Anterior abdominal wall and the inguinal region Dr . Selda Önderoğlu

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 (

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

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

(

)

• -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 intra-

abdominal 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

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. wall- peritoneum

• 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