Neuro 1 Flashcards
What are the 5 regions of the vertebral column?
- cervical
- thoracic
- Lumbar
- sacrum
- coccyx
What is the primary curvature?
a single primary curvature which has its anterior aspect concave in embryo
What happens to curvatures as we grow?
become upright the vertebral column has some secondary curvatures included, which have their concavity facing posteriorly
What are the 2 secondary curvatures?
Cervical and lumbar curvatures
Where do 2 primary curvatures exist?
in the thoracic and sacral regions of the vertical column
In what view should there be no curvatures in the spine?
anterior posterior view
In what view are there natural curvatures?
lateral view
When can these natural curvatures be exaggerated?
-due to degenerative conditions e.g. arthritis -can occur during pregnancy or increasing weight gain
Why does the natural curvature become exaggerated in pregnancy?
when the anterior aspect of the abdomen becomes more pronounced and therefore in order to remain upright additional curvatures are exaggerated
What are the typical features of vertebra?
- Vertebral body (anterior aspect)
- Vertebral foramen
- Spinous processes (project posteriorly)
- Pedicles
- Articular facets
What are pedicles connected by?
lamina
What do the the stacked vertebrae allow?
- flexibility in a number of different directions: 1. bending forward (flexion of vertebral column)
2. bending backwards (extension of cerebral column( and then lateral flexion bending to the sides or even rotation
What do intervertebral discs allow?
- some level of compression
- allow flexibility of the vertebral column
- acting as shock absorbers to transmit forces throughout the vertebral body to avoid fracturing of any vertebral components
What is characteristic of cervical vertebra?
- Transverse process
- Uncus of body (uncinate process)
- Rectangular bodies with concave superior and convex inferior surfaces
- Foramen trasnversarium !!
- Triangular vertebral foramen !!
- Bifid spinous process !!
- Oblique relatively horizontal articular facets directed primarily superiorly and inferiorly
- Perforated transverse processes with anterior and posterior tubercles
What is characteristic of thoracic vertebra?
- Long, strong transverse processes extend posterolaterally
- Columnar bodies, heart shaped in superior view
- Circular vertebral foramen, relatively small compared to size of body
- Nearly vertical articular facets directed primarily posteriorly and anteriorly
- Spinous process long and sloping: overlaps inferior vertebra
- Costal facets: 2 on each side of body and 1 on each transverse process
What is characteristic of lumbar vertebra?
- Massive columnar body, kidney shaped in superior view
- Vertebral foramen triangular, intermediate in size
- Nearly vertical articular facets directed primarily medially and laterally
- Short, broad and blunt spinous process
- Transverse processes longe and slender directed laterally
What does the different shape of the bones in different region of vertebral column mean?
- Can be recognised by things such as the presence that the shape of the vertebral canal in the middle and also the orientation of their facets
- so various regions the vertical column have different degrees of flexibility and different ranges of motions due to the orientation of these faces
What happens generally as you go top to bottom with the verteberal bodies?
- vertebral bodies get larger
- facets change from being more horizontally placed to being more vertically placed
- this has repercussions on the degree to which the various parts of the vertebral column move
What is C1 known as?
Atlas
What are the features of the atlas?
- NO vertebral body
- Lateral masses connected by anterior arch and posterior arch
- NO spinous process
- Each lateral mass contains a superior articular facet (for articulation with occipital condyles), and an inferior articular facet (for articulation with C2)
- anterior arch contains a facet for articulation with the dens of the axis (secured by the transverse ligament of the atlas – which attaches to the lateral masses)
- Posterior arch has a groove for the vertebral artery and C1 spinal nerve
What is C2 known as?
Axis
What are the features of the axis?
- Vertebral body which superior process (vertebral body pf C1) - odontoid process Dens)
- dens articulates with the anterior arch of the atlas, in doing so creating the medial atlanto-axial joint - this allows for rotation of the head independently of the torso
- axis also contains superior articular facets, which articulate with the inferior articular facets of the atlas to form the two lateral atlanto-axial joints
What is the cruciate ligament made up of?
- Superior longitudinal band
- Transverse ligament of atlas
- Inferior longitudinal band
What is the function of the cruciate ligament?
