The document provides a detailed summary of the surgical anatomy of the inguinal canal and anterior abdominal wall. It describes the layers of the abdominal wall including muscles, fascia, nerves and blood vessels. It discusses the boundaries and contents of the inguinal canal, including the spermatic cord/round ligament. It also briefly mentions hernias that can occur in the inguinal canal region.

1. SURGICAL ANATOMY OF
INGUINAL CANAL /
ANTERIOR ABDOMINAL WALL
PRESENTER:Dr.S.SIVA SANKAR
Post Graduate Resident
General Surgery

2. Anterior Abdominal wall
● extends from the thoracic cage to the pelvis
bounded superiorly by the cartilages of the
7th to 10th ribs and the xiphoid process of
sternum (level of T9)
● inferiorly by the inguinal ligament and the
superior margins of the anterolateral aspects
of the pelvic girdle (iliac crests ,pubic
crests,and pubic symphsis )

3. L5
L1

4. Transpyloric plane
passes horizontally midway between the xiphoid
process and the umblicus at the level of L1
Transtubercular plane
passes horizontally through the tubercle of the
iliac crest ,about 5cm behind the asis ,at the level of
L5
Two vertical midclavicular line passes through the
midinguinal point.

5. Layers of Abdominal wall
● skin
● superficial fascia
● External oblique muscle
● Internal oblique muscle
● Transversus abdominis muscle
● Transversalis fascia
● preperitoneal adipose tissue
● peritoneum

6. Superficial fascia
● In two layers
● fascia Camper - superficial
fatty layer.
● fascia Scarpa - deep
membranous layer,
superficial fascia

8. Superficial fatty layer (fascia camper)
It is continuous with the superficial fat over the
rest of the body.

9. Deep membranous
layer(fascia scarpa)
● deeper ,dense layer of fibrous connective tissuue
fuses with the fascia lata of the thigh,medial part of
inguinal ligament,and pubic tubercle in the fold of
each groin
● fascia contains
cutaneous nerves ,vessels and superficial
lymphatics

11. Muscles of Anterolateral Abdominal wall
● external oblique
● internal oblique
● transverse abdominis
● rectus abdominis
● pyramidalis

13. External oblique
• Origin: external surfaces and
inferior borders of 5-12 ribs
• Insertion: iliac crest, linea alba, f
• Direction: inferiomedial direction
• Nerve supply: T7 – L1

14. External oblique mucle
● originate from the lower 7 ribs and course in inferomedial
direction
● at the mid clavicular line give rise to flat ,strong
aponeurosis that passes anteriorly to the rectus sheath to
insert medially into the linea alba.
● the most posterior of the fibres run vertically dounward to
insert into the anterioor half of the iliac crest
● the lower portion of the aponeurosis is rolled posteriorly
and superiorly to form a groove extends from the anterior
superior iliac spine to pubic tubercle and is termed the
Inguinal ligament.
● The shelving edge of the inguinal ligament is used in various
repairs of inguinal hernia.

16. Internal oblique
• Origin: thoracolumbar
fascia, iliac crest, lat
2/3 of inguinal ligament
• Insertion: pectan pubis
(conjoint tendon), linea
alba, 10-12 ribs
• Direction:
superomedial
• Nerve supply: T7 – L1

17. Internal oblique muscle
● originates from the iliopsoas fascia ,from the anterior
2/3rd of the iliac crest and lumbo dorsal fascia
● course in a direction opposite of the external oblique
muscle-superomedial
● uppermost fibres insert into the lower five ribs and their
cartilage
● central fibres form an aponeurosis runs medially which
envelops the rectus abdominis muscle as part of rectus
sheath
● some of the lower muscle fascicles accompany the
spermatic cord into the scrotum as the cremasteric
muscle

19. tranverse abdominis muscle
● arises from the lower 6 costal cartilage ,spines
of the lumbar vertebra,iliac crest and ilopsoas
fascia beneath the lateral ⅓ rd of the inuinal
ligament
● course transversely to give rise to flat
aponeurotic sheet that passes posterior to the
rectus abdominis above the semicircular line
(of douglas) and anterior to the muscle below
it.
● inferior most fibres pass infero medially along
with the lower fibres of the internal oblique
and form aponeurotic arch of the transverse
abdominis muscle.

21. transversalis fascia
● covers the deep surface of the transversus abdominis
muscle and ,with its various extensions , forms a complete
fascial envelope across the abdominal cavity
● binds together the muscle and aponeurotic fascicles into a
continuoous layer and reinforces weak areas.
● responsible for the structural integrity of the abdominal
wall
● By definition ,a hernia results from a defect in the
transversalis fascia.

22. Rectus abdominis
• Origin: costal
cartilage 5-7,
xiphoid process
• Insertion:Pubic
crest ,pubic
symphysis
• Direction: vertical
• Nerve supply: T7-
T11
• Tendinous
intersections

23. Rectus sheath

25. linea alba
● the rectus abdominis muscles are held closely in apposition
near the anterior midline by the linea alba .
● consists of a band of dense,crisscrossedfibres of the
aponeurosis of the abdominal muscles extends from the
xiphoid to the pubic symphysis.
● wider above the umblicus than below thus facilitating the
placement of surgical incisions in the midline without
entering the right or left rectus sheath

26. Pyramidalis
• Inconsistent
muscle, within
rectus sheath
• Origin: pubic
symphysis and
pubic crest
• Insertion: linea alba
• Nerve supply: T12

27. PREPERITONEAL ADIPOSE TISSUE
lies between the fascia transversalis and the parietal
peritoneum and contain adipose and areolar tissue.
PARIETAL PERITONEUM
● innermost layer of the abdominal wall..
● consists of a thin layer of dense ,irregular connective
tissue covered on its inner surfae by a single layer of
squamous mesothelium.

