Abdomen

• Umbilicus


  Level of IVD of L3 - L4
• Subcostal plane


  10th rib; L3
• Transtubercular


  Iliac tubercle; L5
• Nine abdominal regions


  • Epigastric
  • Umbilical
  • Hypogastric / Pubic
  • R/L Hypochondriac
  • R/L Lumbar
  • R/L Inguinal
• Fasciae of the anterior abdominal wall

  • Superficial fascia
  • Deep fascia
• Deep fascia


  • Covers the muscles and continues over the spermatic cord as the External spermatic fascia; continues over the Penis as the deep fascia (BUCK's fascia) and perineum as deep perineal fascia
• Abdominal muscles


  • 4 paired
  • 3 flat
  • 1 strap-like
• Abdominal muscles


  • Strengthen abdominal wall
  • Decrease risk of protrusion of viscera
• External oblique


  • Most superficial
  • Free inferior margin = inguinal ligament
  • Interdigitate w/ serratus anterior and latissimus dorsi
  • Obliquely downward and medially
  • Form aponeurosis
• Internal oblique


  • Deep to external oblique
  • Upward and medial
  • Aponeurotic fibers of int oblique and transversus abdominis = Conjoint tendon
  • Form aponeurosis w/c splits to form rectus sheath
• Transversus abdominis


  • Innermost
  • Flat
  • Ends in aponeurosis
  • Contribute to conjoint tendon
• Superficial Fascia


  • Fatty Layer / CAMPER's fascia - merges with superficial fascia of the thigh and superficial layer of the perineal fascia
  • Membranous Layer / SCARPA's fascia
• Rectus Abdominis


  • On either side of linea alba
  • Segmented = tendinous intersections
  • Lateral borders convex = Linea semilunaris
• Pyramidalis


  • Not always present
  • Tenses linea alba
• Above the Arcuate Line

  1. Anterior rectus sheath: external oblique (EO) aponeurosis + internal oblique (IO) aponeurosis

  2. Posterior rectus sheath: transversus abdominis (TA) aponeurosis + IO aponeurosis
• Below the Arcuate Line

  1. Anterior rectus sheath: aponeurosis of EO + IO + TA

  2. There is NO posterior layer of the rectus sheath
• Arcuate Line


  • Crescent shaped line marking the inferior limit of the posterior layer of the Rectus sheath
  • Midway between umbilicus and pubic crest
  • Linea semicircularis – other name
• Linea Alba


  • A tendinous median raphe between the two Rectus Abdominis muscles, formed by the fusion of the aponeuroses of the External oblique, Internal oblique and Transversus abdominis muscles
  • Extends from the Xiphoid process to the Pubic symphysis
• Contents of Rectus Sheath

  • Rectus abdominis
  • Pyramidalis
  • Superior epigastric vessels
  • Inferior epigastric vessels
  • Lower 5 intercostal and subcostal vessels & nerves
• Blood Supply

  • Superior Epigastric – from Internal thoracic artery
  • Inferior Epigastric – from External iliac artery
  • Deep circumflex iliac – from External iliac artery
  • Superficial Epigastric – from Femoral artery
  • Superficial Circumflex Iliac – from Femoral artery
• Ventral rami of the lower six thoracic nerves and First Lumbar nerve


  • Nerve supply to the anterior abdominal wall
• Lymphatic drainage of the anterior abdominal wall


  • Region ABOVE the Umbilicus - drain into Axillary LN
  • Region BELOW the Umbilicus - drain into the Superficial Inguinal nodes
  • Superficial Inguinal LN - receive lymph from the lower abdominal wall, buttocks, penis, scrotum, labia majora and the lower parts of vagina and anal canal - enter the External iliac nodes and ultimately to the Lumbar nodes
• After surgical repair of a hernia

  Patient experiences numbness in the skin on the anterior aspect of the scrotum
• Region above the umbilicus

  • Drain into axillary lymph nodes
• Region below the umbilicus


  • Drain into the superficial inguinal nodes
• Superficial inguinal lymph nodes

  • Receive lymph from the lower abdominal wall, buttocks, penis, scrotum, labia majora and the lower parts of vagina and anal canal
  • Enter the external iliac nodes and ultimately to the lumbar nodes
• Inguinal region (groin)


  Extends between ASIS and pubic tubercle
• Inguinal region (groin)


  • Where structures exit & enter abdominal cavity = potential sites of herniation
• Inguinal triangle (Hesselbach)


  Boundaries:

  Inf. Epigastric artery – superior & lateral

  Inguinal ligament / Poupart ligament – inferior & lateral

  Rectus Abdominis – medial
• Inguinal Canal


  • 11⁄2in(4cm)long
  • From deep inguinal ring (hole in fascia transversalis) to superficial inguinal ring (hole in external oblique aponeurosis)
  • Parallel & immediately above inguinal ligament
• Walls of Inguinal Canal

  • Anterior - EOM aponeurosis
  • Posterior - Transversalis fascia & Conjoint tendon
  • Superior/Roof - IO & TA
  • Inferior/Floor - Inguinal ligament
• Males


  Spermatic cord
• Females


  Round ligament
• Common structure


  Ilioinguinal nerve
• Spermatic Cord


  • Contains the following structures:
  • vas deferens
  • testicular artery
  • testicular veins (pampiniform plexus)
  • testicular lymph vessels
  • autonomic nerves
  • processus vaginalis
  • cremasteric artery
  • artery of vas deferens
  • genital branch of genitofemoral nerve
• 3 Arteries → testicular artery, cremasteric artery, artery of vas deferens 2 Nerves → autonomic nerves, genital branch of genitofemoral nerve

  2 Others → vas deferens, processus vaginals

  1 Vein → testicular veins

  1 Lymphatic vessel → testicular lymph vessels

  Make sure your total content is always 9 in number.
• Structures in the spermatic cord

  • 3 Arteries
  • 2 Nerves
  • 2 Others
  • 1 Vein
  • 1 Lymphatic vessel
• Arteries in the spermatic cord


  • testicular artery
  • cremasteric artery
  • artery of vas deferens
• Nerves in the spermatic cord

  • autonomic nerves
  • genital branch of genitofemoral nerve
• Other structures in the spermatic cord

  • vas deferens
  • processus vaginals