muscles of the back Flashcards
3 groups of muscles in the back
superficial
intermediate
deep back muscles
extrinsic muscles function
superficial back muscles - produce/control shoulder movements
trapezius
latissimus dorsi
levator scapulae
rhomboids
latissimus dorsi is a muscle of the ____ extremity
upper (even though it is kind of lower)
action of lats
extends, adducts, and medially rotates humerus
innervation of latissimus dorsi
thoracodorsal nerve - ventral rami c6, c7, c8
action of traps
elevates, rotates, and retracts scapula (shrug shoulders)
innervation of trapezius
receives its motor innervation via the 11th CN - spinal accessory nerve
intermediate muscles of the back
small muscles that aid and assist in respiratory control
- serrates posterior superior (deep to rhomboids)
- serrates posterior inferior (deep to latissimus)
deep back muscles are referred to as ______ back muscles because these muscles all act specifically on moving and or stabilizing the vertebral column
true/intrinsic
paraspinal muscles
deep back muscles because of their position alongside the side of the spinal column
layers of the deep muscles of the back
superficial intrinsic layer - splenius muscles (cervical region)
intermediate intrinsic layer - erector spinae mm complex
deepest intrinsic layer - transversospinalis (deep to spinae)
all deep/intrinsic muscles of the back are innervated by _____ of spinal nerves
dorsal rami
only deep muscles (d for deep)
erector spinae complex
intermediate layer of intrinsic/deep back muscles
divided into 3 mm masses
iliocostalis
longissimus
spinalis
action of erector spinae complex
postural muscles, help extend and stabilize column
transversospinalis mm complex
course from transverse process to spinous process
