Anterior Abdominal wall and Inguinal region Flashcards
what are the 3 layers of muscle that wrap around the lateral aspect of the abdomen
- External oblique
- Internal oblique
- Transverse abdominis
Describe external oblique
- its fibres run in a anterior-inferior direction.
- Most outer layer
- Attaches to the iliac crest
- Forms the inguinal ligament from the ASIS to the pubic tubercles
- Inferior border of external oblique is the inguinal ligament
- Muscle fibres end at the midclavicular line then becomes aponeurotic, insets at midpoint of the abdomen at the linea alba
describe internal oblique
- Internal oblique, is the most middle layer of the abdominal wall, its fibres run in a anterior-superior direction.
- The muscle fibres end at the midclavicular line
- Sheet of muscle becomes aponeurotic and insets on the linea alba
describe transverses abdominis
- Transversus abdominis deep layer of the abdominal wall
- Fibres run in a transverse direction
- Ends at midclavicular line
- Sheet becomes apenurotic inserts on linea alba
what are the attachments of the rectus abdomens
- Rectus abdominis is a large muscle running from the xiphoid process superiorly to the pubic symphysis inferiorly.
- it protects the trunk
describe the structure of the rectus abdominis
- The muscle has tendionous intersections along the length of the muscle.
- There are tendinous intersections as the muscle fibres are split up into smaller portions
- Llinea alba is in between these
what is the rectus abdominis enclosed by
- the aponeurotic sheath which is derived from the aponeuroses of external oblique, internal oblique and transversus abdominis, this forms the rectus sheath
describe the layers of the rectus sheath above the arcuate line
- External oblique is anterior to rectus abdominis
- Internal oblique half runs anterior half runs posterior
- Transverse abdominis runs posterior to the rectus abdominis
- transversals fascia is posterior to the rectus abdominis
describe the layers of the rectus sheath below the arcuate line
- All run anterior to the rectus sheath, (transverse abdominis, internal oblique and external oblique), transversalis fascia runs behind the rectus sheath
what is transversals fascia
- it is a sheath that is behind transverse abdominis
describe the blood supply to the anterior abdominal wall
- Internal thoracic artery continuous into the abdomen when it becomes the superior epigastric artery – supplies superior portion of the rectus abdominis
- Inferior epigastric artery supplies inferior portion of rectus abdominis, it is a branch of the external lilac artery, it runs along the deep surface of the abdominal wall
- Lowe intercostal arteries from T11-T12 wrap around and supply the abdominal wall
- Lumbar arteries supply it as well
describe the nerve supply of the anterior abdominal wall
• T7 = xiphoid • T10 = umbillicus T12 • subcostal nerve L1 • Iliohypogastric nerve • Ilioinguinal nerve
what is the final intercostal nerve
T11
what is T12 known as
Subcostal nerve as it runs below the ribs, runs beneath the 12th rib
what 2 nerves does L1 split into
- Iliohypogastric nerve
- Ilioinguinal nerve
where does the gentiofemroal nerve emerge from
L1 and L2
- it pierces through posas major and then splits into two branches - a genital branch and a femoral branch
what is the inguinal ligament
Inguinal ligament is a free inferior border of the external oblique muscle
what forms the inguinal ligament
apernosis is connecting to ASIS and pubic tubercle which forms the inguinal ligament, from the external oblique muscle
what passes underneath the inguinal ligament
NAV
- femoral nerve
- femoral artery
- femoral vein
what are the main structures that pass through the inguinal canal
– spermatic cord,
- rough ligament of the uterus