Laboratorio - Anatomia_de_Abdomen_parte II.pdf

Abdomen II.pdf

1. Abdomen II
Loraine V. Valentín Crespo
Ponce Health Sciences
University - MSMS

MMM

2. Peritoneal Cavity

3. Peritoneal Cavity
●It is important to remember that the
peritoneal cavity is the potential space
between the parietal and visceral layers of
the peritoneum.
●During life, the surfaces of the organs
(covered by visceral peritoneum) are in
contact with the parietal peritoneum of the
body wall, reducing the peritoneal cavity only
to a potential space containing some serous
fluid.
●The peritoneal cavity consists of two
portions:
-Greater Sac
-Lesser Sac (also known Omental
Bursa)

4. Greater and Lesser Omentum

5. Greater Omentum
●The greater omentum is a prominent,
four layered peritoneal fold that hangs
from the stomach and the proximal part of
the duodenum.
●After descending, it folds back and
attaches to the anterior surface of the
transverse colon and its mesentery.
●The greater omentum is divided into three
portions:
-Gastrocolic Ligament
-Gastrophrenic Ligament
-Gastrosplenic Ligament

6. Ligaments of the Greater Omentum
●The gastrocolic ligament is that part of
the greater omentum attached to the
greater curvature of the stomach and
covers anteriorly the transverse colon and
extends inferiorly to cover portions of the
small intestine.
●The gastrophrenic ligament connects
the superior part of the greater curvature
of the stomach to the inferior aspect of the
diaphragm.
●The gastrosplenic ligament passes from
the greater curvature of the stomach to the
spleen.

7. Lesser Omentum
●The lesser omentum is a much smaller,
double layered peritoneal fold that
connects the lesser curvature of the
stomach and the proximal part of the
duodenum to the liver.
●It also connects the stomach to the triad of
structures that run between the duodenum
and liver in the free edge of the lesser
omentum.
●The greater omentum is divided into two
portions:
-Hepatogastric Ligament
-Hepatoduodenal Ligament

8. Stomach and Omenta

9. Curvatures of the Stomach
●In the stomach we can identify two
curvatures:
-Greater Curvature
-Lesser Curvature

10. External Features of the Stomach
●The stomach is divided into four parts:
-Cardia
-Body
-Fundus
-Pyloric Region
➔Pyloric Antrum
➔Pyloric Canal
●In the stomach we also have the angular
notch (incisura angularis) that
represents the junction of the body with
the pyloric region of the stomach in the
lesser curvature.

11. Internal Features of the Stomach
●In the interior of the stomach we can
observe gastric folds called rugae.
●The rugae allow the stomach to stretch in
order to accommodate large meals and
help to grip and move food during
digestion.

12. Small Intestine

13. Small Intestine
●The small intestine is composed of three
portions:
-Duodenum
-Jejunum
-Ileum

14. Small Intestine: Duodenum
●The duodenum is C-shaped and molded
around the head of the pancreas.
●The duodenum is described as having four
parts:
-Superior
-Descending
-Horizontal
-Ascending
●The first part of the duodenum has a
mesentery and is very mobile.
●It is important to note that the rest of the
duodenum is immobile because it is
retroperitoneal.

15. Small Intestine: Internal Features of the Duodenum
●Inside the duodenum, on the inner surface
of the medial wall of the second part, there
are two elevations of the mucosa known
as papillae.
●The first elevation is called the minor
duodenal papilla.
●The second elevation is called the major
duodenal papilla.

16. Small Intestine: Hepatopancreatic Ampulla of the Duodenum
●It is important to know that the common
bile duct joins the main pancreatic duct
to form the hepatopancreatic ampulla (of
Vater).
●This ampulla has a sphincter known as the
hepatopancreatic sphincter (of Oddi).
●After the union, the hepatopancreatic
ampulla opens on the major duodenal
papilla.
●The opening of the major duodenal papilla
is the narrowest part of the biliary
passages and thus a common site for
impaction of a gallstone.

