Anterior Abdominal Wall & Inguinal Region Flashcards
What are the superficial layers of abdominal fascia? What does the membranous layer attach to?
Camper’s fascia - superficial, fatty layer (forms beer belly)
Scarpa’s fascia - deep, membranous layer, well developed in lower abdominal wall, attaches to deep thigh fascia inferior to inguinal ligament
What are the deep layers of abdominal fascia?
- Fascial covering of the superficial + deep surfaces of the individual anterior abdominal wall muscles. Several of these coverings contribute to spermatic cord
- Transversalis fascia
What is the transversalis fascia?
The deep fascia covering the innermost surface of the deep anterior wall muscle layer, derived posteriorly from thoracolumbar fascia
What is the extraperitoneal fascia?
Analogous to endothoracic fascia, it is between the parietal peritoneum + transversalis fascia. It is also called extraperitoneal connective tissue
What is the origin, insertion, innervation, and action of the external abdominal oblique?
Origin: Ribs 5-12
Insertion: Iliac crest + linea alba through aponeurosis, forms inguinal ligament through lower extent
Innervation: Anterior rami of T7-T12 (lower 6)
Action: Compresses abdominal contents during maximal expiration, coughing, and defecation. Also rotates and flexes trunk
How are the fibers of the external abdominal oblique oriented?
Towards midline, like external intercostals
What is the inguinal ligament?
Ligament between the anterior superior iliac spine and pubic tubercle on both sides which forms from the external abdominal oblique aponeurosis
What is the origin, insertion, innervation, and action of the internal abdominal oblique?
Origin: Thoracolumbar fascia, iliac crest, lateral 2/3 of inguinal ligament
Insertion: Inferior border of ribs 9-12, and linea alba, pubic crest, and pectineal line (of ilium) through the aponeurosis
Innervation: T7-T12, plus L1
Action: Same as external oblique
What is the origin, insertion, innervation, and action of the transversus abdominis?
Origin: Thoracolumbar fascia, iliac crest, costal cartilages of lower few ribs
Insertion: Aponeurosis attaches to liena alba, pubic crest, and pectineal line
Innervation: T7-T12, plus L1
Action: Compression of abdominal contents only
What is the conjoined tendon?
Also called conjoint, it is the tendon formed by fused aponeurosis of internal abdominal oblique and transversus abdominis, which formed the medial posterior wall of the inguinal canal
What is the origin, insertion, innervation, and action of the rectus abdominis?
Origin: Pubic crest, pubic tubercule, and pubic symphysis
Insertion: Costal cartilages of ribs 5-12 + xiphoid process
Innervation: T7-T12
Action: Compression of abdominal contents + flex trunk
What is the rectus sheath?
Dense connective tissue enclosing the rectus abdominis muscle. The anterior and posterior layers are formed by aponeuroses of abdominal obliques + transverse abdominus muscles.
What are the linea semilunaris and linea alba?
White and semilunar lines in the rectus sheath.
Linea semilunaris - lateral edge of rectus abdominis
Linea alba - midline between rectus abdominis
How does the rectus sheath differ above and below the umbilicus? What is the major landmark called?
At some point between the umbilicus and pubic symphysis called the arcuate line, the posterior layer of the rectus sheath is absent, and the rectus abdominis is in contact with the transversalis fascia
What contributes to the anterior and posterior rectus sheaths? Where can this definitely be found?
Above the umbilicus:
External abdominal oblique aponeurosis: anterior only
Internal abdominal oblique aponeurosis: splits to anterior + posterior
Transversus abdominis aponeurosis: posterior only
What are the thoracoabdominal nerves?
Intercostal nerves (ventral rami of T7-T11) which continue into anterior abdominal wall
What is the subcostal nerve?
From anterior ramus of T12 which enters anterior abdominal wall
What are the iliohypogastric and ilioinguinal nerves?
From anterior ramus of L1 enters anterior abdominal wall