08腹壁及腹腔探察ppt課件

1、Dissection of Anterior Abdominal WallWith the cadaver in the supine position, incise the skin in the midline from the xiphisternal joint to the pubic symphysis, cutting around the umbilicus. Then incise the skin 1 inch above the pubis symphysis laterally over to and a little above the iliac crest to

2、 the midaxillary line on both sides. Reflect the skin from the midline anteriorlly to the midaxillary line, leaving the superficial fascia on the anterior abdominal wall.Identify the fatty layer of the superficial fascia ( Campers fascia)and note that it is continuous below with the fatty superficia

3、l fascia of the thigh and above with the superficial fascia of the thorax. Note that the fat is greatest in amount over the inferior half of the abdomen.Note also the terminal portion of the superficial arteries and cutaneous nerves in this layer; also observe the superficial veins.Identify the Memb

4、ranous Layer of the Superficial Fascia (Scarpas Fascia). Note That It Lies Deep to the Fatty Layer and Immediately Superficial to the aponeurosis of the External Oblique Muscle. Insert a Finger Between the Membranous Layer and the aponeurosis of the External Oblique and Separate Them Inferiorly.Note

5、 That the Finger Can Be Passed Down Medial to the Pubic Tubercle Along the Spermatic Cord and Anterior to the Body of the Pubis Into the Perineum.Lateral to the Pubic Tubercle the Finger Cannot Enter the Thigh, However,since the Membranous Layer Is Attached to the Deep Fascia of the Thigh Just Below

6、 the Inguinal Ligament.Identify the Superficial Inguinal Ring Above the Pubic Tubercle but Do Not Disturb It at This Stage. The Ring Is a Triangular Opening in the aponeurosis of the External Oblique Muscle.Make a vertical incising through the full thichness of the superficial fascia from the xiphoi

7、d process to the symphysis pubis. With the aid of a scalpel handle, carefully reflect the flaps of fascia laterally, separating the fascia from the aponeurosis of the external oblique muscle. Identify examples of anterior and lateral cutaneous nerves. Remove all the flaps of superficial fascia by ma

8、king a vertical incision through the fascia in the midaxillary line.External oblique muscle. Clean the surface of the external oblique muscle and its aponeurosis. Note the attachment of the fleshy origin from each of the lower eight ribs. Here it interdigitates with the origin of the serratus anteri

9、or and the latissimus dorsi.Observe the direction of the muscle fibers. Identify the linea alba that extends from the xiphoid process down to the symphysis pubis and is formed by the fusion of the aponeurosis of the muscle of the two sides.Carefully define the margins of the superficial inguinal rin

10、g lying above the pubic tubercle. Note that it is triangular in shape and not round. In the male, identify the spermatic cord emerging from this aperture and confirm that its outer covering, the external spermatic fascia, is attached to the margins of the ring. In the female, the round ligament of t

11、he uterus emerges from the ring. Again confirm that its outer covering is attached to the margin of the ring. Identify the ilioinguinal nerve as it emerges from the lateral part of the superficial inguinal ring. Identify the inguinal ligament and note that it is formed by the lower margin of the apo

12、neurosis of the external oblique muscle. The ligament is attached laterally to the anterior superior iliac spine and medially to the pubic tubercle. Attached to the lower margin of the ligament is the deep fascia.Internal Oblique Muscle. Free the interdigitating origins of the external oblique muscl

13、e from those of the serratus anterior as far as the midaxillary line. Incise the external oblique down the midaxillary line to the iliac crest. Now find the plane between the external oblique and the internal oblique muscles. With the fingers, free the external oblique from the internal oblique and

14、gradually turn the upper part of the external oblique forward. Note that the fibers of the internal oblique muscle run downward and backward, that is, at right angles to the fibers of the external oblique. Continue to reflect the external oblique forward and medially toward the lateral margin of the

15、 rectus sheath to fully expose the underlying internal oblique muscle. Study the origins and insertions of the external oblique and its innervation.Make a vertical incision through the aponeurosis of the external oblique muscle 1 inch lateral to the rectus sheath and extend it down to a point 3 inch

