Muscles Flashcards
Latissimus Dorsi
O: SPs of T6-12, Thoracolumbar fascia, Iliac Crest, inferior 3 or 4 ribs
I: Floor of Intertubercular (or Bicipital) Groove (sulcus) of the Humerus
A: Extension, ADD, MR of humerus. Downward rotation of the Scapula. Raises body towards arms when climbing
N: Thoracodorsal n. (C6, C7, C8)
B: Thoracodorsal a.
Levator Scapulae
O: Posterior tubercles of TPs C1-4
I: Medial border of scapula, superior to root of scapular spine A: Elevation and downward rotation of scapula; bilaterally, extension of neck N: Dorsal scapular n. (C5) B: Dorsal scapula a.
Rhomboid Major
O: SPs T2-5
I: Medial border of scapula from level of spine to inferior angle
A: Retraction and downward rotation of scapula; fix scapula to thoracic wall
N: Dorsal scapular n. (C4, C5)
B: Dorsal scapular a.
Rhomboid Minor
O: Nuchal l. and SPs of C7 and T1
I: Smooth triangular area at base of scapular spine
A: Retraction and downward rotation of scapula; fix scapula to thoracic wall
N: Dorsal scapular n. (C4, C5)
B: Dorsal scapular a.
Serratus Posterior Superior
O: Nuchal l., SPs C7-T3
I: Superior borders of 2nd to 4th ribs
A: Proprioception (elevation of ribs); considered accessory m. of respiration
N: Ventral Rami 2nd-5th Thoracic Spinal nn.
Serratus Posterior Inferior
O: SPs T11-L2
I: Inferior borders of 8th-12th ribs near their angles
A: Proprioception (depress ribs); considered accessory m. of respiration
N: Ventral Rami T9-T12 Thoracic Spinal nn.
Splenius Cervicis
O: SPs of T3-T6
I: Tubercles of TPs C1-C3 A: Ipsilateral: rotation and lateral flexion; Bilateral: extension of neck
N: Dorsal rami of spinal nn.
Splenius Capitis
O: Nuchal l. and SPs of C7-T3
I: Mastoid process and lateral 1/3 of superior nuchal line
A: Ipsilateral: rotation and lateral flexion; Bilateral: extension of head
N: Dorsal rami of spinal nn.
Iliocostalis Forms the lateral column
O: Posterior iliac crest, sacrum, sacral and inferior lumbar SPs and sacrospinous & supraspinous l.
A: Bilateral - extension of vertebral column; Unilateral – lateral flexion of vertebral column
N: Dorsal rami of spinal nn.
I: Lumborum – Angles of lower ribs Thoracis – Angles of upper ribs Cervicis – Cervical TPs
Longissimus Forms intermediate column
O: Posterior iliac crest, sacrum, sacral and inferior lumbar SPs and sacrospinous & supraspinous l.
A: Bilateral - extension of vertebral column; Unilateral – lateral flexion of vertebral column
N: Dorsal rami of spinal nn
I: Thoracis – Ribs (between tubercles and angles) and TPs in thoracic region Cervicis – Cervical TPs Capitis – Mastoid process
Spinalis Forms medial column
O: Posterior iliac crest, sacrum, sacral and inferior lumbar SPs and sacrospinous & supraspinous l.
A: Bilateral - extension of vertebral column; Unilateral – lateral flexion of vertebral column
N: Dorsal rami of spinal nn
I: Thoracis – SPs in thoracic region Cervicis – SPs in cervical region (often absent) Capitis – Cranium
- Can fuse with Semispinalis Capitis to form
the Biventer Capitis m.
Semispinalis Superficial layer of the group
O: TPs of C4-T12 vertebrae
I: Thoracis – SPs 4-6 vertebral segments superior Cervicis – SPs 4-6 vertebral segments superior Capitis – Occipital bone
A: Bilateral extension of all regions; contralateral rotation of all regions
N: Dorsal rami of spinal nn.
Multifidus Middle layer of the group Best developed in lumbar region
O: Sacrum, Ilium, Sacroiliac ll., TPs of T1-12 and articular processes of C4-7
I: SPs 2-4 segments superior
A: Stabilize vertebrae during local movements of vertebral column
N: Dorsal rami of spinal nn.
Rotatores Deepest of the three layers Best developed in thoracic region
O: TPs of vertebrae
I: Longus - SP 2 segments superior; Brevis –SP 1 segment superior
A: Stabilize vertebrae and assist with extension and rotatory movements; proprioception
N: Dorsal rami of spinal nn.
Interspinalis
Connect SPs cervical spine best chance to see it
O: Superior surfaces of SPs of cervical
and lumbar vertebrae
I: Inferior surfaces of SPs of vertebrae superior
A: Aid in extension and rotation of vertebral column
N: Dorsal rami of spinal nn.