Lecture 1, Anterior Abdominal Wall And Inguinal Sheath, 24

Define the borders of the abdomen ID osteological landmarks Costal margins Pubic tubercle Pubic symphysis ASIS Describe the layers of the abdominal wall Describe features of the external oblique muscle, incl. borders Innervation of external oblique Functions of external oblique muscle Borders of internal oblique Innervation of internal oblique Functions of internal oblique Features of the transversus abdominis muscle, incl. borders Innervation of transversus abdominis Functions of the transversus abdominis muscle Features of transversalis fascia Name the layers of the anteromedial wall Features of rectus sheath What is the arcuate line? ID linea alba ID arcuate line ID tendinous insertions ID rectus abdominis muscle Border of rectus abdominis Innervation of rectus abdominis Actions of rectus sheath

Diaphragm and pelvic inlet. Inferiorly, continuous with pelvic cavity

Skin, Camper’s fascia, Scarpa’s fascia, deep fascia, external oblique, internal oblique, transversus abdominis, tranversalis fascia, peritoneum Longest and most superficial muscle, muscular on lateral sides and aponeurotic medially, forms inguinal ligament and superficial inguinal ring, 5th rib to pubic tubercle Inferior thoracoabdominal nerves, T7-T12 Protects viscera, forced expiration, rotate and flex trunk Inguinal ligament to costal margin Inferior 6 thoracoabdominal nerves and 1st lumbar nerve Similar to external oblique muscle, also has an aponeurosis at the medial portion and fibers spread out like a fan Innermost muscle, fibers run horizontal, forms conjoint tendon, medial portion is aponeurotic, borders are 7th costal cartilage to pubis Same as internal oblique Compress and support viscera, forced expiration Membranous sheet made out of CT, forms deep inguinal ring Skin, superficial fascia, deep fascia, anterior rectus sheath, rectus abdominis muscle, posterior rectus sheath, transversalis fascia, parietal peritoneum 3 muscles end in the middle to form a sheetlike aponeurosis, 2 sides interlace at the linea alba The ending of the posterior rectus sheath creates the arcuate line Fibrous band created by interlacing of all 3 aponeuroses , contains umbilical ring The “lines” of the bricks on the rectus sheath, appears as linea semilunaris in surface anatomy Intermediate level of depth, located below the anterior rectus sheath 5th costal cartilage to pubis Inferior 6 thoracoabdominal nerves Flexes trunk, forced expiration

ID superior and inferior epigastric vessels Describe adult derivatives of fetal umbilical vessels ID umbilical folds Describe features and boundaries of inguinal canal ID deep inguinal ring ID spermatic cord, ductus deferens, and round ligament of uterus Describe how spermatic cord & testes got coverings Name the contents of the spermatic cord Name the borders of the inguinal triangle Describe the differences b/w direct and indirect inguinal hernia

Superior - from internal thoracic artery Inferior – from the external iliac artery Both arteries anastomose around the umbilical region 1 Median fold, covers median umbilical ligament 2 Medial umbilical folds, cover remnant fetal arteries 2 Lateral umbilical folds, cover inferior epigastric vessels Oblique passageway, runs inferior and medially Anterior: Aponeurosis of external oblique Posterior: Transversalis fascia Roof: Arching fibers of internal oblique and transverse abdominis Floor: Inguinal ligament Outpouching of transversalis fascia

Testes develop behind the peritoneum, gubernaculum attaches to the testes in the inguinal region of abdominal wall, testes descend follow the path of processus vaginalis  enter deep inguinal ring  through inguinal canal  out superficial ring  scrotum Ductus deferens, testicular artery, artery of the ductus deferens, cremaster artery, pampiniform plexus (venous plexus), sympathetic and parasympathetic nerve fibers, genitofemoral nerve, lymphatic vessels Inferior epigastric vessels, rectus abdominis, inguinal ligament Indirect: Caused by persistent processus vaginalis Outside of inguinal triangle Traverses entire inguinal canal Commonly enters the scrotum

Direct: Caused by repeated trauma and weakening of inguinal floor Through inguinal triangle Hernia traverses through part of inguinal canal Almost never in scrotum