Abdominal Wall Flashcards
Describe the layers of the abdominal wall
superficial to deep:
* skin
* superficial fatty layer of subcutaneous tissue (Camper fascia)
* deep mbranous layer of subcutaneous tissue (Scarpa fasia)
* superficial fascia
* external oblique
* intermediate fascia
* internal oblique
* deep fascia
* transverse abdominis
* endoabdominal (transversalis) fascia
* extraperitoneal fat
* parietal peritoneum
between each layer of muscle, there is the superficial, intermediate, and deep investing fascia
Describe the position of the abdominal muscles that enclose the abdominal cavity
- antero-medially: rectus abdominis
- postero-laterally: quadratus lumborum
- laterally: external oblique, internal oblique, transverse abdominis
What is Scarpa’s fascia fused with?
linea alba:
band of connective tissue that runs from a person’s sternum to their pubic bone
and
deep fascia of the thigh near the inguinal ligament
Discuss the borders of the abdominal wall
superiorly: xiphoid process, costal margins, diaphragm
inferiorly: pelvic bones, inguinal ligament
posteriorly: lumbar vertebrae
The flat muscles of the anterolateral abdominal wall will attach ____ to an aponeurosis
medially
What do the aponeuroses of external oblique, internal oblique, and transverse abdominis form?
rectus sheath which contains rectus abdominis and pyramidalis muscle
What is the arcuate line and its importance?
halfway between umbilicus and pubic crest
* arrangement of rectus sheath changes at this line
rostral to the arcuate line:
* superficial to deep: skin, campers fascia, scarpa’s fascia, external obliques, internal obliques, transverse abdominis
* muscle has its own fascia which thickens medially to form aponeurosis and rectus sheath for rectus abdominius
* fascia of external oblique travels anterior to rectus abdominis
* fascia of internal oblique splits to envelop rectus abdominis
* fascia of transverse abdominis travels posterior to rectus abdominis
caudal to the the arcuate line:
* all three fascia travel anterior to rectus abdominis
* continuous with fascia of rectus abdominis which is deep to the 3 fascia
inguinal ligament
* where is it
* what is its function
- anterior superior iliac spine to pubic tubercle
- attachment point for muscle
- acts as a retinaculum that pins down the femoral nerve, artery, and vein as it psses from the pelvic cavity to thigh
- forms floor of the inguinal canal
inguinal canal
What is its importance
site of vulnerability for inguinal hernia
the pathway by which the testes leave the abdominal cavity and enter the scrotum
inguinal hernia
where a loop of the small intestine can strangulate the spermatic cord?
Describe dorsal and ventral ramus branching in the abdominal region
dorsal and ventral ramus
ventral ramus travels anteirorly and branches into sensory nerve that innervates a dermatome and a motor nerve that innervates a closely associated myotome.
dorsal ramus supplies the epimere and skin covering it
ventral ramus supplies the hypomere and the skin covering it
Epimere: dorsal part of the myotome that develops into the muscles of the back, including the erector muscles of the spine, intertransversals, and interspinals
Hypomere: The ventral part of the myotome that develops into the muscles of the thorax and abdomen, as well as the muscles and fascia that move the limbs
What segmental levels can you find the thoraco-abdominal nerves
T7-T11
What segmental level can you find the following
* lateral and anterior cutaneous branch of subcostal nerve
* iliohypogastric nerve
* ilio-inguinal nerve
- T12
- L1
- L1
How can you remember the fibre direction for exeternal abdominal obliques?
same direction as finger tips when you put your hand in your pockets
Superiorly to inferiorly from lateral to medial
Describe the fibre direction for external and internal obliques
- external obliques: start rostro-laterally and continue caudal-medially
- internal: originate caudal-lateral and insert rostro-medially