17. Small Intestine: Accessory Pancreatic Duct in the Duodenum
●It is important to remember that the
accessory pancreatic duct (if present)
opens on the minor duodenal papilla.
●The accessory pancreatic duct drains the
uncinate process and the inferior part of
the head of the pancreas.
●The accessory pancreatic duct usually
joins the main pancreatic duct, but in some
people, it is a separate duct (in which
case, open into the minor duodenal
papilla).

18. Small Intestine: Duodenojejunal Flexure
●The duodenojejunal flexure
(duodenojejunal junction) is the part of
the small intestine where the duodenum
ends and the jejunum starts.
●This junction occurs approximately at the
level of the L2 vertebra.

19. Small Intestine: Suspensory Ligament of the Duodenum
●The ascending part of the duodenum is
suspended by the suspensory ligament
(muscle) of the duodenum also known
as the ligament of Treitz.
●This ligament is a band of retroperitoneal
fibrous and muscular tissue that arises
from the right crus of the diaphragm,
descends and crosses to the opposite side
and anchors the intestine at the duodenal
junction.

20. Small Intestine: Jejunum and Ileum
●The second part of the small intestine, the
jejunum, begins at the duodenojejunal
junction.
●The third part of the small intestine, the
ileum, ends at the ileocecal junction
which is the union of the terminal ileum
and the cecum.
●The mesentery is a fan-shaped fold of the
peritoneum that attaches the jejunum and
ileum to the posterior abdominal wall.
●The root of the mesentery extends from
the duodenojejunal junction on the left side
of vertebra L2 to the ileocolic junction and
the right sacroiliac joint.

21. Small Intestine: Mesentery

22. Large Intestine

23. Large Intestine
●As mentioned before, the large intestine
frames the small intestine on three sides:
-The cecum and the ascending
colon frame the small intestine on
the right side.
-The transverse colon frames the
small intestine on the superior part.
-The descending colon and the
sigmoid colon frame the small
intestine on the left side.

24. Large Intestine: Ileocecal Junction
●The ileocecal junction is the union of the
ileum (small intestine) with the cecum
(large intestine).
●The orifice that allows material to cross
from the ileum to the cecum is called
ileocecal orifice which is bounded by the
ileocecal valve.

25. Large Intestine: Vermiform Appendix
●The appendix, also called vermiform
appendix, is a blind intestinal diverticulum
that contains masses of lymphoid tissue.
●The appendix has a short triangular
mesentery, the mesoappendix, that
attaches to the cecum and the proximal
part of the appendix.
●The mesoappendix contains the
appendicular artery which supplies the
appendix.

26. Large Intestine: Ascending Colon
●The ascending colon is the second part
of the large intestine.
●The ascending colon passes superiorly on
the right sight of the abdominal cavity from
the cecum to the right lobe of the liver,
where it turns to the left at the right colic
flexure, also called hepatic flexure.

27. Large Intestine: Transverse Colon
●The transverse colon is the third, longest
and most mobile part of the large intestine.
●The transverse colon crosses the abdomen
from the right colic flexure to the left colic
flexure (splenic flexure), where it turns
inferiorly to become the descending colon.
●It is important to note that the left colic flexure
is attached to the diaphragm by the
phrenicocolic ligament.
●Another important concept is that between
the two flexures, the transverse colon is
freely moveable.
●Its mesentery is called the transverse
mesocolon and it adheres to the inferior
border of the pancreas.

28. Large Intestine: Descending Colon
●The descending colon descends from
the sharply curved left colic flexure to the
pelvis.
●The posterior surface of the descending
colon is attached to the posterior
abdominal wall, therefore, it is
retroperitoneal.
●Retroperitoneal: Organs are
retroperitoneal if they have peritoneum on
their anterior side only. Structures that are
not suspended by mesentery in the
abdominal cavity and that lie between the
parietal peritoneum and abdominal wall
are classified as retroperitoneal.

