Chapter 5 The Section 1 Introduction Section 2 The anterolateral Section 3 The and peritoneal cavity Section 4 The organs which are related with peritoneal cavity Section 5 The retroperitoneal space Section 1 Introduction The abdomen is location between the thorax and perineum. It includes the abdomen wall, abdomen cavity and the organs of abdomenal cavity. Section 1 Introduction

Ⅰ. Boundaries 1. Superior border It is formed by the xiphoid process, costal archs, anterior ends of 11th ribs, lowers of 12th ribs and the 12th thorax vertebra. 2. Inferior border It is formed by the upper border symphysis, pubic crests, pubic tubercles, ligaments, iliac crests and the border of 5th lumber vertebra. Section 1 Introduction

Ⅱ. The abdominal cavity 1. Formation It is a cavity surrounded by diaphragm, pelvic diaphragm, the posterior and anterior walls of cavity. 2. Division It is divided into following two parts by inlet of lesser pelvic cavity. (1) Proper abdominal cavity - abdominal cavity: The cavity is above the inlet of lesser pelvic cavity. (2) Pelvic cavity: The cavity is below the inlet of the lesser pelvic cavity. Section 1 Introduction Ⅲ. The division of the abdominal wall and abdomen 1. The division of the abdominal wall (1) Anterior abdominal wall (or anterolateral abdominal wall): It is anterior to the posterior axillary line. (2) Posterior abdominal wall: The wall is posterior to the posterior axillary line. 2. The division of abdomen Section 1 Introduction

Ⅲ. The division of the abdominal wall and abdomen 2. The division of abdomen Two methods are used to divide the abdomen into different regions. (1) Four lines - nine divisions methods (2) Two lines - four divisions method Section 1 Introduction (1) Four lines - nine divisions methods: It uses four lines—two transverse and two vertical lines to divide the abdomen into 9 regions. Four lines ① Two transverse lines Superior transverse line (or subcostal line): It is drawn between the lower limits of costal arch. Inferior transverse line (or transtubercular line): The Superior abdominal part line is drawn between right and left tubercles on the iliac crests. middle abdominal part Two transverse lines divide the abdomen into three parts i.e. superior, middle and inferior. inferior abdominal part Section 1 Introduction

(1) Four lines - 9 regions. Four lines

① Two transverse lines

② Two vertical lines: Right & Left vertical lines.

Two vertical lines pass through the midpoint of inguinal ligaments.

Two vertical lines together Superior abdominal part with transverse lines divide abdomen into Nine regions. middle abdominal part

inferior abdominal part Section 1 Introduction

Nine regions

① Superior abdominal part: Epigastric region, Right & Left hypochondriac regions.

② Middle abdominal part: Umbilical region, Right & Left lateral (or lumber) regions.

Superior abdominal part ③ Inferior abdominal part: Hypogastric (or pubic, supropubic) region, Right & Left iliac (or inguinal) middle abdominal part regions .

inferior abdominal part Section 1 Introduction

Four quadrants

(2) Two lines four divisions method: passes through the umbilicus.

Vertical line Transverse line

RUQ RLQ LUQ LLQ Landmark (Two lines) • The : it is a linear depression in the median plane extending from the xipoid process to the pubic symphsis. The umbilicus is interposed in the linea alba at the level between the 3rd and 4th lumbar.

• The linea semilunaris: it indicated border of the rectus abdominais and its sheath. The point where this line meets the right 9th costal cartilarge indicates the position of the fundus of the gallbladder. Chapter 5 The Abdomen Section 1 Introduction Section 2 The anterolateral abdominal wall Section 3 The peritoneum and peritoneal cavity Section 4 The organs which are related with peritoneal cavity Section 5 The retroperitoneal space Section 2 The anterolateral abdominal wall

Position: anterior to the posterior maxillary line. Arrangement (from superficial to deep layer): 1- The skin 2- superficial fascia 3- Deep fascia and muscles (3+1) (transverse fascia) A plane 4- subperitoneal fascia (or extraperitoneal fascia) 5- parietal peritoneum BA plane

B Section 2 The anterolateral abdominal wall

Position: anterior to the posterior maxillary line. Arrangement (from superficial to deep layer): 1- The skin 2- superficial fascia 3- Deep fascia and muscles (3+1) (transverse fascia) 4- subperitoneal fascia (or extraperitoneal fascia) 5- parietal peritoneum 2- Superficial fasica 1- Skin Camper’s fascia Scarpa’s fascia

bbbbb bbbbb3- Deep fascia bbbband muscle layer (3)

external obliques muscle

internal obliques muscle

transverse muscle abdominis

4- subperitoneal fascia (or extraperitoneal fascia) 5- parietal peritoneum. Section 2 The anterolateral abdominal wall Superficial fascia

① Formation: It is formed by adipose tissue and loose connective tissue.

