Posted by JR on August 29, 2011 at 19:28:18:
In Reply to: Abdominal Wall posted by isz on August 27, 2011 at 10:46:13:
Abdominal Wall
1. Define an aponeurosis.- Flat sheets of tendon that anchor the muscle to the skeleton, deep fascia, or aponeurosis of another muscle.
2. What is the linea alba?- A midline seam extending from the xiphoid to the pubic symphisis formed from an interweaving of the right and left rectus sheaths. Both the anterior and posterior portions are included in the fusion.
3. Discuss the composition of the rectus sheath in the upper 3/4'and lower 1/4 of the body. Upper ¾: anterior consists of external oblique and internal oblique. Posterior consists of internal oblique, transversus abdominus, and transversalis fascia. Lower ¼: Anterior consists of external oblique, internal oblique, transversus abdominus. Posterior consists of transversalis fascia.
4. What is the arcuate line?- a crescentic line that demarcates the transition between the aponeurotic posterior wall of the sheath covering the superior three quarters of the rectus and the transversalis fascia covering the inferior quarter.
5. Define the origin, insertion, innervation, and vasculature of the rectus abdominis, external oblique, internal oblique, and transversus abdominis muscles.
Rectus abdominis: O: Pubic symphisis and pubic crest I: Xiphoid process and 5-7 costal cartilages. Nerve: Thoracoabdominal nerves (anterior rami of t6-t12 spinal nerves)
External Oblique: O: external surfaces of 5th through 12th ribs I: Linea alba, pubic tubercle, and anterior half of iliac crest. Nerve: Thoracoabdominal nerves (t7-t11 spinal and subcostal nerve)
Internal Oblique: O: thoracolumbar fascia, anterior 2/3 of iliac crest, connective tissue deepto lateral third of inguinal ligament I: Inferior borders of 10-12 ribs, linea alba, and pectin pubis via conjoint tendon Nerve: Thoracoabdominal nerves (t6-t12 spinal and 1st lumbar nerve)
Transversus Abdominis: O: Internal surface of 7-12th costal cartilages, thoracolumbar fascia, iliac crest, and connective tissue deep to lateral third of inguinal ligament I: Linea alba with aponeurosis of internal oblique, pubic crest, and pectin pubis via conjoint tendon Nerve: Thoracoabdominal nerves (t6-t12 spinal and 1st lumbar nerve)
6. Discuss the course and interaction of the inferior epigastric and superior epigastric arteries. The superior epigastric artery is the direct continuation of the internal thoracic artery. It enters the rectus sheath superiorly through its posterior layer and supplies the superior part of the rectus abdominis and anastomoses with the inferior epigastric artery in the umbilical region. The inferior epigastric artery arises from the external iliac artery just superior to the inguinal ligament. It runs superiorly in the transversalis fascia to enter the rectus sheath below the arcuate line. It anastomoses with the superior epigastric artery in the lower rectus abdominis.
7. Define the location of Scarpa's fascia.- Inferior to the umbilicus, deep to camper’s fascia. It is continuous with the superficial perineal fascia in the perineal region.
8. What is Camper's fat? The fatty layer of subcutaneous tissue located superficial to scarpa’s fascia in the anterolateral abdominal wall.
9. What is inguinal ligament derived from? The inguinal ligament is derived from the external oblique aponeurosis.
10. Where do the nerves travel in the anterior abdominal wall? In the anterolateral portion of the abdominal wall, the nerves travel in the neurovascular plane between the internal oblique and transversus abdominis muscles. In the anterior portion, however, the nerves leave the plane and lie mostly in the subcutaneous tissue.
11. What are tendinous insertions?- Tendinous insertions mark the points at which the rectus abdominis is anchored transversely to the anterior layer of the rectus sheath. Typically there are three: one located at the level of the xiphoid, one at the umbilicus, and one in between.
12. What is the falciform ligament?- the ligament that attaches the liver to the anterior abdominal wall. It is derived from the ventral mesentery in the embryo.
13. What is the ligamentum teres - and what is its significance in embryology?- The round ligament of the liver is a degenerative string of tissue in the free edge of the falciform ligament that divides the liver into medial and lateral sections. It inserts around the umbilicus. It is the embryologic remnant of the left fetal umbilical vein which deteriorates a month or two after birth.
14. What is the median umbilical ligament?- a degenerated piece of tissue that extends from the apex of the bladder to the umbilicus. It is the remnant of the embryonic urachus.
15. What is the median umbilical fold?- a fold of peritoneum covering the median umbilical ligament.
16. What is the medial umbilical ligament?-the fibrous remnant of the umbilical artery.
17. What is the medial umbilical fold?-a raised fold of peritoneum on the anterior abdominal wall covering the medial umbilical ligament.
18. What is the lateral umbilical fold? – a raised fold of peritoneum covering the inferior epigastric artery
19. Is there a lateral umbilical ligament? –No….inferior epigastric artery is patent
20. What is the urachus?- a fibrous remnant of the allantois, a canal that drains the urinary bladder of the fetus and runs with the umbilical cord.
21. What does the obliterated umbilical artery represent in the fetus? Medial umbilical ligament?
22. What is the relationship of the umbilical folds and ligaments to the peritoneum, extraperitoneal connective tissue, and the transversalis fascia? –folds and ligaments are formed from peritoneum…deep to extraperitoneal connective tissue and transversalis fascia?