28. Blood Supply
LYMPHATICS

29. BLOOD SUPPLY
superior and the inferior epigastric arteries.
The skin near the midline is supplied by branches of the
The skin of the flanks is supplied by branches of
the
● Deep circumflex iliac arteries
● intercostal arteries
● lumbar arteries

30. ● The superior epigastric artery ,one of the terminal
branches of the internal thoracic artery enters the upper
part of the rectus sheath supplies the upper central part
of the anterior abdominal wall and anastomoses with the
inferior epigastric artery.
● The inferior epigastric artery ,branch of the external iliac
artery just above the inguinal ligament supppling the lower
central part of the anterior abdominal wall and
anastomoses with the superior epigastric artery

31. Below the umblicus the skin and superficial fascia are
supplied by three small branches from femoral artery
• Superficial epigastric artery
• Superficial external pudendal artery
• Superficial circumflex iliac artery

32. VENOUS DRAINAGE
SUPERFICIAL VEINS
The superficial veins form a network that
radiates out from the umbilicus.
Above the umblicus , drain into the axillary vein via
the lateral thoracic vein.
Below the umblicus ,drain into the femoral vein via
the superficial epigastric and great saphenous
veins.

33. DEEP VEINS
The deep veins of the abdominal wall, the superior
epigastric, inferior epigastric, and deep
circumflex iliac veins, follow the arteries of the
same name and drain into the internal thoracic
and external iliac veins.

34. lymphatics
above the umblicus,
drain into the axillary lymph nodes.
below the umblicus,
drain into the superficial inguinal nodes
The deep lymphatics
follow the arteries and drain into the internal
thoracic ,external iliac ,posterior mediastinal
and para-aortic nodes
superficial lymphatics

36. • Nerve supply
• Cutaneous nerves
• Lower 5 intercostal nerves
• subcostal nerve
• 1st lumbar nerve
• 1st lumbar nerve is represented by Iliohypogastric and
Ilioinguinal nerves.
• They supply the skin of the anterior abdominal wall,the
muscles and the parietal peritoneum
• Lower six thoracic nerves pierce the posterior Wall of
the rectus sheath and supply the rectus muscle and
pyramidalis
• Dermatome
• Xyphoid process T7
• Pubic symphysis L1

37. Nerve supply

38. skin Incisions

39. INGUINAL CANAL
● it is an intermuscular passage of about 4cm in
length in lower part of abdominal wall
located parallel with and immediately
superior to the medial half of the inguinal
ligament.
● extends between the deep inguinal ring and
superficial inguinal ring.

41. superficial inguinal ring
● it is an ovoid opening of the external oblique
aponeurosis that is positioned superiorly and
slightly lateral to the pubic tubercle.
● bounded by superomedial and inferolateral crus
joined by the crisscross intercrural fibres

42. Deep inguinal ring
● it is an U shaped condensation of the
transversalis fascia.
● lies 1.25 cm above the inguinal ligament
,midway between the symphysis pubis and the
anterior superior iliac spine
● the inferior epiastric vessels lie posteriorly
and medial to the deep inguinal ring

43. Inguinal ligament
● Inguinal ligament is the inferior edge of the
ext. oblique aponeurosis extends from the
anterior superior iliac spine to the pubic
tubercle and turning posteriorly to form the
shelving edge thus forming the inferior wall
of the inguinal canal

45. Boundaries of Inguinal canal
● anteriorly
external oblique aponeurosis.
● superiorly
arched fibres of the internal oblique and
transverse abdominis musculoaponeurosis.
● inferiorly
grooved upper surface of the inguinal
ligament and medial most by lacunar ligament

46. ● posteriorly
transversalis fascia and conjoined tendon
medially
lower parallel fibres of the aponeurosis of
transverse abdominis and internal oblique fuse to
form the conjoint tendon and gets attached to the
pubic crest and pecten pubis thus forms strong
posterior wall for the medial part of the canal .

49. structures passing through the inguinal
canal
● The spermatic cord in males and the round
ligament of the uterus in females ,enters the
inguinal canal through the deep inguinal ring and
passes out through the superficial inguinal ring.
● The ilioinguinal nerve enters the canal through
the interval between the external and internal
oblique muscles runs anterior to the spermatic
cord in the inguinal canal and branches at the
superficial inguinal ring.

50. coverings of spermatic cord
● internal spermatic fascia derived from the
transversalis fascia when it enters the deep
inguinal ring
cremasteric muscle and fascia
arise from the lowermost fibres of the
internal oblique muscle and encompasses the
spermatic cord and attach to the tunica
vaginalis of the testis .
● external spermatic fascia
while passing out from the superficial
inguinal ring spermatic cord receives its outer
coverin from external oblique aponeursis.

52. contents of spermatic cord
● vas deferens
● artery to vas deferens ,
● testicular artery
● pampiniform plexus of veins
● cremasteric vessels
● genital branch of genitofemoral nerve
● remains f processus vaginalis
● lymphatics
● sympathetic plexus around the artery to vas
deferens

53. Cremasteric reflex

54. hernia
● an abnormal protrusion of an organ or tissue
through a defect in its surrounding wall.
•
• Indirect inguinal hernia
• Direct inguinal hernia

55. ● it is the site for
direct hernias.
The triangle has the
following borders:
1) Medial border of rectus
abdominus(medially)
2) Inguinal ligament (inferiorly)
3) Inferior epigastric vessels(laterally)
HESSELBACH’S TRIANGLE