29. Large Intestine: Sigmoid Colon
●The sigmoid colon, characterized by its
S-shaped loop of variable length, links the
descending colon and the rectum.
●The sigmoid colon usually has a long
mesentery, the sigmoid mesocolon, and
therefore has considerable freedom of
movement, especially its middle part.
●The rectosigmoid junction is the part of
sigmoid colon where it connects with the
rectum and it at the level of the vertebra
S3.

30. Large Intestine: General Features
●The large intestine has three features that
are purely characteristic of this organ:
-Taeniae Coli
The taeniae coli are three narrow
longitudinal bands of smooth muscle
that begin at the base of the
appendix and traverse the length of
the large intestine to terminate in the
wall of the rectum.
-Haustras
The haustras are sacculations of
the wall of the colon between the
taeniae.
-Appendices Epiploicae
The appendices epiploicae are small
bags of fat that hang from the colon.

32. Anatomical Note: Sigmoid Colon vs Rectum
●The rectum differs from the sigmoid
colon in having no sacculations,
appendices epiploicae or mesentery.
●The taeniae blend 5 cm above the
rectosigmoid junction, forming two wide
muscular bands, which descend anteriorly
and posteriorly in the rectal wall.
●These the fuse to form an encircling layer
of longitudinal muscle, which invests the
entire length of the rectum.

33. Liver

34. Surfaces of the Liver
●The liver has a convex diaphragmatic
surface and a relatively flat visceral
surface.

35. Structures of the Visceral Surface of the Liver
●In the visceral surface of the liver we can
find the following structures:
-Inferior Vena Cava
-Gallbladder
-Ligamentum Venosum
-Ligamentum Teres
-Porta Hepatis

36. Liver: Porta Hepatis
●The porta hepatis is a transverse fissure
where the vessels, the hepatic nerve
plexus and the hepatic ducts that supply
and drain the liver enter and leave it.
●In the porta hepatis we can identify the
following structures:
-Portal Veins
-Hepatic Arteries
-Hepatic Ducts

37. Study Questions
1.The right and left hepatic ducts join to form the common hepatic duct.
2.The right and left hepatic arteries are branches of the hepatic artery proper.

38. Liver: Lobes
●The liver is composed of four lobes:
-Right Lobe
-Left Lobe
-Quadrate Lobe
-Caudate Lobe

39. Liver: Relationship with Lesser Omentum
●The lesser omentum stretches from the
lesser curvature stomach and from the
initial portion of the duodenum to the
visceral surface of the liver.
●At the right margin of the lesser omentum
we can identify the hepatoduodenal
ligament.
●It is important to note that between the two
peritoneal layers of the hepatoduodenal
ligament we can identify the structures that
comprise the portal triad:
-Portal Vein
-Hepatic Artery Proper
-Common Bile Duct

40. Liver: Relationship with Lesser Omentum
●The epiploic foramen (of Winslow) is an
orifice located at the hepatoduodenal
ligament that gives access to the lesser
sac (omental bursa).
●If we put a finger through this foramen and
direct our fingers inferiorly we have access
to the inferior recess of the lesser sac.
●If we direct our fingers superiorly we have
access to the superior recess of the lesser
sac.

41. Liver: Peritoneal Attachments
●The falciform ligament attaches the liver
to the front body wall, and separates the
liver into the left medial lobe and right
lateral lobe.
●The falciform ligament also divides the
subphrenic recess into right and left
recesses.
●The diaphragmatic surface of the liver is
covered with visceral peritoneum, except
in the bare area of the liver.
●The bare area of the liver is demarcated
by the reflection of peritoneum from the
diaphragm to it as the anterior and
posterior layers of the coronary ligament.

42. Liver: Peritoneal Attachments
●The anterior and posterior portions of the
coronary ligament fuse together and form
the left and right triangular ligaments.
●The inferior part of the coronary ligament
is reflected onto the diaphragm and the
right kidney, therefore it is alternatively
called the hepatorenal ligament.
●Inferior to the hepatorenal ligament is a
potential peritoneal space called the
hepatorenal recess (of Morrison).

