Gross anatomy of the back Flashcards
What is the normal number of bones in the vertebral column
33
what are 5 roles of the vertebral column
- Firms rigid central axis which bears the weight of the body
- Provides attachment for movement of limbs
- provides support for the head
- protects the spinal cord
- continues haematopoiesis throughout life (longer than other bones) and stores calcium
How many cervical vertebrae are there?
7
what vertebrae attach to the ribs
Thoracic
how many thoracic vertebrae are there
12
How many lumbar vertebrae are there
5
How many many bones form the fused Sacrum
5
How many bones make up the coccyx
2-4
how many regions does the vertebral column have
5
What are the 2 types of curvature of the vertebral column
Primary curvature - Kyphosis
Secondary curvature - Lordosis
why does the vertebral column have curvatures
to distribute weight
What type of curvature exists in the 5 regions of the vertebral column
Kyphosis(1st) - Thoracic & Sacral + coccygeal
Lordosis (2nd) - Cervical & Lumbar
In what order does the spine develop its curvatures
primary (kyphosis) in fetus
1st secondary (lordosis) - cervical 3 months
2nd secondary - lumbar 12-15 months (standing and walking)
what are superior and inferior articular processes
two upward and 2 downward projecting processes located at the lateral parts of the vertebral arch of a thoracic vertebra They extend from the junction between the pedicles and laminae
What is the vertebral body
anterior of vertebrae, weight bearing
What is the vertebral foramen
hole in the middle of the vertebra
what is the neural (vertebral arch)
formed by pedicles and laminae extend from the sides of the vertebral body to join the body to the arch
What are the lamina of the vertebrae
thin sheet beside the spinous process
what is the spinous process
central protruding spike
what are the transverse processes
2 lateral protrusions beside laminae
What is the pedical of the vertebrae
stick out from the back part of the vertebral body, providing side protection for the spinal cord and nerves
What are the structures of a typical cervical vertebrae
-bifid spinous process
-modified transverse process (short)
-transverse foramen
-rectangular body
-uncinate process on main body
-triangular vertebral foramen
What vertebrae connects to the skull
C1 -atlas (yes vertebra)
what are the properties of the C1 vertebrae
-no vertebral body
- anterior & posterior arch
- concave support facet-connects to skull
- flat inferior facet
- groove for vertebral artery
- facet for Dens (2nd vertebra)
what are the properties of the C2 (axis) vertebra
-odontoid process/dens- c1 uses to pivot
-flat superior facets
-bifid spinous process
What are the properties of a typical thoracic vertebrae
circular foreman
thick transverse process
heart shaped vertebral body
transverse costal facet
superior & inferior costal demifacet
facets are rib articulations
what animal does a thoracic vertebrae look like
GIRAFFE
What are the properties of a typical lumbar vertebrae
-large bean shaped vertebral body
-narrow triangular vertebral foramen
-long thin transverse process
-broad quadrangular spinous process
-curled articular facets
- mammillary process
- accessory process
what animal does a lumbar vertebrae resemble
moose
What are the features of the sacrum
-sacral plateau
-ala - fused transverse processes
- anterior sacral foreman (holes on anterior)
-transverse ridge
-aricular surface where hip bones attach
- medial sacral crest (fused short version of spinal process)
-sacral hiatus - an opening present bottom of the sacral canal
-
describe the coccyx
-2 to 4 fused vertebrae
- coccygeal cornu - little horns at top of coccyx attach to sacrum
-top vertebrae has transverse process
What is the joint between vertebral bodies
intervertebral symphysis
what is the joint between the articular processes
zygapophyseal joint - synovial planar gliding joints
What are the 2 components of the intervertebral symphysis
Anulus fibrosa and nucleus pulposus which is force through the AF
what does the intervertebral symphysis do
its a shock absorber and brace stabilizer
What are the joints specific to the cervical spine
- atlanto-occipital joints (between atlas and skull) (yes)
-Atlanto-axial joints (between atlas and axial) (no) - uncovertebral joint - sit on each side of cervical disk allow stability in lateral flexion
What are the joints supporting the thoracic spine
-costovertebral joint (where rib attaches to vertebral column)
- costotransverse joint (connect ribs to transverse process)
how do you name the ribs
name is bases in the transverse process it articulates with so rib sits above corresponding vertebrae
what are the supporting joints of the lumbosacral spine
-Lumbosacral symphysis
-sacrococcygeal joint
-sacroiliac joint (links the sacrum to the hip bone)
What are the 2 muscle layers of the back
extrinsic and intrinsic
what are the extrinsic muscles layers of the back
-superficial layer ( control upper limb)
- intermediate layer (control respiration)
what is the intrinsic muscles layer of the back
- deep layer (postural and move vertebral column + head)
What are the superficial layer muscles of the back?
- trapezius
- latissimus dorsi
- rhomboid major & minor
- levator Scapulae
what are the intermediate layer muscles of the back
serratus posterior superior & inferior (rib cage movement and respiration)
What are the deep layer muscles of the back
- Spinotransversales group (extension + rotation of the head)
-Erector spinae group - Spinalis, longissimus, iliocostalis (extensors of the vertebral column)
-transversospinales (primary extensors)
what are the spinal cord rootlets
rootlets are the axon bodies exiting from the spinal cord which then come together to form the spinal nerves
where do the spinal nerves exit the vertebral column
through the intervertebral foramen
what is the membrane protecting the spinal cord
meninges
how do nerves S1-S4 exit the sacrum
through anterior and posterior sacral foramen
where does S5 and the coccygeal nerve exit the vertebral column
the sacral canal
what nerves are in the anterior rootlets
motor neurons traveling away
what nerves are in the posterior rootlets
sensory nerves traveling towards SC
