3 - Anatomy of Back & Shoulder Flashcards
How many vertebrae are there?
33
How many vertebrae of each region are there?
7 cervical
12 thoracic
5 lumbar
5 sacral
4 coccygeal
What is an abnormal excessive convex (outward) curvature of the spine called?
Kyphosis
What is an abnormal concave (inward) curvature of the spine called?
Lordosis
How many curves do babies have in their spine?
When does this change?
1 primary kyphotic curve
Changes when they start sitting and walking
How many curves do adults have in their spine?
They have 2 kyphosis & 2 lordosis
Kyphosis at thoracic & sacral regions
Lordosis at cervical and lumbar regions
What is a sideways curvature of the spine called?
Scoliosis
In which part of the vertebra does the spinal cord sit?
Vertebral foramen
What is a process on a vertebra?
It is a bony projection on the posterior of the vertebra - is a site of muscle attachment, articular processes form facet joints for movement & spinous processes allow for movement.
What are the three types of process on a vertebra?
Transverse process
Articular process (superior and inferior)
Spinous process
What are facet joints in the spine?
The joints formed by the superior articular process of one vertebrae articulating with the inferior articular process of the vertebrae above it.
What is formed by the articular processes of two vertebrae joining? What passes through this?
Intervertebral foramen
Spinal nerves pass in and out to the spinal cord here.
What pathology can be associated with intervertebral foramen?
Spinal nerve impingement
What is the anatomical name for the facet joint?
Zygopophysial joint
How can you tell if a vertebra is cervical?
It has a bifid (split), short spinous process - only vertebrae to have this
Has triangle shaped vertebral foramen.
What is uniquely formed by the transverse processes of the cervical foramen?
Foramen transversarium
What is contained within the foramen transversarium?
Vertebral vessels (artery, vein & lymph) + sympathetic plexus
Which two vertebrae of the cervical spine are atypical?
Atlas (C1) and Axis (C2)
How do the atlas & axis vertebrae differ from typical cervical vertebrae?
Atlas is ring shaped - has no body (its body has fused to C2).
C2 - has the “odontoid peg” (aka dens) which are the bodies of C1 & C2 which have fused together.
Which vertebrae is this?
Axis - C2 - can tell because it has the odontoid peg.
Which vertebrae is this?
Atlas - C1 - has no vertebral body and is ring shaped.
Is there a vertebral disc between C1 & C2?
No
Which ligament attaches to C1?
Transverse ligament
What does the top of C1 articulate with on the skull?
Occipital condyles
What is a hangman’s fracture?
Fracture that occurs on C2 behind the articular parts - causing the dens to prolapse and kill / paralyse by impinging spinal cord.
How does the body provide stability to the dens?
Ligaments run behind the dens, attaching to the skull - preventing the dens from prolapsing.
How can you identify a thoracic vertebra?
Have demifacets (superior and inferior) on side of body - these articulate with the ribs
The transverse process also has a facet (costal facet).
Has a heart-shaped body
Vertebral foramen is circular.
Which two places on a thoracic vertebrae does a rib articulate with?
The bodies of the vertebrae above and below the rib (at the demifacets) and on the transverse process (costal facet).
What does the superior demifacet of a vertebral body articulate with?
The rib of the same vertebral number.
What does the inferior demifacet of a vertebral body articulate with?
The rib below (I.e. T10 inferior demifacet articulate with T11 rib)
How can you identify typical lumbar vertebra?
They have a large body.
Have a long, thin, transverse process.
Vertebral foramen is triangular.
Articular processes tend to face inwards.
What type of vertebrae is this?
Thoracic vertebrae
= demifacets on side of body
= costal facet on transverse process
= heart-shaped vertebral body
= circular shaped vertebral foramen
What type of vertebrae is this?
Lumbar vertebrae
= large body
= long, thin transverse process
= triangular shaped vertebral foramen
= articular processes face inwards
How many fused bones make up the sacrum?
5
Is the sacrum concave anteriorly or posteriorly?
Anteriorly (convex posteriorly)
Why does the sacrum have a large articular surface? What is its name?
Sacroiliac joint (SIJ)
Articulates with the ilium here - large surface area
How many fused bones make up the coccyx?
3-4
Does the coccyx have a vertebral canal or arches?
No - as there are no coccygeal nerves which need to exit.
Why do intervertebral joints have different orientations at different levels of the spine?
It enables different types of movement at different parts of the spine
What are intervebral discs made of?
3 tough fibrous rings called annulus fibrosus, with a liquid centre (nucleus pulposes)
What type of joint is found between articular processes of vertebrae?
Synovial joints (facet or zygapophysial joints).
What is the nucleus pulposes derived from?
It is a remnant of the notochord
Why do we need strong spinal ligaments?
Most of the body weight is anterior to the spine = so we need strong ligaments to stop collapsing anteriorly
Which are the two ligaments which run anterior and posterior to the vertebral bodies of the spine?
Anterior and posterior longitudinal ligaments
Which is stronger - the anterior or posterior longitudinal ligament?
Posterior is strongest - resists flexion of the spine.
Anterior is slightly less strong - it resists extension of the spine.
Which ligament lies behind the spinous process?
The supraspinous ligament
Which ligaments run in between the spinous processes of the vertebra?
The interspinous ligaments
Which ligament attaches from the lamina of one vertebral arch to the lamina of the arch above (between the transverse process and the spinous process)?
Ligamentum flavum
What is the thickening of the supraspinous ligament between C7 & the skull called?
Ligamentum nuchae
What is the difference in function between extrinsic and intrinsic muscles of the back?
Extrinsic muscles - move upper limbs & ribs (breathing)
Intrinsic muscles - move vertebral column, maintain posture
Which muscles are the extrinsic muscles of the back?
The superficial and intermediate muscles
- Trapezius
- Latissimus dorsi
- Levator scapulae
- Rhomboid major & minor
- Serratus posterior (superior & inferior)
Which rami are the extrinsic and intrinsic muscles supplied by?
Extrinsic muscles - are supplied by the anterior rami
Intrinsic muscles - are supplied by the posterior rami