHINCTER



Preganglionic neurons in lateral horn of gray matter at spinal cord levels L1-L2.
Preganglionic fibers travel as Lumbar splanchnic nerves to Hypogastric plexus.
Synapse with postganglionic neuronsInduce contraction of Internal urethral
sphincter.
Gilroy Pg 176-179, 208-209
Moore Pg 290-300
. Name the organs that comprise the hindgut.
- Distal ½ of the transverse colon, descending colon, sigmoid colon, and rectum
2. Identify the vessels that supply blood to the rectum and the arteries from which they originate.
- Superior rectal artery - from the Inferior mesenteric artery
- Middle rectal artery - from the internal iliac artery
- Inferior rectal artery - from the internal pudendal artery, which is a branch of the internal iliac artery
3. Locate the following on the model of the torso:
- Splenic flexure
- Haustra
- Taenia libra
- Epiploic appendages
4. The sigmoid colon is located on the posterior wall of the lower abdominal wall, and upper region of
the pelvic cavity. So why is it considered a portion of the hind gut, and not retroperitoneal?
- The sigmoid colon is completely covered by the peritoneum, and thus is part of the hind gut
5. The hind gut is innervated by two sets of nerves. What are they, and what type of innervation do
they supply?
- The lumbar splanchnic nerves provide sympathetic innervation
- The pelvic splanchnic nerves provide parasympathetic innervation
35. What structures, primarily composed of adipose, are associated with the greater and lesser
curvatures of the stomach? Describe their function.
- Greater curvature: greater omentum
- Lesser curvature: lesser omentum
- The greater and lesser omenta function structurally as "shock absorbers" that surround and protect the
abdominal viscera from physical injury. The omenta also function as insulators, protecting the organs
from temperature change.
36. Describe the flow of bile (beginning with its production in the liver and ending in the duodenum).
- Liver(production of Bile) Right and Left Hepatic Duct Common Hepatic Duct Cystic Duct
Gallbladder (storage until needed) Cystic Duct Common Bile Duct (joining with the main pancreatic
duct) Sphincter of Oddi Duodenum
***The following material will not be covered in lecture and not on your test. This is extra information
for future medical anatomy courses***
 Nerves of the Anterolateral Abdominal Wall – Iliohypogastric and
Ilioinguinal nn. (Gilroy pp. 424-427, Moore pp. 193-194)
o The map of dermatomes of the anterolateral abdominal wall is
almost identical to the map of peripheral nerve distribution. This is
because the anterior rami of spinal nerves, T7-T12, which supply
most of the abdominal wall, do not participate in plexus formation.
The exception occurs at the L1 level, where the L1 anterior ramus
bifurcates into two named peripheral nerves.
o The skin and muscles of the anterolateral abdominal wall are
innervated by the following nerves:
 Thoracoabdominal nerves: anterior rami of T7-T11
 Lateral (thoracic) cutaneous branches: T7-T9 or T10
 Subcostal nerves: large anterior ramus of spinal nerve T12
 Iliohypogastric and Ilioinguinal nerves: terminal brances of the
anterior ramus of spinal nerve L1
 During their couse though the anterolateral abdominal wall, the
thoracoabdominal, subcostal, and iliohypogastric nerves
communicate with each other.
Nerves
Origin
Thoracoabdominal
Continuation of
lower (7th -11th )
intercostal
nerves distal to
costal margin
Course
2nd
3rd
Run between
and
layers of
abdominal muscles; branches enter
subcutaneous tissue as lateral cutaneous
branches of T10-T11 (in anterior axillary
line) and anterior cutaneous branches of
T7-T11 (parasternal line)
Distribution
Muscles of anterolateral
abdominal wall and overlying
skin
Anterior division continue across costal
Skin of right and left
Lateral (thoracic)
7th- 9th
margin
in
subcutaneous
tissue
hypochondriac regions
cutaneous branches intercostal
nerves (ant rami
of T7-T9)
Subcostal
Spinal nerve T12 Runs along inferior border of 12th rib; then Muscles of anterolateral
passes onto subumbilical wall between
second and third layers of abdominal
muscles
Iliohypogastric
A superior
terminal branch
of anterior
ramus of L1
Pierces trans. Abd. Muscle to course
between 2nd and 3rd layers of abdominal
muscles; branches pierce external oblique
and aponeuroses of most inferior
abdominal walls
abdominal wall (including
most inf slip of external
oblique) and overlying skin,
superior to iliac crest and
inferior to umbilicus
Skin overlying iliac crest,
upper inguinal, and
hypogastric regions; internal
oblique and transversus
abdominal muscles
Ilioinguinal
A inferior
terminal branch
Passes between second and third layers of
abdominal mauscles; then traverses
inguinal canal
Skin of lower inguinal regions
mons pubis, anterior scrotum
or labium majora, and
of anterior
ramus of L1
adjacent medial thigh;
inferiormost internal oblique
and transversus abdominus