Musculoskeletal System 2 Flashcards
Vertebral column
- support, movement and protection
Typical vertebra
Vertebral body
- weight transfer
- IVDs between
Vertebral Arch
- forms vertebral foramen
- surrounds and protects spinal cord
Vertebra parts
- pedicel: foot of arch
- transverse process- muscle/ligament attachment (+ribs in thorax)
- lamina: lateral and posterior part of arch
- spinous process- muscle/ ligament attachment
- superior/inferior articulate processes- form joints
- superior/ inferior vertebral notches- form intervertebral foramen ( for spinal nerves)
Vertebral canal and spinal nerves
- vertebral column grows faster than the spinal cord
- spinal cord ends L1/L2
- spinal nerves descend to exit= cauda equina
- 8 cervical spinal nerves - C1 nerve exits above C1 vertebra
Movement of vertebral column
- cervical- most mobile
- thoracic- least mobile for flexion/extension/lateral bending
- lumbar- least rotation
Vertebral joints
- zygapophyseal (facet) joints- synovial, plane
- symphysis (intervertebral discs)- secondary cartilaginous
- typical vertebra forms 6 joints: 4 zygapophyseal, 2x IVD
Intervertebral disc
- fibrocartilaginous joints of the vertebral bodies
• provides stability and flexibility
• pressure regulation
• water- cushion function- shock absorber
-annulus fibrosis:
- high tensile strength
- fibrous sheath on outer surface- collagen layers in rings
- fibrocartilage inner zone
Nucleus pulpwood: high resilience, gelatinous structure, 80%-85% water
Burden on the intervertebral disc
Short lasting -
Incompressible, deformable water cushion. The annulus fibrosis counter acts the pressure arising from the nucleus polypody’s due to the burden on the spine
Long lasting-
When pressure applies: slow release of water from the Buckie pulposus, the IVD becomes thinner
- when relief: re-hydration of the nucleus polposus
- during the day: about 1% reduction of the body height
Slipped disc
- prolapse of IVD hernia
- tear in the annulus firbrosus- nucleus polposus can protrude
- can impinge on spinal cord or nerves
Atlas (C1) and Axis (C2)
C1- no body
C2- odontoid process (dens)
No IVD between C1-C2
Atlanto- occupital (C1- base of skull)
- nodding head “yes” joint
- atlanto- axial (C1-C2)
- synovial pivot
-shaking head “no” joint
Ligaments of the spine
Function
- connect bone to bone, provide support to joints, restrict movement at joints
Anterior+ posterior longitudinal ligament
Anterior
- base of skill to anterior surface of sacrum
- attached to anterior surface vertebral bodies and IVD’s
- prevents hyper extension
Posterior
- attached to C2 to sacrum- attached to posterior surface vertebral bodies and IVD’s
-lines the anterior surface of the vertebral canal
- weakly resists hyperflexion
Supraspinous and nuchal ligament
Sypraspinous
- C7- sacrum
- connects tips of spinous processes
- cord like
Nuchal ligament
- strong fibroelastic tissue
- base of skull to C7
- supports head and neck
- provides attachment for muscle
Ligaments between verts
- ligaments flava
• pass between laminae, form party of vertebral canal, resist separation of beets during flexion - interspinous
• between spinous processes - intertransverse
• between transverse processes
Intrinsic muscles
- all act directly on the spine
-embryonically develop in the back - all supplied by posterior rami of spinal nerves
- maintain posture and control movement of vertebrae
- superficial, intermediate, and deep layers
Thoracolumbar fascia
- covers deep muscles of back
- critical to organisation and integrity of the region
- latissimus dorsi and trapezius attached to it
Superficial layer- splenius muscle
- thick and flat
- origin: spinous processes and bottom of nuchal ligament
- insert- base of skull, mastoid process (capitis)/ transverse processes c1-c3 (cervicis)
- action- bilateral: extend neck: unilateral, rotate head to one side
Intermediate layer
- primary extensions of vertebral column
- 3 volume of muscle
- common origin: B-road tendon attached to sacrum,spinous processes of L and lower T verts, iliac
- illocostalis: inserts angles of ribs and C transverse processes
- longissimus: inserts T and C transverse processes and mastoid process
- spinal is: inserts T spinous processes and skull
Deep layer
- transversospinalis: fill groove between transverse and spinous processes
- semispinalis, multifidus, rotatores
- cross multiply vertebrae
- extend and rotate
- additional muscles
• levatores costarum
• interspinales and intertransversarii