16、es above the pubic tubercle. Turn the inferior portion of the external oblique downward and carefully examine the superior surface of the inguinal ligament. It is most important that you understand the attachments and configuration of the inguinal ligament. Note that the ligament is the inrolled low

17、er margin of the aponeurosis of the external oblique and confirm again that it is attached to the pubic tubercle medially and the anterior superior iliac spine laterally. Carefully follow the inguinal ligament medially to the pubic tubercle, follow the fibers backward as the lacunar ligament, and no

18、te the attachment to the pectineal line. Note the continuity of the lacunar ligament with the pectineal ligament. Study the relationship of the inguinal, lacunar, and pectineal ligaments to the femoral sheath.Clean the surface of the internal oblique muscle. Define the inferior border of the muscle

19、and note its relationship to the spermatic cord or round ligament of the uterus. Study closely the origin of the internal oblique from the inguinal ligament. Note that the internal oblique fibers arise from the lateral half of the ligament and therefore lie anterior to the deep inguinal ring.Identif

20、y the cremaster muscle passing onto the spermatic cord from the lower edge of the internal oblique muscle. Clean the ilioinguinal nerve and follow it proximally to where it emerges from the internal oblique muscle.Exposure of transversus abdominis muscle. Cut through the attachments of the internal

21、oblique muscle to the costal margin and transect it vertically along the midaxillary line. Cut through the origin from the iliac crest and the inguinal ligament. Insert your fingers into the plane between the internal oblique and underlying transversus abdominis muscle. Reflect the internal oblique

22、muscle forward to the lateral margin of the rectus sheath to expose fully the underlying transversus abdominis muscle and the intercostal neres.At the lateral edge of the rectus abdominis, the aponeurosis of the internal oblique is seen to split and pass anterior and posterior to the rectus abdomini

23、s; the anterior layer fuses with the aponeurosis of the external oblique muscle, and posterior layer fuses with that of the transversus abdominis. This aponeurotic covering to the rectus abdominis is called the rectus sheath.Transversus abdominis muscle. Clean the surface of the transversus abdomini

24、s and the vessels and nerves that lie on it. Note that the fibers of the transversus muscle run in a horizontal direction. Identify the lower margins of the transversus abdominis muscle and follow its fibers medially to join with those of the internal oblique to form the conjoint tendon. Examine the

25、 attachment of the conjoint tendon to pubic crest and the pectineal line. Note that the conjoint tendon lies immediately posterior to the superficial inguinal ring. Again examine the inguinal, lacunar, and pectineal ligaments and note their relationship to the conjoint tendon.Fascia transversalis. I

26、nsert the handle of the scalpel between the lower margin of the transversus abdominis muscle and the underlying fascia transversalis. Remember that this fascia lines the abdominal wall and forms the posterior wall of the inguinal canal lateral to the conjoint tendon. The fascia transversalis is tiss

27、ue-paper thin, and the extraperitoneal fat can be seen through it. Deep to the fat is the peritoneal lining of the abdominal cavity.Rectus Sheath. The rectus sheath is a long sheath that encloses the rectus abdominis muscle and pyramidalis muscle (if present) and contains the anterior rami of the lo

28、wer six thoracic nerves and the superior and inferior epigastric vessels and lymphatics. It is formed largely by the aponeurosis of the three anterolateral abdominal muscles.Open the entire length of the rectus sheath by a longitudinal incision just lateral to the linea alba. Identify the medial edg

29、e of the rectus abdominis muscle. Raise its medial edge and, with the finger or blunt end of the forceps, verify that it is possible to separate the rectus muscle from the posterior layer of the sheath. Note and preserve the nerves and vessels passing through the posterior wall of the sheath into th

30、e lateral part of the muscle.Reflect the lateral part of the anterior layer of the sheath by cutting free the attached tendinous intersections of the rectus muscle. Examine again the linea alba and realize that it is formed by the fusion of the aponeuroses of the three lateral muscles of the abdomin