43. Liver: Peritoneal Attachments

44. Biliary Ducts and the Gallbladder

45. Biliary Ducts
●The right and left hepatic ducts drain the
right and left parts of the liver into the
common hepatic duct.
●The common hepatic duct joins with the
cystic duct to form the bile duct which is
the structure responsible of conveying the
bile to the duodenum.
●An important structure is the hepatocystic
triangle (of Callot) which is composed of
the cystic duct, the common hepatic duct
and the liver.
●It is also important to note that the cystic
artery is located is the hepatocystic
triangle (of Callot).
2

46. Gallbladder
●The gallbladder stores bile produced by
the liver.
●The gallbladder connects to the bile duct
via the cystic duct.
●The gallbladder has the following three
regions:
-Fundus
-Body
-Neck
●The gallbladder also has four contact
relations: the liver, the duodenum, the
transverse colon and the anterior
abdominal wall.

47. Clinical Correlation: Cholecystoenteric Fistula
●An inflamed gallbladder can become adherent
to the intestinal tract, notably the duodenum or
the transverse colon with which the gallbladder
is close to.
●Subsequently, a fistula between the gallbladder
and the gastrointestinal tract (cholecystoenteric
fistula) may develop through which bile or
gallstones can enter the gastrointestinal tract.
●For example, a large single gallstone could
perforate into the duodenum and pass through
the jejunum and the ileum all the way to the
ileocecal valve.
●If the gallstone cannot pass through this narrow
valve, bowel obstruction will result with
disastrous consequences.

48. Clinical Correlation: Cholecystoenteric Fistula

49. Spleen

50. Spleen
●The spleen lies posterior to the stomach and is
normally located in the upper left quadrant of
the abdomen just inferior to the diaphragm and
opposite to the ninth, tenth and eleventh ribs.
●In the spleen we can find the following features:
Hilus, Visceral Surface and Diaphragmatic
Surface.
●The spleen also has the following peritoneal
attachments:
-Splenorenal Ligament
Attaches the spleen to the left kidney.
-Gastrosplenic Ligament
Attaches the spleen to the greater
curvature of the stomach.

51. Pancreas

52. Pancreas
●In the pancreas we can identify the
following structures:
-Head
-Uncinate Process (Lingula)
-Neck
-Body
-Tail
●The inferior vena cava and the common
bile duct are found posterior to the head of
the pancreas.
●It is also important to note that the
uncinate process lies posterior to the
superior mesenteric vessels.

53. Pancrea: Vessels and Ducts
●The anterior and posterior
pancreaticoduodenal arteries arise from
the superior pancreaticoduodenal
artery.
●The inferior pancreaticoduodenal artery
arises from the superior mesenteric
artery.
●In the pancreas we can also locate the
main pancreatic duct and the accessory
pancreatic duct.

54. Pancrea: Vessels and Ducts
●As mentioned before, the main pancreatic duct
begins at the tail of the pancreas and runs through
the substance of the gland to the head, where it
runs inferiorly and joins the common bile duct.
●The common bile duct and the main pancreatic
duct unite to form a dilated hepatopancreatic
ampulla (of Vater) which opens into the second
(descending) part of the duodenum at the summit
of the major duodenal papilla.
●The hepatopancreatic sphincter of Oddi is
located around the hepatopancreatic ampulla.
●The accessory pancreatic duct drains the
uncinate process and the inferior part of the head
of the pancreas and opens into the duodenum at
the minor duodenal papilla.

55. Peritoneal Gutters

56. Peritoneal Gutters
●Peritoneal Gutters, also known as
peritoneal recesses, are spaces formed by
the peritoneum draping over viscera.
●The term refers mainly to four spaces:
-Right Lateral (Paracolic) Gutter
-Left Lateral (Paracolic) Gutter
-Gutter to the Right of the
Mesentery
-Gutter to the Left of the Mesentery

57. Blood Vessels of the Abdomen

58. General Abdominal Blood Vessels
●In the posterior abdominal wall we can find
the following blood vessels:
-Abdominal Aorta
-Right and Left Common Iliac
Arteries
●It is important to note that the abdominal
aorta terminates at the level of the
vertebra T4 where it bifurcates into the
right and left common iliac arteries.

