Gross 2 Posterior Abdominal Wall Flashcards
What are the attachments of the Diaphragm?
Inferior margin of thoracic cage
First 3 Lumbar Vertebrae
What are the Apertures in the Superior Boundary?
What level are they in and what goes through them? (4)
- Caval Opening: T8 level, opening for IVC
- Esophageal Hiatus: T10 level, opening for terminal end of esophagus
- Aortic Hiatus: T12 level, opening for abdominal portion of aorta
- Sternocostal Triangle: Opening for Superior Epigastric Vessels
What is the Medial Arcuate Ligament? What is it a passage for?
A thickening of the Psoas Fascia at the diaphragm
- Its a passage for sympathetic trunks and Least Splanchnic nerves
What is the Lateral Arcuate Ligament?
A thickening of the quadratus fascia at the diaphragm
Why are the Apertures of the Curs of the Diaphragm important?
They are a passage for the Greater and Lesser Splanchnic Nerves
What are the Fascias of the Posterior Abdominal Wall?
- Transversalis Fascia (Endoabdominal Fascia)
- Psoas Fascia
- Thoracolumbar Fascia:
–Anterior Layer
–Middle Layer
–Posterior Layer
What are the muscles of the Posterior Abdominal Wall?
- Psoas Major
- Iliacus
- Quadratus Lumborum (QL)
How does the Psoas Major run? (Pathway)
How will the Lumbar Plexus course with the Psoas?
- Runs inferior-lateral
- Passes deep to the Inguinal Ligament
- Lumbar Plexus is embedded with the Psoas
- Nerves of the lumbar plexus will course medial, lateral of through the psoas major/
How does the Iliacus run? (Pathway)
- Its in the abdomen, The anterior surface/fascia is separated from the extraperitoneal tissue and peritoneum
- The fibers then join the lateral side of the Psoas
Is the QL a muscle of the back or the abdomen?
Yes,
- Anteriorly the QL is covered by the anterior layer of the Thoracolumbar Fascia
- The QL lays posterior to the colon, kidney, and Psoas
What is the Unilateral function of the QL?
- Stabilizes the pelvis during walking
–There is a burst of QL activity at heel strike in EMG studies
–Works synergistically with opposite Glute Med. - Ipsilateral flexion of the vertebral column
- Stabilizes the spine when carrying loads on the contralateral UE
What are the Bilateral functions of the QL?
The QL extends the spine
What are the Respiratory functions of the QL?
Stabilizes the 12 ribs to assist with efficiency of inspiration (Helps depress the rib)
What nerve roots make up the Lumbar Plexus?
Ventral Rami L1 - L4
What regions are innervated by the Lumbar Plexus?
Structures of the abdominal walls, pelvic regions, and lower extremities
Where are the divisions found in the Lumbar Plexus?
L2 - L4
What terminal nerves arise from the Anterior Divisions of the Lumbar Plexus?
- Obturator N. (L2-L4)
- Genitofemoral N. (L1 and L2 ant.)
- Lumbosacral Trunk (L4 ant. and L5)
What terminal nerves arise from the Posterior Divisions of the Lumbar Plexus?
- Lateral Femoral Cutaneous N. (L2-L3)
- Femoral N. (L2-L4)
- Accessory Obturator N. (L3-L4)
What are the functions of Iliohypogastric N?
Sensory:
- Lateral Gluteal Region
- Upper Inguinal Region
- Hypogastric/Pubic region of the abdominal wall
Motor:
- Internal/External Abdominal Oblique
- Transverse Abdominis
What are the functions of the Ilioinguinal N.?
Sensory:
- Pubic Symphysis
- Inguinal Region
- Anterior Scrotum
- Anterior Labia Majora
Motor:
- Internal Abdominal Oblique
- Transverse Abdominis
What are the functions of the Genitofemoral N.?
Sensory:
- Femoral Triangle (Femoral Branch)
- Anterior Scrotum (Genital Branch)
- Anterior Labia Majora (Genital Branch)
What are the Classifications of branches/planes of the Abdominal Aorta?
- Anterior Midline
- Lateral
- Posterior lateral
What are the arteries of the Posterior Abdominal Wall and what do they supply?
- Inferior Phrenic A.: supplies the Inferior Surface of the diaphragm
- Subcostal A.: Supplies the muscle and skin along the lateral wall
- Lumbar A.: Supplies the posterior wall, including the vertebral column
What are the arteries of the Anterior Midline?
For Digestive Tract
- Celiac Trunk
- Superior Mesenteric
- Inferior Mesenteric