4
MuscleTable
Table4-1
MUSCLE
PROXIMAL
ATTACHMENT
(ORIGIN)
DISTAL
ATTACHMENT
(INSERTION)
INNERVATION
MAIN ACTIONS
BLOOD SUPPLY
MUSCLE GROUP
Diaphragm
Xiphoid process,
lower six costal
cartilages,
L1–L3 vertebrae
Converges into
central tendon
Phrenic nerve
Draws central
tendon down
and forward
during
inspiration
Pericardiacophrenic,
musculophrenic,
superior and
inferior phrenic
arteries
Posterior abdominal
wall
External oblique
External surfaces of
ribs 5–12
Linea alba, pubic
tubercle,
anterior half of
iliac crest
Ventral rami of six
inferior thoracic
nerves
Compresses and
supports
abdominal
viscera, flexes
and rotates
trunk
Superior and inferior
epigastric
arteries
Abdominal wall
Iliacus
Superior 2/3 iliac
fossa, ala of
sacrum, anterior
sacro-iliac
ligaments
Lesser trochanter of
femur and shaft
inferior to it, and
to psoas major
tendon
Femoral nerve
Flexes hip and
stabilizes hip
joint; acts with
psoas major
Iliac branches of
iliolumbar artery
Posterior abdominal
wall
Internal oblique
Thoracolumbar
fascia, anterior
2/3 of iliac crest,
lateral half of
inguinal ligament
Inferior borders of
ribs 10–12, linea
alba, pubis via
conjoint tendon
Ventral rami of six
inferior thoracic
and first lumbar
nerves
Compresses and
supports
abdominal
viscera, flexes
and rotates
trunk
Superior and inferior
epigastric and
deep circumflex
iliac arteries
Abdominal wall
Psoas major
Transverse
processes of
lumbar
vertebrae, sides
of bodies of
T12–L5
vertebrae,
intervening
intervertebral
discs
Lesser trochanter of
femur
Ventral rami of first
four lumbar
nerves
Acting superiorly
with iliacus,
flexes hip;
acting inferiorly,
flexes vertebral
column laterally;
used to balance
trunk in sitting
position; acting
inferiorly with
iliacus, flexes
trunk
Lumbar branches of
iliolumbar artery
Posterior abdominal
wall
Psoas minor
Vertebral margins of
T12–L1
vertebrae,
corresponding
intervertebral
disc
Pectineal line,
iliopectineal
eminence
Ventral rami of first
lumbar nerve
Flexes pelvis on
vertebral column
Lumbar branch of
iliolumbar artery
Posterior abdominal
wall
Pyramidalis
Body of pubis,
anterior to
rectus
abdominis
Linea alba
Iliohypogastric nerve
Tenses linea alba
Inferior epigastric
artery
Abdominal wall
Quadratus
lumborum
Medial half of inferior
border of 12th
rib, tips of
lumbar
transverse
processes
Iliolumbar ligament,
internal lip of
iliac crest
Ventral rami of T12
and first four
lumbar nerves
Extends and laterally
flexes vertebral
column, fixes
12th rib during
inspiration
Iliolumbar artery
Posterior abdominal
wall
Rectus abdominis
Pubic symphysis,
pubic crest
Xiphoid process,
costal cartilages
5–7
Ventral rami of six
inferior thoracic
nerves
Flexes trunk,
compresses
abdominal
viscera
Superior and interior
epigastric
arteries
Abdominal wall
Transversus
abdominis
Internal surfaces of
costal cartilages
7–12,
thoracolumbar
fascia, iliac
crest, lateral
third of inguinal
ligament
Linea alba with
aponeurosis of
internal oblique,
pubic crest, and
pecten pubis via
conjoint tendon
Ventral rami of six
inferior thoracic
and first lumbar
nerves
Compresses and
supports
abdominal
viscera
Deep circumflex iliac
and inferior
epigastric
arteries
Abdominal wall
Variations in spinal nerve contributions to the innervation of muscles, their arterial supply, their attachments, and their actions are common themes in human
anatomy. Therefore, expect differences between texts and realize that anatomical variation is normal.
MuscleTable
