Anatomy of Back, Spine and Spinal Cord Flashcards
What are the extrinsic muscles of the back?
Rhomboids, trapezius, levator scapulae and latissimus dorsi = attach back to pectoral girdle and move upper limb
Where are the intrinsic back muscles located?
Entirely within the back = maintain back posture and move the spine
What are the two groups of intrinsic back muscles?
Erector spinae = superficial
Transversospinalis = deep
What are some features of erector spinae?
3 vertical muscle groups located lateral to the spine
Low back pain may be due to erector spinae strain
What is the inferior attachment of erector spinae?
Common tendon attaches to sacrum and iliac crest
Where do individual muscle fibres of erector spinae attach superiorly via a tendon?
Either a rib (between angles and tubercles), transverse process of a vertebra or a spinous process of a vertebra
Where is transversospinalis located?
Located within the groove between the transverse and spinous processes
Where do the individual muscles fibres of transversospinalis attach between?
A vertebra and the skull
A vertebra and a rib
One vertebra and another
Sacrum and a vertebra
What is the nerve supply to the intrinsic muscles of the back?
Segmental nerve supply as per dermatome/myotome pattern
Posterior rami branches
What are the functions of the intrinsic muscles of the back?
Help maintain posture
Support the spine
Extend the spine
What happens when erector spinae contracts?
Bilateral contraction = extension of spine
Unilateral contraction = lateral flexion of spine
What muscles are involved in flexion of the spine?
Psoas major and rectus abdominis
What are the typical features of the cervical vertebrae?
Transverse foramen, bifid spinous process and triangular vertebral foramen
What are some features of C1 (atlas)?
No body or spinous process
Has posterior arch and superior arch instead
What are some features of C2 (axis)?
Has odontoid process
Projects superiorly from body