Anterior Abdominal Wall and Inguinal Region PDF

Anterior abdominal wall and the inguinal region Prof. Dr. Selda Önderoğlu Near East University Faculty of Medicine Department of Anatomy ABDOMEN The region between: Diaphragm and pelvis. Boundaries: Roof: Diaphragm Posterior: 5 Lumbar vertebrae...

Anterior abdominal wall and the inguinal region Prof. Dr. Selda Önderoğlu Near East University Faculty of Medicine Department of Anatomy ABDOMEN The region between: Diaphragm and pelvis. Boundaries: Roof: Diaphragm Posterior: 5 Lumbar vertebrae + Mm. Of the posterior abd. wall Inferior: No boundary, continuous with the pelvic cavity, Superior Pelvic aperture Anterior and lateral: Anterior Abdominal Wall , Muscles abdomen abdominal cavity bounded by the structures located at its boundarie Superior (Roof): Diaphragm; Posterior: Lumbar vertebrae+ Mm. Of the posterior abd. wall Inferior: No boundary, continuous with the pelvic cavity, Superior Pelvic aperture Anterior and lateral: Anterior Abdominal Wall , Muscles  Topography of the Abdomen (PLANES) For descriptive purposes the abdomen is divided by imaginary lines into 9 regions. These lines pass through certain structures 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&region s Of abdomen 9 regions: 1: umbilical (around the umbilicus) 2: epigastric; 3: hypogastric 4&5: L hypochondriac ; R hypochondriac 6&7:L inguinal ; R inguinal 8&9: L lumbar ; R lumbar Cutaneous nn. Of the anterior abdominal wall(Skin innervation) lower 5 intercostal nerves + subcostal nerve + L1 spinal nerve (ilioinguinal+iliohypogastric nn.). (all of those are anterior rami of spinal nerves) Umbilical region skin inn.: T10 Good reference!  Layers of 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 Just lateral to midline :rectus abdominis m. Transversalis fascia Extraperitoneal tissue layer (extraperitoneal fascia) peritoneum (the membrane covering some organs of the abdominal cavity. Muscles and layers of anterior&lateral abdominal wall 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 muscles are located mainly Laterally but their aponeurosis reach the midline&unite at linea alba) On both sides of the midline(linea alba) Rectus abdominis muscle inferiorly: Pyramidalis muscle Linea alba  External abdominal Oblique Muscle (M. Obliquus externus abdominis) Most superficially located 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: is the opening in the aponeurosis of external Oblique Muscle. has: Lateral crus-medial crus-  inguinal ligament: extends from anterior sup. iliac spine- to pubic sympyhsis; extends medially as lacunar ligament; to pectineal line as pectineal ligament Superficial inguinal Ring -Lat.crus -Medial crus -intercrural fibers  Internal abdominal 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 of this m. with the transversus abdominis muscle)+ Pubic crest+pecten pubis. Inn.:lower5 intercostal nn+subcostal n.+L1. (same with external oblique).  TRANSVERSUS ABDOMINIS MUSCLE Innermost muscle O: inf. 6 Costal cartilages+Thoracolumba r fascia+inguinal ligament I: conjoint tendon+linea alba. Innerv.:lower5 intercostal nn.+ subcostal n.+ L1. (same with external oblique) CONJOINT TENDON ( FALX INGUINALIS): common tendon of internal oblique+ transversus abdominis muscles TRANSVERSALIS FASCIA Located posterior (deep) to transv. Abd. m. has:deep inguinal ring.  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 (sternum) 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 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. Rectus sheath and Structures within the rectus sheath: rectus abdominis muscle+ superior epigastric artery+ inferior epigastric artery+ lower 5 intercostal nn.+ subcostal n. 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) -located medially Deep ingunal ring (transversalis fascia) - Located Laterally inguinal canal superficial inguinal ring Anterior wall Post. Wall Superior wall inferior wall deep inguinal ring 4-6 cm  WALLS of INGUINAL CANAL anterior :skin+ superficial fascia+external oblique (medially)+ internal oblique ( laterally). Posterior:Reflected ingunal lig.+conjoint tendon+ transversalis fascia. Inferior : inguinal lig.+ lacunar lig. Superior: 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 View of inguinal canal from internal aspect (from posterior aspect  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