② The superficial fascia below the umbilicus can be divided into two layers superficial and deep. Superficial layer: is a fatty layer, also called Camper’s fascia. Deep layer: is a , also called Scarpa’s fascia. 1. Skin: thinner and more elastic 薄而富有弹性 2.The superficial fascia below the umbilicus can be divided into two layers superficial and deep. ① Superficial layer: is a fatty layer, also called Camper’s fascia. The superficial fascia below the umbilicus can be divided into two layers superficial and deep. ① Superficial layer: is a fatty layer, also called Camper’s fascia. ① Superficial fascia is a fatty layer, also called Camper’s fascia.  ②Deep layer is Scarpa’s fascia，is a membranous layer. It lies immediatedly superficial to the of the external oblique muscle. It is more membranous and continues with superficial fascia of penis, dartos of and superficial fascia of perineum (or Colle’s fascia) inferiorly.  Deep layer is Scarpa’s fascia，is a membranous layer. It lies immediatedly superficial to the aponeurosis of the external oblique muscle. It is more membranous and continues with superficial fascia of penis, dartos of scrotum and superficial fascia of perineum (or Colle’s fascia) inferiorly.  Deep layer is Scarpa’s fascia，is a membranous layer. It lies immediatedly superficial to the aponeurosis of the external oblique muscle. It is more membranous and continues with superficial fascia of penis, dartos of scrotum and superficial fascia of perineum (or Colle’s fascia) inferiorly. The contents of superficial fascia The superficial fascia contains superficial blood vessels, lymphatic vessels and cutaneous nerves. ⑴Superficial arteries The branches of posterior intercostals arteries, subcostal arteries and lumber arteries: They distribute to the lateral abdomen wall. The branches of superior and inferior epigastric arteries: They distribute the part of anterior abdominal wall which is near to the median line. The superficial epigastric artery and circumflex artery: They distribute to the lower part of the anterior abdominal wall. ⑵Superficial veins The veins above the level of umbilicus to the thoracoepigastric veins which drain to the axillary vein. The veins below the level of umbilicus to the superficial epigastric veins which drain to the great saphenous vein. The venous plexus around the umbilicus drain to the paraumbilical veins which drain to the hepatic portal vein. The contents of superficial fascia ⑶Superficial lymphatic vessels The lymph above the level of umbilicus drain to the axillary lymph nodes. The lymph below the level of umbilicus drain to the superficial inguinal lymph nodes. ⑷The cutaneous nerves The skin of anterior abdominal wall is supplied by the anterior and lateral branches of 7th to 11th intercostals nerves and subcostal nerves and (first lumbar nerve). They are aranged in following serial order. 7th intercostal nerve (T7) →distributes to the skin near the xiphoid process. 10th intercostal nerve (T10) →distributes to the skin at the level of the umbilicus. Iliohypogastric nerve (L1) →distributes to the skin above the (or an inch above the superficial inguinal ring and other at propotionate distance between them). Clinical correlates Deep layer is a membranous layer, also called Scarpa’s fascia. It ends by being attached to the fascia lata (i.e., deep fascia of the thigh) along a line 2 cm below the inguinal ligament. Medially, it ends by being attached to the linea alba. Between and , it is continues with superficial fascia of penis, dartos of scrotum and superficial fascia of perineum (or Colle’s fascia). There is a potential space between Scarpa’s fascia and the aponeurosis of the external oblique.

• If the penile urethra is injured (perineal injuries in car accidents; falling astride onto sharp objucts such as fence poles, etc.), urine may escape from the urethra into the scrotum. From there it may readily spread superiorly into the lower abdominal wall between Scarpa’s fascia and the aponeurosis of the external oblique. This is called urinary extravasation. • The urinary extravasation may be dramatic with extensive, red edematous swelling of the scrotum, penis, and lower abdominal wall. Of course, urinary extravasation into the thigh and the opposite side do not occur. Section 2 The anterolateral abdominal wall Deep fascia and muscles (3+1) (transverse fascia)

The three flat muscles are the: – external oblique muscle – internal oblique muscle – transversus abdominis And one is the – rectus abdominis Specimen of abdominal muscle transversus internal oblique abdominis muscle

external oblique muscle

rectus 4~5 smaller bellies abdominis fibrous inscriptions external oblique muscle internal oblique muscle transversus abdominis rectus abdominis

