Written Examination Part III. (34 pts) - Short Answer: Abdomen, Pelvis, and Perneum (September 21, 2006)

Perineal Body

• Also known as the central tendon of the perineum. Pyramid shaped mass of fibromuscular tissue between anal canal and the vagina or bulb of the penis. Muscles that terminate in it. Larger in female. The base of the perineal body rests against the skin and its apex points into the urogenital hiatus. Muscle fibers that are interlaced in it include the puborectalis, external sphincter urethrae, external anal sphincter, deep transverse perineal, bulbospongiosus and superficial transverse perineal. Capable of extreme stretching, however to avoid tearing during childbirth, it will often be cut. Called an episiotomy.

Transverse Perineal Ligament

• Associated with the superior and inferior fascia of the Urogenital diaphragm. They blend together at the anterior margin of the U.G. diaphragm to form a ligament between the conjoint rami of the ischium and pubis. It is the inferior border of a gap which transmits either the deep dorsal vein of the penis or clitoris as it travels from the pelvis to the perineum. The structure arches superiorly over the sphincter urethrae.

Epiploic Foramen

• Anterior - Hepatoduodenal ligament
• Posterior- inferior vena cava
• Superior - caudate lobe of liver
• Inferior - First part of the duodenum and Pancreas
• Right - Opening into the hepatorenal recess and right paracolic gutter
• Left - Vestibule of the lesser sac

Tunica Vaginalis

• An extension of the peritoneal sac into the scrotum. It does not communicate with the peritoneal cavity which is obliterated following the neonatal period. It has both a parietal layer and a visceral layer. A site for hydrocele formation. The visceral layer bound to the anterolateral surface of the testis. The parietal layer is fused to the internal spermaticfascia. It is not locate posteriorly. A congenital indirect hernia is the product of a patent vaginalis. An acquired indirect is the result of a patent vaginalis of variable length.

Arcuate Line

• Three flat muscles contribute to the formation of the abdominal wall. The anterior tendons fuse together to form the Linea Alba at the anterior midline. This aponeurosis forms around the rectus abdominis with the tendon of the external oblique superficially, splits the tendon for the internal oblique, and the transversus abdominis deep to the rectus abdominis above the umbilicus. Located on the anterior wall of the abdomen below the umbilicus is a concave or downward crescent shaped border that indicates a transition of the internal oblique and transversalis aponeurosis from deep to the rectus abdominis muscle to superficial. Located below the umbilicus, or below approx. L4. At this point Rectus abdomonis is in contact with endoabdominal (transversalis) fascia. Inferior epigastric artery and vein pass deep to this line as they course through the transversalis fascia and terminate in the rectus abdominis muscle. There are two arcuate lines located lateral to the Linea Alba.

Porta Hepatis

• Transverse fissure located between the neck of the gallbladder and the junction of the fissures for the ligamentum teres and ligamentum venosum. The following structures are transmitted through it hepatic artery, portal vein, hepatic ducts. At the right limit of the porta hepatic two leaves of the lesser omentum come together to form the hepatoduodenal ligament. The inferior vena cava is located posteriorly.

Lienorenal Ligament

• Also called the splenorenal ligament or omenta. The ligament is a superior continuation of the omentum above the colon on the left side. Derived from dorsal mesentery. Left posterior boundry of lesser sac. Tethered to the surface of the left kidney and immobilizes the tail of the pancreas to the posterior wall. Allows the passage of arterial, venous, and lymphatic vessels and nerves to structures in intraperitoneal. Contains the splenic artery and continuous with the gastrolienal ligament.

Medial Inguinal Fossa

• A site for direct inguinal hernias. The fossa is located between the medial umbilical folds containing the medial umbilical ligaments and the lateral umbilical fold containing the inferior epigastric arteries. The medial umbilical ligaments that make up the medial folds are continuations of the parietal peritoneal tissue between the bladder and the anterior abdominal wall.

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