Back Muscles Flashcards
THE VERTEBRAL COLUMN
Functions:
• Supports the skull, pectoral girdle,
upper limbs, thoracic cage
• Transmits body weight to the lower
limbs by way of pelvic girdle
• Gives great protection to the spinal
cord, roots of spinal nerves and
covering meninges within its cavity
Cervical =
Thoracic =
Lumbar =
total vertebrae
1-7
1-12
1-5
=33
GENERAL CHARACTERISTICS OF A VERTEBRA
❑ Vertebral Body anteriorly
❑ Vertebral Arch posteriorly
❑ Pedicles at the sides
❑ Laminae at the center
❑ 7 processes:
1 spinous process
2 transverse processes
4 articular processes
❑ Vertebral Foramen within
❑ Vertebral Notches
❑ Intervertebral Foramen
- No body
- No spinous process
- Superior articulation: Occipital condyles
- Inferior articulation: Axis
Altas (C1)
Has a peglike odontoid process (dens)
Axis (C2)
- A single, small triangular bone
- Consists of 4 vertebrae fused
together
COCCYX
- Synovial joint
- Flexion, extension, and lateral flexion
Atlanto – Occipital Joint
- Synovial joint
- Extensive rotation of the atlas and thus of the
head on the axis
Atlanto-Axial Joint
- Joint between 2 vertebral bodies
- Extend from C2 to the sacrum
- Thickest in cervical and lumbar regions
- Serve as shock absorbers
INTERVERTEBRAL DISCS
- Peripheral part of the disc
- Fibrocartilage (concentric layers)
Annulus fibrosus
- Central part of the disc
- Gelatinous material
Nucleus pulposus
- Wide
- Strongly attached to the front
and sides of vertebral bodies
and intervertebral discs - Weak and narrow
- Attached to the posterior
borders of the disc
LIGAMENTS OF THE VERTEBRAL COLUMN
CURVES OF THE VERTEBRAL COLUMN
One continuous anterior concavity
Raise head → Cervical Concavity
Stand upright → Lumbar Concavity
Cervical:
Posterior concavity
Thoracic:
Posterior Convexity
Lumbar:
Posterior Concavity
Sacral:
Posterior Convexity
MUSCLES OF THE BACK
3 groups
• Superficial Muscles
– connected with shoulder girdle
• Intermediate Muscles
– movements of the thoracic cage
• Deep / Postvertebral Muscles
– belong to vertebral column
Muscles of longest length:
Lie superficially
Run vertically from sacrum to the ribs
Muscles of intermediate length:
Run obliquely from transverse processes
to the spinous processes
Muscles of shortest length:
Run between spines and between
transverse processes of adjacent vertebrae
Superficial Vertically Running Muscles
Erector spinae -
iliocostalis
longissimus
spinalis
Intermediate Oblique Running Muscles
Transversospinalis -
Semispinalis
multifidus
Rotatores
Deepest Muscles
Interspinales
Intertransversarii