Superficial ring is a triangular hiatus of the aponeurosis of exrternal oblique, immediately supralateral to pubic tubercle. Medial crus: Latheral crus: Intercrural fibers: Inguinal ligament is formed by the lower border of the aponeurosis of exrternal oblique which is inserted to the anterior superior iliac spine and pubic tubercle. external oblique muscle internal oblique muscle transversus abdominis rectus abdominis

Inguinal falx (conjoined tendon) is formed by the lower margins of the internal oblique & transversus abdominis arch over the deep inguinal ring (roof of the inguinai canal) and becoming appneurotic, fuse to form the conjoined tendon. This tendon turns downwards between transverse fascia and to be attached to the pubic crest and the pecten pubis at the angles to the lacunal ligament. is formed by the lower muscular part of the internal oblique & transversus abdominis. It directs downwards and covers the . external oblique muscle internal oblique muscle transversus abdominis

rectus abdominis

The paired vertical rectus abdominis muscles are typically subdivided into 4~5 smaller bellies by tendinous intersections (fibrous inscriptions). The are formed by the close fibrous connective tissue. They connect with the anterior layer of the tightly and is very difficult separate them from each other. The blood vessels, lymphatic vessels and nerves (Ⅰ) Arteries between the internal oblique and transversus muscle include following arteries. 7th to 11th poserior intercostal arteries. Subcostal arteries. Superior epigastric arteries: Inferior epigastric arteries: Deep circumflex iliac artery: (Ⅱ) Veins: accompany with the corresponding arteries. . (Ⅲ) Lymphatic drainage: (Ⅳ) Nerves supply Anterior branches of the 7th to 12th thoracic nerves Iliohypogastric nerve Genital branch of the Section 2 The anterolateral abdominal wall Rectus abdominis & rectus sheath

The paired vertical rectus abdominis muscles are typically subdivided into 4~5 smaller bellies by fibrous inscriptions. Each muscle is located in a thick, strong sheath formed from the aponeurosis of the paired flat abdominal muscles.

The structure varies the upper 3/4 vs. lower 1/4. Section 2 The anterolateral abdominal wall Rectus abdominis & rectus sheath

•upper 3/4

•lower 1/4

arcuate line

represents the inferior margin of the posterior rectus sheath and typically is found half way between the umbilicus and the pubic symphysis. Section 2 The anterolateral abdominal wall Rectus abdominis & rectus sheath

•upper 3/4 – the key is the aponeurosis of the internal oblique which splits to contribute to both the anterior & posterior sheath; thus the external oblique aponeurosis must pass anterior and the transversus abdominis aponeurosis must pass posterior to the muscle respectively •lower 1/4 – all aponeurosis pass anterior to the rectus abdominis; thus there is only anterior rectus sheath here; only transversalis fascia, extraperitoneal CT & parietal peritoneum are present posteriorly Section 2 The anterolateral abdominal wall Inguinal region: Inguinal canal and Inguinal triangle

The inguinal canal is an oblique passage through the inferior anterior abdominal wall, but superior to the inguinal ligament. The 4~5 cm oblique canal serves as a route for structures to enter and leave the abdomen. The canal may be compared to a tunnel with 4 walls and 2 rings.

anterior wall – external oblique aponeurosis. floor – poterior wall – roof – superficial (external) ring – triangular opening in the external abdiminal oblique aponeurosis. deep (internal) ring – Contents – both sexes: ilioinguinal nerve Female: Male: spermatic cord Section 2 The anterolateral abdominal wall Inguinal region: Inguinal canal and Inguinal triangle

The inguinal canal is an oblique passage through the inferior anterior abdominal wall, but superior to the inguinal ligament. The 4~5 cm oblique canal serves as a route for structures to enter and leave the abdomen. The canal may be compared to a tunnel with 4 walls and 2 rings.

anterior wall – floor – the inguinal ligament as the rolled under inferior edgs of the external abdiminal oblique aponeurosis, and the lacunal ligament medially. poterior wall – roof – the internal oblique and transversus abdominis muscles arch over the canal. superficial (external) ring – deep (internal) ring – Contents – Section 2 The anterolateral abdominal wall Inguinal region: Inguinal canal and Inguinal triangle

The inguinal canal is an oblique passage through the inferior anterior abdominal wall, but superior to the inguinal ligament. The 4~5 cm oblique canal serves as a route for structures to enter and leave the abdomen. The canal may be compared to a tunnel with 4 walls and 2 rings.

anterior wall – floor – poterior wall – transversalis fascia and parietal peritoneum roof –. superficial (external) ring – deep (internal) ring – formed by an outpouching of the transversalis fascia, lies supeior to the midpoint of the inguinal ligement, the inferior epigastric vessels lie medial to the ring. Contents – Section 2 The anterolateral abdominal wall Inguinal region: Inguinal canal and Inguinal triangle

Inguinal or Hessebach’s triangle

Region on the inner, inferior portion of the abdominal wall, that is the site of direct inguinal .

