Anterior Abdominal Wall Flashcards
What is the superior and inferior boundary of the abdomen?
Superior - diaphragm/4th intercostal space
Inferior - pelvic girdle
What are the two horizontal planes and two vertical planes that divide the abdomen into 9 regions?
Horizontal - transpyloric and interspinous
Vertical - midclavicular lines
Where is the transpyloric plane located?
Tip of the 9th rib and projects back onto L1
What does the subcostal plane project back onto?
L3
Supracrystal plane projects posteriorly to where?
L4
Where does the transtubercular plane project posteriorly to?
L5
What are the layers of the abdominal wall?
Skin Camper’s fascia Scarpa’s fascia External oblique m Internal oblique m Transverus abdominus m Transversalis fascia Extraperitoneal fat Parietal peritoneum
As the scarpas fascia reaches the region of the scrotum, what does it become?
Dartos fascia
As the dartos fascia reaches the peritoneal region, what does it become?
Collies fascia
What is the first layer of muscle? Which direction do the fibers run?
External oblique m, inferomedially
What is the second layer of muscle? Which direction do the fibers run?
Internal oblique, superomedially
What is the third layer of muscles? Which direction do the fibers run?
Transversus abdominus, horizontally
What is the anterior most layer of muscles?
Rectus abdominus
What does the external oblique aponeurosis form?
Inguinal ligament and linea alba
What does the internal oblique aponeurosis become?
Linea alba
What does the pyramidalis do?
Pulls on the linea alba; absent in many people
What are the general functions of the abdominal muscles?
Inhalation, expiration, flexion, rotation, compression, sidebending, creating internal abdominal pressure
What forms the posterior and anterior rectus sheath?
The three muscle layers
What is the arcuate line?
The transition where the organization of the rectus sheath changes
Below the arcuate line, how is the rectus sheath organized?
Anterior: external and internal oblique and transversus abdominus
Posterior: transversalis fascia
Above the arcuate line, how is the rectus sheath organized?
Anterior: external and internal oblique
Posterior: internal oblique, transversus abdominus, transversalis fascia
Where is the arcuate line located?
A third of the way between the umbilicus and pubic tubercle
Where does the neurovasculature travel between?
The internal oblique and transversus abdominus
What are the spinal nerve roots of the thoracoabdominal nerves?
T7-T11
