Week 6: Abdominal Muscles, Fascia and Ligaments Flashcards
Structure: External Oblique
Innervation: Ventral primary rami of T7 to T12.
Primary action: compresses and supports abdominal viscera.
Flexes and rotates trunk
fibers run inferomedially (toward belly button)
structure: Internal oblique and fascia
innervation: Ventral primary rami of T7 to T12; conjoined tendon supplied by L1.
Primary action: compresses and supports abdominal fascia, lateral flexion, ipsilateral trunk rotation
Fibers run superomedially (up and toward the sternum, perpendicular to external oblique fibers)
structure: Transverse abdominis
innervation: ventral primary rami of T7 to T12; conjoined tendon is supplied by the ilioinguinal nerve (L1).
primary action: Flexes trunk, compresses abdominal viscera, stabilizes and controls tilt of pelvis (antilordosis)
Fibers run transversely except inferior portion, which run parallel to internal oblique fibers
Structure: Rectus abdominis mm.
Innervation: Ventral primary rami of T7 to T12.
Primary action: flexion of thoracic and lumbar spine, assists forces expiration
structure: psoas major
innervation: Lumbar plexus L2, 3, and 4
primary action: flexion of the thigh at the hip
Proximal attachment
The anterior surfaces and lower borders of the transverse processes of all the lumbar vertebrae, by five digitations, each from the sides of the bodies of the last thoracic vertebra and all lumbar vertebrae and the interposed intervertebral discs.
Distal attachment
The lesser trochanter of the femur after being joined by the tendon of iliacus.
structure: iliacus mm.
innervation: femoral n. L2, L3
Primary action: flexion of thigh at the hip
Proximal attachment
Superior two-thirds of the internal surface of the iliac fossa, the inner lip of the iliac crest, the ventral surface of the sacroiliac and iliolumbar ligaments, and the upper surface of the lateral part of the sacrum.
Distal attachment
The lesser trochanter of the femur after being joined by the tendon of psoas major. The conjoined tendon passes under the inguinal ligament to enter the thigh.
structure: quadratus lumborum
innervation: ventral primary rami T12-L3
Primary action: lateral flexion of lumbar spine, elevation of the pelvis, stabilizes 12th rib during inspiration.
Proximal attachment
Transverse processes of L1 to L4, the iliolumbar ligament, and the posterior third of the iliac crest.
Distal attachment
Inferior border of the 12th rib.
structure: Inguinal ligament
innervation: N/A
Primary action: Provides a ‘bridge’ under which the vessels traveling in or out of the pelvis may pass.
Proximal attachment
The anterosuperior aspect of the iliac spine.
Distal attachment
The pubic tubercle.
structure: Parietal peritoneum
innervation: somatic n., intercostal n., and phrenic n.
Primary action: The peritoneum is essentially a single membranous sheet that lines the abdominal and pelvic cavities.
Structure: greater omentum, a double layered sheet of visceral peritoneum folded over to form four layers
Primary action: helps ward off inflammation, rich blood supply and lymphatics, fat storage (insulation). Can become extremely fatty in mordibly obese individuals
Structure: lesser omentum
Lesser is a thin double fold of peritoneum that extends from lesser curvature of the stomach to the porta hepatis of the liver.
Primary action: supports stomach and prevents spread of infection
Describe the difference between parietal and visceral peritoneum.
Parietal~wall
parietal peritoneum lines the body wall, is sensitive to pressure, pain, heat , cold, lacerations, and pain is localized. e.g., a punch to the gut is felt at the site of the punch.
viscera~organs
Visceral peritoneum lines the intraperitoneal organs, for example the kidneys are covered by the adipose capsule, and the liver is covered by visceral peritoneum.
