The Back Flashcards
1st Layer
Trapezius
Latissimus Dorsi
Ventral Primary Rami
False muscles –> produce and control limb movements
2nd Layer
Levator Scapulae
Rhomboid Minor
Rhomboid Major
Ventral Primary Rami
False Muscles
Intermediate Extrinsic Back Muscles
3rd Layer
Serratus Posterior Superior: intercostal nn 2-5
Serratus Posterior Inferior: Ventral rami of nn T9-12
Active in respiration
True Back Muscles
3 layers
- Splenius
- Erector Spinae
- Transverospinalis
Only move axial skeleton, act to maintain posture and control movements of vertebral column
Dorsal Primary Rami
Erector Spinae
Inside: Spinalis
Middle: Longissimus
Outisde: Iliocostalis
Iliocostalis
3 parts
tie sacrum and hip to ribs and cervical vertebrae
extend and laterally flex vertebral column
Longissimus
3 parts
tie transverse processes of vetebrae, ribs, and sacrum
longissimus capitus extends and rotates head
extend and laterally flex vertebral column; thoracic part rotates ribs for forceful inspiration
Spinalis
2 parts
tie spinous processes of vertebrae from L2-C2
Extend vertebral column
Splenius
Dorsal Rami
Splenius: capitis and cervicis
Medial to lateral orientation
Capitis origin: ligamentum nuchae; insertion: mastoid process
Bilateral action: extension of the head
Unilateral action: head and neck rotation to ipsilateral side
Deep Layer of Intrinsic Back Muslces
Transversospinalis
1) Semispinalis “superficial”
2) multifidus “middle”
3) rotatores “rotator muscles”
Semispinalis
3 parts
tie transverse processes of vertebrae from C2-T10 and nuchal lines of occipital bone
extend vertebral column and head
Semispinalis capitis covers cervicis; cpaitis inserts between superior and inferior nuchal lines; head, neck extension
Multifidus
small muscles that tie transverse processes of one vertebrae to spinous processes of vertebrae superior to it
extend and rotate vertebral column
Rotatores
small muscles that tie transverse processes to spinous processes of adjacent vertebrae
extend and rotate vertebral column - rotation is to opposite side