59. General Abdominal Blood Vessels
●The celiac trunk arises from the
abdominal aorta immediately inferior to the
diaphragm.
●The celiac trunk has three main branches:
-Common Hepatic Artery
-Left Gastric Artery
-Splenic Artery

60. General Abdominal Blood Vessels
●The common hepatic artery has the
following branches:
-Hepatic Artery Proper
-Gastroduodenal Artery

61. General Abdominal Blood Vessels
●The hepatic artery proper has the
following branches:
-Right Gastric Artery
-Left Hepatic Artery
-Right Hepatic Artery
Right&left
gastric
arters
->
anastomers

62. General Abdominal Blood Vessels
●The gastroduodenal artery has the
following branches:
-Supraduodenal Artery
-Superior Pancreaticoduodenal
Artery
-Right Gastroepiploic Artery

63. General Abdominal Blood Vessels
●The splenic artery has the following blood
vessels:
-Short Gastric Arteries
-Left Gastroepiploic Artery (Left
Gastro-Omental Artery)

64. General Abdominal Blood Vessels
●The superior mesenteric artery arises from
the abdominal aorta about 1 cm caudal to the
celiac trunk.
●It is important to note that the superior
mesenteric artery lies posterior to the neck of
the pancreas and passes anterior to the third
part of the duodenum and the left renal vein.
●The superior mesenteric artery has the
following branches:
-Inferior Pancreaticoduodenal
-Intestinal Branches and Vasa Recta
-Ileocolic Artery
-Appendicular Artery
-Right Colic Artery
-Middle Colic Artery

65. General Abdominal Blood Vessels

66. General Abdominal Blood Vessels
●The inferior mesenteric artery arises from
the abdominal aorta about 3 cm superior to
the aortic bifurcation.
●The inferior mesenteric aorta has the
following branches:
-Left Colic Artery
-Sigmoid Arteries
-Superior Rectal Arteries
●In the abdomen we can also identify the
marginal artery (of Drummond) that runs
along the inner border of the large intestine.
●It is important to note that the marginal
artery is formed by an anastomosis that
involves branches of both the superior and
inferior mesenteric arteries.

67. General Abdominal Blood Vessels

68. General Abdominal Blood Vessels
●The following structures are venous
tributaries of the portal vein:
-Superior Mesenteric Vein
-Splenic Vein
-Inferior Mesenteric Vein
●The superior mesenteric vein and the
splenic vein join to form the portal vein
posterior to the neck of the pancreas.
●The inferior mesenteric vein may join the
superior mesenteric vein, the splenic vein
or the junction of the superior mesenteric
and splenic veins.
●In this diagram, the inferior mesenteric
vein joins the splenic vein.

69. General Abdominal Blood Vessels
●The following structures are tributaries of
the splenic vein:
-Short Gastric Vein
-Left Gastroepiploic Vein
-Pancreatic Veins

70. General Abdominal Blood Vessels
●The following structures are tributaries of
the superior mesenteric vein:
-Right Gastroepiploic Vein
-Inferior Pancreaticoduodenal Vein
-Jejunal and Ileal Veins
-Ileocolic Vein
-Right Colic Vein
-Middle Colic Vein

71. General Abdominal Blood Vessels

72. General Abdominal Blood Vessels
●The following structures are tributaries of
the inferior mesenteric vein:
-Left Colic Vein
-Sigmoidal Vein
-Superior Rectal Vein
●It is important to remember that the
superior rectal vein communicates with the
middle and inferior rectal veins to form a
rectal plexus.

