The abdominal Wall Flashcards
what is the Linea Semilunaris?
where does it get it’s name from?
its the tendinious intersection between the oblique muscle (lateral) and the rectus abdominalis (medial)
-it looks like a half moon
what is the Linea Alba?
what is it also known as?
fibrous connective tissue representing the fusion of 3 aponeuroses
“the white line”
what are the transverse intersections created by?
tendons
how is the rectus sheath organized from superficial to deep?
-skin
-camper’s fascia
Scarpa’s fascia
-anterolateral muscles of the abdominal wall
-transversalis fascia
-peritoneum
what is the superficial fascia composed of a fatty layer?
camper’s fascia
what are the muscles of the anterior abdominal wall?
- Rectus Abdominis
- external oblique
- internal oblique
- transversus abdominis
how is the muscle fiber of the external oblique muscle oriented?
anterior/inferior
how is the muscle fiber of the internal oblique muscle oriented?
anterior/superior
transitions slightly as we move away from truck (distally)
how is the muscle fiber of the transversus abdominis muscle oriented?
horizontal/transverse
what is an aponeurosis?
its a flat, broad tendon for muscular attachment
how is the muscle fiber of the rectus abdominis muscle oriented?
vertical
Rectus abdominis
Origin
Insertion
actions?
Origin: pubic crest/ superior public ramus
Insertion: Costal cartilage rib 5-7, xiphoid process
actions: compression of abdominal contents, flexion of the vertebral colulmn
External Oblique
Origin
Insertion
actions?
Origin: Ribs
Insertion: linea alba, anterior hip bone (pelvis)
actions: compresses abdominal contents
bilateral lumbar flexion
unilateral: contralateral rotation of the trunk and ipsilateral lateral flexion
when contracting external oblique from pelvis to rib what action is accomplished?
ipsilateral lateral flexion
when contracting external oblique from ribs to pelvis what action is accomplished?
-contralateral rotation of the trunk
internal Oblique
Origin
Insertion
actions?
Origin: thoraclumbar fascia, anterior hip bone
Insertion: Ribs 10-12 and linea alba
actions? compresses abdominal content
bilateral: lumbar flexion
unilateral: ipsilater truck rotation and lateral flexion
how does the rotational movement differ between the internal and external oblique?
think ob a bicycle crunch, the external oblique will undergo a contralateral rotation where as the internal oblique will undergo an ipsilateral rotation of the trunk
transversus abdominis
Origin
Insertion
actions?
Origin:: ribs 7-12, thoracolumbar fascia, anterior hip bone
Insertion: linea alba, public tubercule
actions? compresses abdominal content
what do the oblique muscles and tranversus abdominis transition into? what do they invest around? on what do they insert?
transition into aponeuroses along the midline.
invest around rectus abdominis and insets onto linea aspera
how is the linea alba formed?
aponeuroses of the obliques joint at the midline
what forms the linea semilunaris?
the start of aponeuroses on the lateral sides of the rectus abdominis muscle
what muscles play a role in respiration?
obliques (internal and external) as well as the rectus abdominis
how is the rectus sheath organized when above the arcuate line?
- anterior to rectus muscles: aponeuroses of external obliques and half of internal oblique
- posterior to rectus muscles: aponeuroses of the later half of internal obliques and transversus abdominis
how is the rectus sheath organized when below the arcuate line?
all three aponeuroses (external, internal and transversus abdominalis) all lie anterior to the rectus muscle
what nerves are responsible for the motor and sensory innervation of the anterior abdominal wall?
Thoracoabdominal Nerves (T7-T11) subcostal nerve T12
when executing a crunch what contraction of the rectus abdominis is being executed?
contraction of ribs to pelvis
when executing a reverse crunch what contraction of the rectus abdominis is being executed?
contraction of the pelvis to the ribs
where does the superior epigastric artery arise from?
it arises from the internal thoracic artery and descends along the posterior (inner) surface of the rectus abdominis muscle
where does the inferior epigastric artery arise from?
it arises from the external iliac artery and ascends along the posterior (inner) surface of the rectus abdominis muscle.
what artery supplies the lower extremities with blood?
the iliac artery
what muscles compose the posterior abdominal wall?
- quadratus lumborum
- Psoas Major
- psoas Minor
- Illiacus
which muscles of the posterior abdominal wall stretches between rib XII and TP of the lumbar vertebrae to iliac crest?
quadratus lumborum
which muscle groups assist in lumbar function, but mainly functions for the lower limbs?
Psoas Minor, Major and Iliacus
what type of movement can be executed by the quadratus lumborum?
bilateral: assists in flexion of the spine
unilateral: ipsilateral lateral flexion
what muscle contributes to the posterolateral walls of the abdomen?
Transversus Abdominis
what is an important characteristic of the diaphragm?
it contributes to the posterior abdominal wall
what are the 3 openings found in the diaphargm, where are they located and what structures do they allow to pass through?
Caval Hiatus allows for the Inferior Vena Cava to pass through at around TVIII
the Esophageal Hiatus allows the esophasus to pas through at TX
the Aortic Hiatus allows for the aorta to pass through around TXII
what are the crura?
what is their function?
its a tendinous extension of the diaphragm
it anchors the diaphragm to the vertebral column below (muscular tethering system)
what is particular about the right crus?
- longer than left
- its fibers cross the bottom hiatus creatingh a sphincter for the esophagus.
which ligament is responsible for anchoring the diaphragm at the superior border to quadratus Lumborum muscle?
lateral arcuate ligament
which ligament is responsible for anchoring the diaphragm at superior boerder of psoas major muscle?
Medial Arcuate ligament
what connects the left and right crus?
the median arcuate ligament
which ligament forms the aortic hiatus?
the median arcuate ligament