31、al wall on the two sides. It extends from the xiphoid process down to the sympgysis pubis and separates the rectus abdominis muscles on the two sides.Understand What Is Meant by the Term linea semilunaris. This Is a Curved Ridge Formed by the Lateral Margin of the rectus abdominis Muscle.Clean the r

32、ectus abdominis and Identify the pyramidalis Muscle if Present. Transect the rectus Muscle at Its Middle and Raise the Upper and Lower Ends, Cutting the Nerves That Enter It. Identify the Superior epigastric Artery That Enters the rectus Sheath by Emerging From Beneath the Lower Margin of the Sevent

33、h Costal Cartilage and Passing Down Posterior to the rectus Muscle. Note also the inferior epigastric artery that ascends within the sheath from below. Verify the origin and insertion of the rectus abdominis and the pyramidalis muscles. Finally,remove both of these muscles.Carefylly examine the ante

34、rior and osterior walls of the rectus sheath and verify their formation from the aponeuroses of the anterior abdominal muscles. Note that the posterior wall ends below at the arcuate line, where the aponeuroses of the internal oblique and trasversus abdominis muscles pass anterior to the rectus musc

35、le. Cut free the attachments of the internal oblique and trasversus abdominis muscles from the costal margin. Incise the latter muscle along the midaxillary line to the iliac crest. Try to preserve the underlying peritoneum intact. Reflect all the abdominal muscles and the fascia transversalis infer

36、iorly as a unit by blunt dissection. Cut around the umbilicus to preserve its connection with the ligamentum teres of the liver.Deep inguinal ring. Before destroying the fascia transversalis in the inguinal region, pull on the spermatic cord or round ligament of the uterus from the anterior surface

37、and identify the deep inguinal ring and the internal spermatic fascia. Confirm that the deep ring lies lateral to the inferior epigastric vessels.The Abdominal CavityThe Abdominal CavityPeritoneum. Peritoneum. The peritoneum is a serous The peritoneum is a serous membrane lining the walls membrane l

38、ining the walls of the abdominal cavity and of the abdominal cavity and clothing the abdominal clothing the abdominal viscera. The parietal viscera. The parietal peritoneum lines the walls peritoneum lines the walls of the abdominal cavity, of the abdominal cavity, and the visceral peritoneum and th

39、e visceral peritoneum covers the abdominal organs. covers the abdominal organs. The peritoneum secretes a small The peritoneum secretes a small amount of serous fluid, which amount of serous fluid, which lubricates the surfaces of the lubricates the surfaces of the peritoneum and facilitates free pe

40、ritoneum and facilitates free movement between the viscera. movement between the viscera. The potential space between the The potential space between the parietal and visceral layers of parietal and visceral layers of the peritoneum is called the the peritoneum is called the peritoneal cavity.perito

41、neal cavity.The peritoneum has the following The peritoneum has the following important arrangements: important arrangements: 1. The peritoneal cavity is 1. The peritoneal cavity is divided into the greater and the divided into the greater and the lesser sac. The greater sac is the lesser sac. The g

42、reater sac is the main compartment, and it extends main compartment, and it extends across the whole breadth of the across the whole breadth of the abdomen and from the diaphragm to abdomen and from the diaphragm to the pelvis. The lesser sac is the the pelvis. The lesser sac is the smaller compartm

43、ent, and it lies smaller compartment, and it lies behind the stomach, as a behind the stomach, as a diverticulum from the greater sac; diverticulum from the greater sac; it opens through an oval window it opens through an oval window called the opening of the lesser called the opening of the lesser

44、sac, or the epiploic foramen.sac, or the epiploic foramen.2. A mesentery is a 2. A mesentery is a two-layered fold of two-layered fold of peritoneum that peritoneum that attaches part of the attaches part of the intestines to the intestines to the posterior abdominal posterior abdominal wall, and it

45、 includs wall, and it includs the mesentery of the the mesentery of the small intestine, the small intestine, the transvers mesocolon, transvers mesocolon, and the sigmoid and the sigmoid mesocolon.mesocolon.3. An omentum is a two-3. An omentum is a two-layered fold of layered fold of peritoneum tha