73. General Abdominal Blood Vessels
●The following veins also drain into the portal vein:
-Right and Left Gastric Veins
-Superior Pancreaticoduodenal Vein
-Paraumbilical Veins
●The left gastric vein also drains the lower one-third of the esophagus.
●These esophageal branches of the left gastric vein connect with esophageal branches of the
azygos vein system.
●The paraumbilical veins accompany the ligamentum teres in the free, lower border of the
falciform ligament.
●The paraumbilical veins connect with the periumbilical plexus of veins.
●The paraumbilical veins are subcutaneous veins that radiate out from the umbilicus in the
anterior abdominal wall.
●They are branches of the superior and inferior epigastric veins.

74. General Abdominal Blood Vessels

75. Clinical Correlation: Portal Hypertension from Cirrhosis
●Increased pressure in the portal system
(portal hypertension), which most often
results from cirrhosis, blood from the lower
one-third of the esophagus flows into the
azygos vein instead of flowing into the
portal vein via the left gastric.
●As a result, the submucosal venous plexus
of the lower one-third of the esophagus
becomes dilated and congested and is
prone to bleeding (esophageal varices).
●Also, enlargement (varices) of veins in the
rectum and around the umbilicus can occur,
causing hemorrhoids and caput medusa.

76. Clinical Correlation: Superior Mesenteric Syndrome (Nutcracker
Syndrome)
●The left renal vein and the third part of
the duodenum pass between the aorta
posteriorly and the superior mesenteric
vessels anteriorly.
●These structures can become compressed
like nuts in a nutcracker.
-
nas-sibutar

77. Kidneys and Suprarenal Glands

78. Kidneys
●The kidneys are bean-shaped
retroperitoneal organs lying on the posterior
abdominal wall, one on each side of the
vertebral column.
●It is important to note that the right kidney is
lower than the left because of the position
of the liver.
●The renal hilus is the entrance to a space
within the kidney, the renal sinus.
●The renal hilus is located at the medial
border of the kidney and through it the
renal veins, arteries and ureters traverse.
●At the hilus, the renal vein is anterior, the
ureter is posterior and the renal artery is
between these two other structures.

79. Kidneys: Renal Fascia
●The external anatomy of the kidneys
comprises the structure known as renal
fascia (false capsule).
●The renal fascia is thicker in the lateral
and posterior surfaces of the kidneys.
●The renal fascia divides the fat associated
with the kidneys into two regions:
-Perirenal Fat
Fat inside the renal fascia (fatty
capsule).
-Pararenal Fat
Fat outside the renal fascia.

80. Kidneys: Renal Veins
●The renal veins drain into the inferior
vena cava (IVC).
●It is important to note that the left renal
vein is much longer than its right
counterpart and that it is compressed
between the abdominal aorta posteriorly
and the superior mesenteric artery
anteriorly.
●The venous tributaries of the left renal vein
are:
-Left Testicular Vein
-Left Ovarian Vein
●The right testicular vein drains directly
into the inferior vena cava as well as the
right ovarian vein.

81. Kidneys: Renal Arteries
●The renal arteries lie posterior to the renal
veins and they usually divide into two
branches before entering the kidneys.
●It is also very common to find accessory
renal arteries.
●It is important to note that in the male the
right and left testicular arteries originate
directly from the aorta, inferior to the origin
of the renal arteries.
●In the female, the corresponding ovarian
vessels cross the external iliac vessels to
enter the pelvis.
●As a side note, the right renal artery is
longer than the left renal artery.

82. Anatomy of the Kidney
●The renal pelvis is located at the most
posterior part of the renal hilus.
●The ureter is an inferior continuation of
the renal pelvis.
●Its is important to note that the ureter runs
posterior to the testicular (ovarian)
vessels.
●In the kidney we can also identify the
following structures:
-Renal Cortex
-Renal Medulla
-Renal Pyramids
-Renal Papillae
-Calyces Minores
-Calyces Majores

83. Anatomy of the Kidney
●The renal cortex extends between
pyramids as renal columns.
●The renal medulla is the inner zone of the
kidney where renal pyramids are
separated by renal columns.
●The renal pyramids form the medulla of
the kidneys.
●The renal papillae project into small cups,
the calyces minores.
●The calyces minores unite to form two or
three calyces majores.
●The calyces majores unite to form the
renal pelvis.

