Anterior abdominal wall and the inguinal region
Dr . Selda Önderoğlu
ABDOMEN
• The region between: Diaphragm and pelvis.
• Boundaries:
Roof: Diaphragm
Posterior: Lumbar vertebrae+ Mm. Of the posterior abd.
wall
Infrerior: No boundary, continuous with the pelvic cavity,
Superior Pelvic aperture
Anterior and lateral: Anterior Abdominal Wall , Muscles
Bony
structures
of
the
abdomen
Posterior
abdominal wall
Topography of the Abdomen
(PLANES)
TRANSVERSE PLANES
• Transpyloric plane : tip of 9th costal cartilages ; pylorus
of stomach , L1 vertebra level.
• Subcostal plane: tip of 10th costal cartilages , L3 vertebra.
• Transtubercular plane: tubercles if iliac crests ; L5
vertebra level.
• Interspinous plane: anterior superior iliac spines ;
promontory of sacrum
VERTICAL PLANES
• Mid-clavicular plane: midpoint of clavicle- mid-point of
inguinal ligament.
• Semilunar line: lateral border of rectus abdominis muscle.
Planes
of
abdomen
Regions of the Abdomen
• 9 regions:
umbilical (around the umbilicus)
epigastric;hypogastric
L hypochondriac ; R hypochondriac
L inguinal ; R inguinal
L lumbar ; R lumbar region.
Regions
of
abdomen
Cutaneous nn. Of
the anterior
abdominal wall
Skin innervation:
lower 5 intercostal
nerves+ subcostal
nerve+ L1 spinal nerve
(ilioinguinal+iliohypogastric
nn.).
Umbilical region skin
inn.: T10.
Anterior Abdominal Wall
• Skin
• Superficial fascia ( two layers)
superficial fatty layer(CAMPER’S fascia)
deep membranous layer(SCARPA’S fascia)
• No deep fascia
• External oblique muscle
• Internal oblique muscle
• Transversus abdominis muscle
• Transversalis fascia
• Lateral to midline(linea alba)- rectus abdominis
muscle.
• Extraperitoneal tissue layer- peritoneum.
Superficial fascia
two layers
1-superficial fatty layer
(CAMPER’S fascia)
2-deep membranous layer
(SCARPA’S fascia) –
Muscles of the ant.abd.wall
External oblique muscle (most superf.m)
Internal oblique muscle
Transversus abdominis muscle
Those 3 mm are laterally located
On both sides of the midline(linea alba)
Rectus abdominis muscle
inferiorly:Pyramidalis muscle
External Oblique Muscle
(M. Obliquus externus abdominis)
•
•
•
•
Most superficial muscle.
O: 5-12 ribs
I: Linea alba+ inguinal ligament
Parts of inguinal lig.: reflected part +lacunar
ligament+ pectineal Lig.
• Inn: lower 5 intercostal nn.+ subcostal n.+ L1.
• Superficial inguinal ring: opening in the
aponeurosis of external Oblique Muscle.
has: Lateral crus-medial crus- intercrural
fibres.
inguinal ligament
from anterior sup.
iliac spine- to pubic
symphsis
lacunar ligament
pectineal ligament
Superficial
inguinal
Ring
-Lat.crus
-Medial crus
-intercrural fibers
Internal Oblique Muscle
(Musculus Obliquus internus abdominis)
• -middle layer muscle
-fibers are 90 degrees to external oblique
m.fibers
• O:thoracolumbar fascia+iliac crest+inguinal
lig.
• I: linea alba+conjoint tendon ( common
tendon with the transversus abdominis
muscle)+ Pubic crest+pecten pubis.
• Inn.:lower5 intercostal nn+subcostal n.+L1.
(same with external oblique).
TRANSVERSUS ABDOMINIS MUSCLE
• located Innermost
• O: inf. 6 Costal cartilages+Thoracolumbar
fascia+inguinal ligament
• I: conjoint tendon+linea alba.
• Innerv.:lower5 intercostal nn.+ subcostal
n.+ L1. (same with external oblique)
• TRANSVERSALIS FASCIA
• Located post to transv. Abd. m.
deep inguinal ring.
• CONJOINT TENDON ( FALX
INGUINALIS): common tendon of
internal oblique+ transversus abdominis
mm.
