10/6: Anterolateral Abdominal Wall Flashcards
Name the abdominal wall layers from superficial to deep
Skin
Camper’s Fascia (fatty SF)
Scarpa’s fascia (membranous SF)
3 layers of muscle
Transversalis fascia
Extra peritoneal fat
Parietal peritoneum
Abdominal organs
What is the skin?
Outermost layer
What fat is stored in the Camper’s fascia (fatty SF)?
subcutaneous fat is stored
varies in thickness
What nerves and vessels run in camper’s fascia to get to skin?
Cutaneous nerves and vessels
has neurovasculature
Scarpa’s fascia (membraneous SF)
Thin, loosely arranged CT w/ vessels and veins
No fat
What does the scarpia’s fascia tightly arrange to form?
Fibers tightly arrange to form membrane
Where is the scarpa’s fascia only found in?
Anteriorly
What do the 3 layers of muscle have the same organization as (broad flat sheets)
intercostals
What are the 3 layers of muscle?
External oblique, internal oblique, and transversus abdominus
transversalis fascia
CT layers that line whole anterior and lateral abdominal wall
Extraperitoneal fat
Similar to body fat in composition; varies in thickness (outside of peritoneum)
What does the parietal peritoneum secrete?
Fluid to provide lubricant forming frictionless movement
Whatis the parietal peritoneum?
lining of body
What are the group functions of the abdominal wall muscles?
Movement of the trunk
What are the bilateral and unilateral functions of the trunk?
Bilateral: pure flexion
unilateral: lateral flexion and rotations/twisting
What are the insertions of the rectus abdominis?
4 tendinous insertions into the superficial division of the rectus sheath
Where is the insertion of the rectus abdominis?
Costal cartilages and xiphoid processes of sternum
How do the fibers of the rectus abdominis run?
Vertically
about 3 times as wide superiorly as inferiorly
Where is the origin of the rectus abdominis?
pubis
What gives six pack appearance?
Rectus abdominus due to 4 tendenous insertions into the superfiical division of the rectus sheath
Where do external oblique fibers run?
Down and in towards midline (same as external intercostals)
Where does the inguinal ligament run?
From anterior superior iliac spine to public spine
Where does the external oblique attach from?
Ribs and costal cartilages laterally to iliac crest and anterior superior iliac spine
What is the aponeurosis
Abrupt transition from muscle fibers to ligamentum at location of anterior superior iliac spine
Where does aponeurosis insert on?
Linea alba and pubic bone on opposite side
Where does the internal oblique attach from?
Iliac spine and deep inguinal ligament to linea alba (where the aponeuroses come together)
What muscle fibers are fan shaped?
Internal oblique
What is the innermost layer of abs?
Transversus abdominis
Where does transversus abdominis attach from?
Lateral edge of transversalis fascia, iliac crest and internal oblique fascia to linea alba
What does the internal oblique have?
Fibers that originate from the deep surface of the inguinal ligament
What does the internal oblique give rise to?
lower fibers of transversus abdominis
What does the abdominal wall gap located?
Between inguinal ligament and pelvis
What does the abdominal wall gap function to allow?
Neurovascular structures (femoral artery, vein, and nerve) and iliopsoas to enter and be distributed into the lower limb
Above the arcuate line in the top 3/4th’s of the rectus sheath, where do the EAO aponeuroses pass?
Superficial to the rectus abdominus and ends at linea alba
Above the arcuate line in the top 3/4th’s of the rectus sheath, what do the IAO aponeuroses split into?
Two thinner layers (one superficial that fuses with EAO to form superficial half of rectus sheath) (other later fuses with
TA aponeuroses to from deep half of rectus sheath)
Above the arcuate line in the top 3/4th’s of the rectus sheath, where do the TA aponeuroses pass?
deep to rectus abdominis and ends at linea alba
What is the pathway of aponeuroses in the bottom 1/4ths below the arcuate line?
EAO, IAO, and TA all pass superficially to the rectus abdominis and fuse together to form a superficial rectus sheath
What does the abdominal wall gap allow for communication?
Between body cavity and lower limb
What is sensory innervation of the skin over the anterior abdominal wall provided by?
Ventral rami
lower 5 intercostal nerves (T7-11)
Subcostal nerve (T12)
Iliohypogastric/ilioinguinal nerves (L1)
What nerves provide somatic motor innervation to the anterior abdominal wall muscles?
Same ones as for the anterior
lower 5 intercostal nerves (T7-11)
Subcostal nerve (T12)
Iliohypogastric/ilioinguinal nerves (L1)
Where do arteries run?
In the rectus sheath deep to the muscle
Where does lymph from skin above the umbilicus (including the back and upper limb) drain to?
Axillary nodes
Where does lymph from skin below the umbilicus (including the back, pelvis, perineum, and lower limb) drain to?
Superficial inguinal nodes
What is the main function of the abdominal wall?
Movement of the trunk
What are less obvious functions of the abdominal wall muscles?
- Stabilizaiton of the trunk during strenuous physical effort (Valsalva’s maneuver)
- Forceful expiration
- Coughing and sneezing
- urination and defecation
- labor deliver
What are the functions of the trunk?
Flexion (pure)
Lateral flexion
Rotation (twisting)
How do the abdominal wall muscles affect the abdominal cavity?
- Decrease abdominal cavity volume/increase intraabdominal pressure
- Abdominal organs increase pressure in thorax and pelvis
