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

umbilical (around the umbilicus) 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 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 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: 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. 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