Functions of anterior Abdominal
muscles
• support+protection+movements of trunk (
external oblique- turns the trunk to the other
side); internal oblique( turns the trunk to the
same side).
• During coughing,sneezing, vomiting,
parturition ( during birth of a child) all of
these muscles contract( increase intraabdominal pressure.)
Rectus Abdominis Muscle
•
•
•
•
Located on both sides of midline(linea alba)
O: Xiphoid process
I: symphysis pubis
Inn: lower 5 intercostal nn.+ subcostal nn!!
( different from the previous 3 Mm.)
• F: flexes the trunk.
• Has tendinous intersections:3-4 in number
• enveloped by a sheath:RECTUS SHEATH.
• Lat. Border: semilunar line
Rectus
abdominis
muscle
Rectus
sheath
RECTUS SHEATH
• 4-5cm below UMBILICUS -ARCUATE LINE (SEMICIRCULAR
LINE) :
ABOVE this line:
Anterior layer : external oblique apon. + anterior lamina of internal
oblique’s aponeurosis.)
Posterior layer: Posterior lamina of internal oblique apon.+
transversus abdominis apon.
BELOW this line:
Anterior layer : external oblique apon.+internal oblique
apon.+transversus abdominis aponeurosis.
Posterior layer: Only Transversalis fascia.
• Structures within the rectus sheath: rectus abdominis
muscle+ superior epigastric artery+ inferior epigastric artery+ lower
5 intercostal nn.+ subcostal n.
Rectus sheath
Arteries of anterior
Abdominal wall
-musculophrenic
-Sup epigastric
-İnferior epigastric
-Deep circumflex iliac
-Superficial circ.iliac
INGUINAL CANAL
• Surgically an important canal because it is the site of
inguinal hernias
• obliquely located;tubelike
• 3-4cm. in length.
• Has two openings :
• Superficial inguinal ring
external oblique apon.
-medial
• Deep ingunal ring:
transversalis fascia
- Lateral
inguinal canal
•
•
•
•
•
•
superficial inguinal ring
Anterior wall
Post. Wall
Superior wall
inferior wall
deep inguinal ring
4-6 cm
INGUINAL CANAL
• WALLS:
• anterior wall: skin+ superficial fascia+external
oblique (medially)+ internal oblique ( laterally).
• Posterior wall: Reflected ingunal lig.+ conjoint
tendon+ transversalis fascia.
• Inferior wall: inguinal lig.+ lacunar lig.
• Superior wall: inferior margins of internal
oblique+ transversus abdominis mm.
Structures passing through Ingunal
Canal
•
•
•
•
Spermatic cord in male
Round ligament of uterus in female.
Ilioinguinal n..
Genital branch of genitofemoral n.
Superficial inguinal ring
INGUINAL HERNIA
• Indirect Inguinal hernia: piece of organ passes
through deep ing. ring- courses in inguinal canal –
passes through superficial inguinal ring- protrudes
outwards.
• Direct inguinal hernia: piece of organ pushes
directly ant. Abd. wall passes through supeficial
inguinal ring – protrudes outwards.
• How to differentiate direct and indirect ingunal
hernia?
reference is the inferior epigastric artery.
• If it is lateral to this a. :Indirect inguinal
hernia
• If it is medial to this a.: Direct inguinal hernia.
Femoral canal
Femoral hernia
(saphenus opening)
Folds of the ant. Abd. wallperitoneum
• When looked from inside the anterior abdominal
wall there are some folds of parietal peritoneum :
• Median umbilical fold : under which lies the
urachus
• Medial umbilical fold: under which umbilical
artery lies.
• Lateral umbilical fold: inferior epigastric
vessels lie.
ARTERIES, VEINS and LYMPH OF
THE ANT. ABD. WALL
• Arteries: Sup. Epigastric. A.+ ınferior epigastric
a.+ superficial circumflex iliac a.+ deep
circumflex iliac a.+ superficial epigastric
a.+musculophrenic
• Veıns: SAME NAMED.
• IMPORTANT ANASTOMOSIS: supeficial
epigastric vein- lateral thoracic vein- unite the
veins of the superior and inf. Halves of the body.
• Lymph: Axillary-above the umbilical region
Inguinal- below the umbilical region.
Lymphatics of the
abdominal wall