84. Suprarenal Glands
●The adrenal glands (also known as
suprarenal glands) are endocrine glands
that produce a variety of hormones
including adrenaline and the steroids
aldosterone and cortisol.
●The suprarenal glands are separated from
the superior pole of the kidneys by a thin
layer of fat.
●The right suprarenal gland is roughly
triangular in shape and lies posterior to the
inferior vena cava.
●The left suprarenal gland is semilunar in
shape and is closely adjacent to the
superior and medial borders of the left
kidney.

85. Arterial Supply of Suprarenal Glands
●Numerous arteries supply the suprarenal
glands and they come from different
sources.
●The most important arteries that supply
the adrenal glands are the following:
-Superior Suprarenal Artery
Arises from the inferior phrenic
arteries.
-Middle Suprarenal Artery
Arises from the abdominal aorta.
-Inferior Suprarenal Artery
Arises from the renal arteries.

86. Venous Drainage of Suprarenal Glands
●The venous drainage of the adrenal
(suprarenal) glands is typically comprised
of a single vein draining each adrenal
gland.
●The left suprarenal vein drains the left
suprarenal gland and the right suprarenal
vein drains the right suprarenal gland.

87. Abdominal Nerves

88. Abdominal Nerves
●In the abdominal region we can find
numerous nerves and among them are the
following:
-Subcostal Nerve
Name given to the intercostal nerve
twelve.
-Iliohypogastric Nerve
Courses between the transversus
and internal oblique muscle supplying
both and then perforates the
aponeurosis of the external oblique to
become sensory above the pubis.
-Ilioinguinal Nerve
Arises from a common trunk with the
above nerve; sometimes it is absent.

90. Abdominal Nerves
-Lateral Femoral Cutaneous Nerve
Passes beneath the inguinal ligament.
-Femoral Nerve
Lies in the angle of the psoas major and
iliacus muscle.
-Genitofemoral Nerve
Pierces the anterior surface of the psoas
major muscle and descends on it. It is also
above the inguinal ligament and divides into
genital and femoral branches. The
genitofemoral nerve contains the sensory
(femoral branch) and motor fibers
(genital branch) of the male cremasteric
reflex. The genital branch enters the deep
inguinal ring and runs within the inguinal
canal.

92. Abdominal Nerves
-Obturator Nerve
Appears at the medial border of the
psoas major muscle.
-Accessory Obturator Nerve
Absent in about 90% of the population,
if it is present it descends along the medial
border of the psoas major muscle.
-Lumbosacral Trunk
It descends on the ala of the sacrum to
enter the pelvis. It consists of ventral
primary rami of part of L4 and all of the L5.
The lumbosacral trunk contributes to the
formation of the sacral plexus.

93. Muscles of the Posterior Abdominal Wall

94. Muscles of Posterior Abdominal Wall
●In the posterior abdominal wall we can find
the following muscles:
-Psoas Major
-Psoas Minor
-Iliacus
-Quadratus Lumborum
-Transversus Abdominis

95. Abdominal Aorta

96. Abdominal Aorta
●The abdominal aorta is the continuation of
the thoracic aorta.
●It begins at the vertebral level T12 and ends
by bifurcating at vertebral level L4 to form
the right and left common iliac arteries.
●The following arteries arise from the
abdominal aorta:
-Inferior Phrenic Arteries
-Celiac Trunk
-Superior Mesenteric Artery
-Inferior Mesenteric Artery
-Renal Artery
-Testicular and Ovarian Arteries
-Lumbar Arteries
-Common Iliac Arteries

97. Inferior Vena Cava

98. Inferior Vena Cava
●The inferior vena cava is located to the
right of the abdominal aorta.
●It originates at the level of the L5 where the
right and left common iliac veins join.
●It ends at vertebral level T8 by passing
through the central tendon of the diaphragm
to empty into the right atrium.
●The inferior vena cava receives venous
drainage from the following veins:
-Renal Veins
-Suprarenal Vein
-Testicular Ovarian Vein
-Lumbar Veins
-Inferior Phrenic Veins
-Hepatic Veins

99. Inferior Vena Cava
●The inferior vena cava has no tributaries from the gastrointestinal tract
because blood from the gastrointestinal tract is collected by the portal vein
and drained into the liver.
●From the liver, the hepatic veins then empty the blood into the inferior vena
cava.

