Unit 4 Second Order

Where is the external oblique located?

Superficial lateral abdominal wall

What is the origin of the external oblique?

Ribs

What is the insertion of the external oblique?

Linea alba and os coxae

What is the action of the external oblique?

Compress and support abdominal viscera, flex, and rotate trunk

What is the innervation of the external oblique?

Thoraco-abdominal and subcostal nerves

What is the blood supply of the external oblique?

Lower intercostal, subcostal, deep circumflex iliac arteries

Where is the internal oblique located?

Deep to external oblique

What is the origin of the internal oblique?

Thoracolumbar fascia, iliac crest, inguinal ligament

What is the insertion of the internal oblique?

Ribs, linea alba, os coxae

What is the action of the internal oblique?

Compress and support abdominal viscera, flex and rotate trunk

What innervates the internal oblique?

Thoraco-abdominal nerves, subcostal and first lumbar nerves

What is the blood supply of the internal oblique?

Lower posterior intercostal, subcostal, deep circumflex iliac arteries

Where is the transversus abdominis located?

Deepest flat abdominal muscle

What is the origin of the transversus abdominis?

Costal cartilages of lower ribs, thoracolumbar fascia

What is the insertion of the transversus abdominis?

Linea alba and os coxae

What is the action of the transversus abdominis?

Compress and support abdominal viscera

What innervates the transversus abdominis?

Thoraco-abdominal nerves, subcostal and first lumbar nerves

What is the blood supply of the transversus abdominis?

Lower posterior intercostal, subcostal, deep circumflex iliac arteries

Where is the rectus abdominis located?

Anterior vertical abdominal wall

What is the origin of the rectus abdominis?

Pubic symphysis and os coxae

What is the insertion of the rectus abdominis?

Xiphoid process, costal cartilages of ribs

What is the action of the rectus abdominis?

Flex trunk, compress abdominal contents, stabilize pelvis

What innervates the rectus abdominis?

Thoraco-abdominal nerves and subcostal nerves

What is the blood supply of the rectus abdominis?

Superior and inferior epigastric arteries

Where is the pyramidalis located?

Anterior to lower rectus abdominis

What is the origin of the pyramidalis?

Os coxae

What is the insertion of the pyramidalis?

Linea alba

What is the action of the pyramidalis?

Tense linea alba

What innervates the pyramidalis?

Subcostal nerve

What is the blood supply of the pyramidalis?

Inferior epigastric artery

Where is the quadratus lumborum located?

Posterior abdominal wall

What is the origin of the quadratus lumborum?

Os coxae

What is the insertion of the quadratus lumborum?

12th rib and lumbar vertebrae

What is the action of the quadratus lumborum?

Extend and laterally flex vertebral column

What innervates the quadratus lumborum?

T12–L4 anterior rami

What is the blood supply of the quadratus lumborum?

Lumbar, iliolumbar arteries

Where is the iliacus located?

Iliac fossa

What is the origin of the iliacus?

Sacrum

What is the insertion of the iliacus?

Femur via iliopsoas tendon

What is the action of the iliacus?

Flex thigh and stabilize hip

What innervates the iliacus?

Femoral nerve (L2–L4)

What is the blood supply of the iliacus?

Iliac branches of iliolumbar artery

Where is the psoas major located?

Lateral to lumbar vertebrae

What is the origin of the psoas major?

T12–L5 vertebrae

What is the insertion of the psoas major?

Femur

What is the action of the psoas major?

Flex thigh, stabilize hip, trunk flexion when sitting

What innervates the psoas major?

Anterior rami of L1–L3

What is the blood supply of the psoas major?

Lumbar branches of iliolumbar artery

Where is the psoas minor located?

Anterior to psoas major (inconsistent)

What is the origin of the psoas minor?

T12 and L1

What is the insertion of the psoas minor?

Os coxae

What is the action of the psoas minor?

Weak trunk flexion

What innervates the psoas minor?

Anterior ramus of L1

What supplies blood to the psoas minor?

Lumbar arteries

Where is the levator ani located?

Pelvic diaphragm

What is the origin of the levator ani?

Os coxae and tendinous arch

What is the insertion of the levator ani?

Walls of prostate, vagina, rectum, and anal canal

What is the action of the levator ani?

Support pelvic viscera, maintain continence

What innervates the levator ani?

Pudendal nerve

What supplies blood to the levator ani?

Inferior gluteal artery, internal pudendal artery

Where is the coccygeus located?

Posterior pelvic floor

What is the origin of the coccygeus?

Os coxae

What is the insertion of the coccygeus?

Inferior sacrum and coccyx

What is the action of the coccygeus?

Support pelvic viscera, coccygeal flexion

What innervates the coccygeus?

S4, S5

What supplies blood to the coccygeus?

Inferior gluteal artery