The boundaries are: inferior = inguinal ligament medial = lateral border of lateral = inferior epigastric vessels Section 2 The anterolateral abdominal wall Clinical correlates inguinal The inguinal region is the most common site for hernias in both males and females. A hernia is defined as the protrusion of a structure or organ through a normal or abnormal opening. Two types of occur. Indirect inguinal hernias occur in males, from childhood to young adulthood, and generally are belived to have a congenital basis. The hernia enters or takes the path of the process vaginalis. passes through the inguinalcanal and is more likely to exit the superficial ring to enter the scrotum exit point is the deep inguinal ring lateral to the inferior epigastric vesels is covered by the fascial coverings of the spermatic cord and thus is within the cord Direct inguinal hernias occur in middle aged or older males, and believed to be due in part to the loss of muscle tone of the lower abdomonal wall. It is throught this weakens the ―shutter-like‖ action of the arching fibers of the internal oblique and transversus abdominis muscles during lifting, defecation, etc. exit point is through the inguinal triangle medial to the inferior epigastric vessels enters to the inferior wall of the canal and rarely exit the superficial ring is covered by peritoneum and transversalis fascia and lies adjacent to the cord rare in females Layer ?

Subcostal incision Median or midline incision

Muscle-splitting incision Left paramedian incision

Transverse incision Suprapubic incision Section 2 The anterolateral abdominal wall Dissection and observation At page 58~60 of Laboratory guide

Ⅰ) Position and Incisions 1. Put the cadaver in the supine position. 2. Make a midline skin incision from the xiphoid process to the pubic symphysis, encircling the umbilicus. 3. Mark another incision from the lower end of the median incision along the inguinal ligament to the posterior axillary line. Reflect the skin flaps till the posterior axillary line to expose the superficial fascia. 4. Make a transverse incision through the entire thickness of the superficial fascia from the xiphoid process to the posterior axillary line, then to the anterior midline along the ilica crest. Afterwards, make a longitudinal section through the fascia at a distance of 2cm from the midline between the two incisions.

Dissection and Observation Ⅱ) Procedures

Superficial structures Three flat muscles, vessels and nerves rectus abdominis & rectus sheath inguinal region inguinal canal inguinal triangle 1.切口 Incision

2.将皮瓣翻向外侧 reflect skin flaps laterally.

3. Identify the fatty layer of the superificial fascia.

4.Identify the superficial epigastric vessels.

5.Remove the superficial fascia.

6. Identify the membranous layer of the superficial fascia. 7. Identify several anterior cutaneous branches of the lowest five intercostal nerves (T7~T11)and the subcostal nerve (T12). 8. Identify the terminal branches of the iliohypogastric nerve (L1) and the ilioinguinal nerve (L1). 9. Remove deep investing covering the external abdominal oblique muscle. 10.Identify the direction of the fibers and the aponeurosis of the external abdominal oblique muscle. 11.Identify the inguinal ligament, the superficial inguinal ring, the medial crus, the lateral crus and the intercrural fibers. 12.Reflect the external abdominal oblique and expose the internal abdominal oblique. Reflect the internal abdominal oblique and expose the transversalis muscle. 13.Identify the vessels and nerves. 14.Cut through the anterior layer of the rectus abdominis. 15.Identify the muscular part and tendinous part of the rectus abdominis, and the pyramidal muscle. 16.Free the lateral edge of rectus abdominis, and make a horizontal incision through the entire width of the rectus abdominis muscle at the level of the umbilicus. Reflect the segments of transected muscle superiorly and inferiorly. 17. Identify the superior and inferior epigastric vessels, the intercostal and subcostal nerves, the posterior layer of the rectus sheath and the arcuate line. 18. Dissect the inguinal region. Identify the iliohygogastric nerve, the ilioinguinal nerve, the transverse fascia and the inferior epigastric artery. 19. Identify the two openings and four walls of the inguinial canal. 20. Dissect the spermatic cord and identify its components . 21. Identify five folds of the peritoneum and fossae located on the inner surface of the anterior abdominal wall. Homework (at page 199~200 of Textbook)

Ⅰ. Define the following terminologies 1~13

Ⅱ. Answer the following questions. 1~3, 5