COMP 2 Anatomy Muscles Innervations and actions

Quadratus Lumborum Attachments

Iliac Crest, Iliolumbar Ligament, Rib 12, TP L1-L4

Quadratus Lumborum Actions

Extends and laterally flexes vertebral column/trunk, stabilizes 12th rib during inspiration

What innervates the Quadratus lumborum?

Subcostal Nerve, anterior rami of spinal nerve

Quadratus Lumborum Blood supply

Subcostal Artery, Lumbar artery, Iliolumbar artery

Psoas major muscle attachments

VB T12-L5, TP of L1-L5, lesser trochanter of femur

Psoas Major Muscle (Function):

Laterally flexes vertebral column (superiorly) and acts with iliacus to flex thigh

Psoas Major Innervation

anterior rami of L1-L3 spinal nn.

Psoas Major Blood Supply

Iliolumbar artery

Psoas minor attachments

Vertebral Bodies T12-L1, Iliopubic eminence and pecten pubis

“Twelve-Little-Ilio-Pecs”

Breakdown:

• Twelve → T12

• Little → L1

• Ilio → Iliopubic eminence

• Pecs → Pecten pubis

Psoas Minor Functions

Weakly flexes trunk

Psoas Minor Innervation

Ventral ramus of L1 spinal n.

Psoas Minor Blood Supply

Lumbar Artery

Iliacus Attachments

Iliac fossa (sup. 2/3), ala of sacrum, anterior sacroiliac ligament, lesser trochanter of femur

Mnemonic: “I SAT”

• I – Iliac fossa (superior 2/3)

• S – Sacrum (ala of sacrum)

• A – Anterior sacroiliac ligament

• T – Trochanter (lesser trochanter of femur)

Iliacus Functions

Flexes thigh, stabilizes hip joint

Iliacus Innervation

Femoral Nerve

Iliacus blood supply

Medial Circumflex artery, femoral artery, iliolumbar artery

Transversus Abdominis Muscle Attachments

Costal cartilages ribs 7-12, thoracolumbar fascia, iliac crest, iliopectineal arch, linea alba, aponeurosis of internal abdominal oblique muscle, pubic crest, pectineal line of pubis

Transversus Abdominis Muscle Functions

Aids in expiration, ipsilaterally rotates trunk, supports abdominal viscera

Transversus Abdominis Muscle Innervation

- Ventral rami of T7-T11 spinal nn.

- Subcostal n. (T12)

- 1st lumbar n.

Transversus Abdominis Muscle Blood Supply

- Lower posterior intercostal aa.

- Subcostal a.

- Superior epigastric a.

- Inferior epigastric a.

Diaphragm Attachments

Xiphoid Process, costal cartilages ribs 7-12, arcuate ligament, anterior longitudinal ligament, central tendon of diaphragm

Diaphragm Blood Supply

Superior Phrenic Artery

Inferior Phrenic Artery

Pericardiophrenic Artery

Musculophrenic Artery

Subcostal Artery

The major duodenal papilla serves

as the common opening for the common bile duct and main pancreatic duct

Minor duodenal papilla function (do not need to identify 🙂 )

drains the accessory pancreatic duct

Levator ani Attachments

Body of Pubis, tendinous arch, ischial spine, perineal body, coccyx, anococcygeal ligament

Mnemonic: “Aye (I)!!! Pussy Tight, Asshole Clenches Perfectly.”

•  I → Ischial Spine

• P → Pubic bone body

• T → Tendinous arch of obturator internus fascia

• A → Anococcygeal ligament

• C → Coccyx

• P → Perineal body

Levator Ani functions

Supports pelvic viscera and forms most of pelvic diaphragm

Levator Ani Innervation

Pudendal Nerve

- N. to levator ani (S4)

-Inferior rectal n.

- Coccygeal plexus

Levator Ani Blood Supply

- Inferior gluteal a.

- Inferior vesical a.

- Internal pudendal a.

Coccygeus Muscle Attachments

Ischial Spine, Inferior aspect of sacrum and coccyx

Coccygeus Muscle Functions:

Flexes coccyx and supports pelvic viscera

Coccygeus Muscle Innervation

- N. to levator ani (S4)

- Inferior rectal n.

- Coccygeal plexus

Coccygeus Muscle Blood Supply

- Inferior gluteal a.

- Inferior vesical a.

- Internal pudendal a.

Obturator Internus Attachments:

Obturator membrane, obturator foramen, greater trochanter of femur

Obturator Internus Functions

Externally rotates extended thigh and abducts flexed thigh

Obturator Internus Innervation

N. to obturator internus

Obturator Internus Blood Supply

Obturator Artery and internal Pudendal Artery