Stabilises atlanto-axial joint
What does the longitudinal band do?
Joins the body of the C2 to the anterior foramen magnum
What does the transverse band do?
Attaches to the inner margin of the C1 lateral masses on both sides
What does the alar ligaments do?
Limits the amount of rotation of the head
What type of joint is the atlanto-ocipital joint?
YES joint
What type of joint is the atlanto-axial joint?
NO joint
What does the crucitae ligament do?
Helps to stabilise the joints between the skull C1, C2 and limit excessive movement around these joints
What are two ligaments further down the vertebral column?
- Anterior longitudinal ligament
- Posterior longitudinal ligament
What are the ligaments present throughout the vertebral column?
- anterior and posterior longitudinal ligaments
- ligamentum flavum
- interspinous ligament
What does the ligamentum flavum connect?
connects the laminae of adjacent vertebrae
What does the interspinous ligament connect?
connects the spinous processes of adjacent vertebrae
What are two ligaments unique to the cervical spine?
- Nuchal ligament
2. Transverse ligament of atlas
What is the nuchal ligament?
- a continuation of the supraspinous ligament
- It attaches to the tips of the spinous processes from C1-C7 -provides the proximal attachment for the rhomboids and trapezius
What does the transverse ligament of the atlas connect?
the lateral masses of the atlas, and in doing so anchors the dens in place
What do intervertebral discs allow?
- some degree of flexibility such that they allow movement
- allow compression of the intervertebral joints
- allow some flexibility so that the unit of two vertebral bodies can move with respect to each other
When can discs become compressed?
when weight is put on - so when we walk, jump run or as we increase in weight intervertebral disc can become compressed
Why is there lots of pathology associated with discs?
- nerves that have to emerge from the vertebral canal come out between adjacent vertebrae at the point called the intervertebral foramen or foramina pleura
- anything that restricts the nerves passage through this intervertebral; foramen could cause impingement of the nerve
What is sciatica?
some of the lumbar nerves, lumbar sacral nerves become impinged when the substance of the disc comes out of the disc so that the disc is ruptured or herniated
How many spinal segments are there?
31
How many pairs of spinal nerves are there?
31
How many vertebrae are there?
30
How many pairs of spinal nerves and vertebrae are there in the cervical region?
8 Cervical (7 vertebrae)
How many pairs of spinal nerves and vertebrae are there in the thoracic region?
12 Thoracic (12 vertebrae)
How many pairs of spinal nerves and vertebrae are there in the lumbar region?
5 Lumbar (5 vertebrae)
How many pairs of spinal nerves and vertebrae are there in the sacral region?
5 Sacral (5 vertebrae)
How many pairs of spinal nerves and vertebrae are there in the coccygeal region?
1 Coccygeal (1 vertebra)
Where do C1-C7 nerves leave the vertebral column through intervertebral foramina?
above vertebrae
Where do C8-Coccygeal nerves leave the vertebral column through intervertebral foramina?
below vertebrae
Where is the cervical enlargement for the innervation of limbs?
(~C3-T1)
Where is the lumbar enlargement for the innervation of limbs?
(~L1-S2)
Where does the spinal cord physically end?
at about L1, L2 vertebral level
What is the cauda equina?
The nerve roots L2-S5 arise from the distal end of the spinal cord, forming a bundle of nerves known as the cauda equina
What type of nerves are spinal nerves?
mixed nerves that originate from the spinal cord, forming the peripheral nervous system
How does each spinal nerve begin?
as an anterior (motor) and a posterior (sensory) nerve root
How is a single spinal nerve formed?
roots arise from the spinal cord, and unite at the intervertebral foramina
How does the spinal nerve leave the vertebral canal?
via the intervertebral foramina, and then divides into two
What are the two things the spinal nerve divides into?
- Anterior rami
2. Posterior rami
What is anterior rami?
supplies nerve fibres to much of the remaining area of the body, both motor and sensory
What is posterior rami?
supplies nerve fibres to the synovial joints of the vertebral column, deep muscles of the back, and the overlying skin
What type of nerves are in the posterior root?
sensory
What type of nerves are in the anterior root?
motor