46、t attaches peritoneum that attaches the stomach to another the stomach to another viscus. The greater viscus. The greater omentum is attaches to omentum is attaches to the greater curvature of the greater curvature of the stomach, and it the stomach, and it hangs down like an apron hangs down like a

47、n apron in the space between the in the space between the coils of small intestine coils of small intestine and the anterior and the anterior abdominal wall. abdominal wall. It is folded back on It is folded back on itself and is itself and is attached to the attached to the inferiorborder of the in

48、feriorborder of the transverse colon. The transverse colon. The lesser omentum slings lesser omentum slings the lesser curvature the lesser curvature of the stomach to the of the stomach to the undersurface of the undersurface of the liver. The liver. The gastrosplenic omentum gastrosplenic omentum

49、(ligament) connects (ligament) connects the stomach to the the stomach to the spleen.spleen.4. The peritoneal ligaments 4. The peritoneal ligaments are two-layered folds of are two-layered folds of peritoneum that attach the peritoneum that attach the less mobile solid viscera to less mobile solid v

50、iscera to the abdominal walls. The the abdominal walls. The liver, for example, is liver, for example, is attached by the falciform attached by the falciform ligament to the anterior ligament to the anterior abdominal wall and to the abdominal wall and to the undersurface of the diaphragm. undersurf

51、ace of the diaphragm. The mesenteries, omenta, and The mesenteries, omenta, and peritoneal ligaments allow peritoneal ligaments allow blood vessels, lymphatics, blood vessels, lymphatics, and nerves to reach the and nerves to reach the various viscera.various viscera.Opening of Abdominal Opening of

52、Abdominal cavity and Inspection of cavity and Inspection of Its Contents.Its Contents.When the peritoneal cavity When the peritoneal cavity has been opened by making a has been opened by making a transverse incision through transverse incision through the parietal peritoneum the parietal peritoneum

53、lining the anterior lining the anterior abdominal wall at the level abdominal wall at the level of the umbilicus, identify of the umbilicus, identify three folds of peritoneum three folds of peritoneum that converge on the that converge on the umbilicus from below. These umbilicus from below. These

54、cover the two lateral cover the two lateral umbilical ligaments and the umbilical ligaments and the median umbilical ligament. median umbilical ligament. Below the level of Below the level of the anterior the anterior superior iliac superior iliac spines, two spines, two additional folds additional

55、folds may be recognized, may be recognized, due to the due to the underlying underlying inferior inferior epigastric epigastric arteries.arteries.Examine the falciform Examine the falciform ligament, which extends ligament, which extends from the umbilicus to the from the umbilicus to the l i v e r

56、. I d e n t i f y t h e l i v e r . I d e n t i f y t h e ligamentum teres in the ligamentum teres in the f r e e m a r g i n o f t h e f r e e m a r g i n o f t h e falciform ligament. Cut the falciform ligament. Cut the peritoneum along the costal peritoneum along the costal margin, except where t

57、he margin, except where the falciform ligament of the falciform ligament of the liver is attached. Reflect liver is attached. Reflect t h e r e m a i n d e r o f t h e t h e r e m a i n d e r o f t h e peritoneum inferiorly by peritoneum inferiorly by c u t t i n g i t d o w n t h e c u t t i n g i

58、t d o w n t h e midaxillary line on each midaxillary line on each side.side.Study the abdominal Study the abdominal viscera in situ. Note viscera in situ. Note the relative size, the relative size, shape, and position of shape, and position of all the abdominal all the abdominal organs in the organs

59、 in the undisturbed abdominal undisturbed abdominal cavity. It is important cavity. It is important to avoid any dissection to avoid any dissection at this stage. at this stage. Be prepared to find pathological Be prepared to find pathological changes that may have been changes that may have been re

60、sponsible for the persons death responsible for the persons death or that may be evidence of previous or that may be evidence of previous disease. For example, the disease. For example, the peritoneum may be studded by peritoneum may be studded by numerous secondary carcinomatous numerous secondary