Department of Human Anatom School of Medicine of Zhejiang University The Abdomen Xiaoming Zhang Department of Human Anatom School of Medicine of Zhejiang University

Introduction Formation: Abdominal wall, Abdominal cavity and contents Boundaries Superior boundary Inferior boundary Abdominal wall Anterior Abdominal Wall posterior abdominal wall Abdominal cavity Division

4 abdominal quadrants right epigastric region left epigastric region right hypogastric region left hypogastric region

9 abdominal regions hypogastric region

Anterior Abdominal Wall

Ⅲ.The abdominal wall The layers of the anterior abdominal wall: skin superficial fascia muscles transverse fascia extraperitoneal fascia parietal peritoneum

I Anterior Abdominal Wall Layers and structures Superficial structures 1.skin 2.superficial fascia superficial layer — Camper‘s fascia deep layer — Scarpa‘s fascia, Colles’ fascia 3.superficial vessels and cutaneous nerves

Superficial structures superficial arteries：three groups The branches of posterior intercostal A., subcostal A., and lumbar A. ； Superior and inferior epigastric A. ； Superficial epigastric A. and superfical iliac circumflex.

Superficial structures the superficial veins: —umbilical venous network above the umbilicus below the umbilicus Superficial lymphatic vessels: upper→axillary lymph nodes lower→superficial inguinal lymph nodes anastomise with the lymphatics of the liver the cutaneous nerves

I Anterior Abdominal Wall Deep Structures Deep fascia Muscular layers rectus abdominis the sheath of

anterior layer of the sheath is formed by the aponeurosis of the obliquus exter- nus and the ant. layer of the aponeurosis of the obliquus internus. The linea alba is extending between the xiphoid process and the pubic symphysis, formed by the decussating of the aponeu- roses of the three flat muscles.

The posterior layer of the sheath is formed by the aponeurosis of the trans- versus and the post. Layer of the aponeurosis of the obliquus internus. sheath is lack of at the arcuate line(about 4cm below the omphalo)

I Anterior Abdominal Wall Deep Structures Muscular layers obliquus externus abdominis linea alba) superficial inguinal ring reflected ligament external spermatic fascia Inguinal ligament lacunar ligament pectineal ligament(Cooper ）

(3) The internus abdominis —arises from the lateral 2/3 of the inguinal lig.,the iliac crest and the thoracolumbar fascia.The muscular fibers is replace by the aponeurosis(ant. And post. layers) at the lateral margin of the rectus. —cremaster —inguinal falx

(4) The transverse abdominis —arises from the lateral 1/3 of the inguinal lig.,the iliac crest and the thoracolumbar fascia and internal aspect of lower 6 costal cartilage. —cremaster —inguinal falx

—inguinal canal 1. position —parallel to,and above the inguinal lig —inguinal canal 1. position —parallel to,and above the inguinal lig. Immediately. About 4cm long. 2. Structures — two orifices (1) the deep inguinal ring lies a transverse finger breadth(2cm)above the midpoint of inguinal lig. formed by the transverse fascia. (2)sup. Inguinal ring formed by the aponeurosis of the obliquus externus. triangular defect in shape. medial and lateral crus

—four walls (1) ant. wall is mainly formed by aponeurosis of the obliquus ext.,and laterally is reinforced by the beginning part of the obliquus internus. (2) inf. wall is formed by the inguinal ligament (3) Post.wall is formed by the transverse fascia, inguinal falx and the reflected lig.. (4) Sup. wall is formed by the arched fibers of the obliquus internus and transverse abdominis The contents male spermetic cord, ilioinguinal nerve female round ligament and ilioinguinal nerve

The inguinal triangle —boundaries inf. boundary medial half of the inguinal ligament medial boundary lateral border of the rectus abdominis lateral boundary inf. epigastric a.. **direct inguinal hernia

I Anterior Abdominal Wall Deep Structures extraperitoneal fascia parietal peritoneum Five longitudinal folds Median umbilical fold Medial umbilical fold Lateral umbilical fold inguinal medial fossa and inguinal lateral fossa

Summary of anterior abdominal wall Superficial structures skin superficial fascia :Camper and Scarpa superficial vessels and cutaneous nerves Deep Structures Deep fascia Muscular layers The vessels and nerves transversalis fascia extraperitoneal fascia parietal peritoneum

II Inguinal region Boundaries Superior boundary—from anterior iliac spine to lateral margin of rectus Medial boundary—lateral margin of rectus Inferior boundary—inguinal ligament inguinal trangle(Hesselbach trangle ） laterally —inferior epigastric A. medially —the lateral border of the rectus abdominis inferiorly —medial half of the inguinal ligament

III The incisions of anterolateral wall of abdomen

Rectus incision Median incision Inferior median incision McBurney’s incision

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