100. Diaphragm

101. Diaphragm
●In the diaphragm we can identify four
portions:
-Sternal Part
Attaches to the xiphoid process.
-Costal Part
Attaches to the lower six ribs and
costal cartilages.
-Lumbar Part
Attaches to the superior three
lumbar vertebral bodies.
-Central Part
Is the aponeurotic insertion of the
muscle.

102. Diaphragm
●The lumbar portion of the diaphragm is
formed by the following two crura:
-Left Crus
-Right Crus
●The right crus wraps around the
esophagus to form the esophageal hiatus.
●A muscle slip from the right crus running
inferomedially is the remaining portion of
the suspensory muscle of the duodenum
(ligament of Treitz) that supports the
duodenojejunal flexure.

103. Diaphragm
●The arcuate ligaments (lumbocostal
arches) are thickening of transversalis
fascia that serve as attachments for some
fibers of the diaphragms.
●The following ligaments comprise the
arcuate ligaments:
-Medial Arcuate Ligament
Across the psoas major muscle.
-Lateral Arcuate Ligament
Across the quadratus lumborum.
-Median Arcuate Ligament
Uniting the crura of the
diaphragm and passing over the
anterior surface of the aorta.

104. Diaphragm
●The diaphragm has the following
openings:
-Caval Foramen
-Esophageal Hiatus
-Aortic Hiatus
●It is important to note that the higher the
vertebral level, the more ventral is the
opening or hiatus in the diaphragm.

105. Spermatic Cord, Scrotum and Testis

106. Spermatic Cord
●The spermatic cord contains the
following structures:
-Vas Deferens
-Testicular Artery
-Pampiniform Plexus of Veins
-Cremasteric Artery
-Artery to the Vas Deferens
-Genital Branch of the
Genitofemoral Nerve
-Autonomic Fibers
-Lymphatic Vessels

109. Spermatic Cord
●The covering of the spermatic cord are:
-External Spermatic Fascia
Derived from the aponeurosis of
the external oblique muscle.
-Cremasteric Muscle and Fascia
Derived from the internal oblique
muscle.
-Internal Spermatic Fascia
Derived from transversalis fascia.

110. Spermatic Cord
●Under normal circumstances, the
spermatic cord contains only a delicate
thread-like remnant of the peritoneum
because the processus vaginalis fuses
after testicular descent.
●What is the processus vaginalis?
●What is the tunica vaginalis?

111. Scrotum

112. Scrotum
●The scrotum is an outpouching of the
anterior abdominal wall, and most layers
of the abdominal wall and spermatic cord
are represented in its structure.
●The superficial fascia of the scrotum is
called the dartos fascia.
●Dartos fascia is fat-free and contains
smooth muscle fibers called dartos
muscle, which normally lends a creased or
rugous character to the skin.
●Dartos fascia is continuous with Scarpa’s
fascia over the anterior abdominal wall
and with Colle’s fascia of the perineum.

113. Scrotum
●Deep to the dartos fascia the scrotal wall
contains three fascial layers:
-External Spermatic Fascia
-Cremasteric Fascia
-Internal Spermatic Fascia
●This fascia layers are similar to the
coverings of the spermatic cord.

115. Resources
Moore, K. L., Agur, A. M., & Dalley, A. F. (2019). Clinically Oriented Anatomy. Philadelphia, PA: Wolters
Kluwer Health.
Netter, F. H., Machado, C. A., & Hansen, J. T. (2018). Atlas of Human Anatomy. Philadelphia, PA: Elsevier.