Back Lecture 3 : Vertebral column, joints, ligaments Flashcards
The vertebral column consists of 33 vertebrae, namely :
7 cervical, 12
thoracic, 5 lumbar, 5 sacral, and
three to four coccygeal
vertebrae.
What do the sacral vertebrae fuse into?
The sacral vertebrae fuse into
a single bony element, the
sacrum.
What does the coccygeal vertebrae vary in? What does it often fuse into?
The coccygeal vertebrae vary
in number from three to four, and
often fuse into a single coccyx.
When does the vertebrae become larger?
The vertebrae becomes larger as it descends to the sacrum, from T4
downwards.
What is change in size related to?
Change in size is related to increase in body weight.
Where does the vertebrae reach its maximum size?
Just
above the sacrum, the vertebrae reaches its maximum size and the
weight is transferred to the pelvic girdle via the sacroiliac joint.
What does a typical vertebra contain?
A vertebral body, a vertebral and 7 processes
The vertebral body is the…
weight bearing part and is linked to adjacent vertebra via intervertebral
disc and ligaments
Where does the size increase?
Size increases inferiorly
What does the vertebral body consist of?
Spongy bone enclosed with compact bone
What are the superior and inferior surfaces covered with?
Superior and inferior surfaces are covered with hyaline cartilage ( absent in dried
specimens)
Describe the periphery.
Periphery is smooth- annular epiphysis, and unites to the centrum
What anchors the vertebral arch to the vertebral body?
Vertebral arch is anchored to the vertebral body by two pedicles, and consists
of pedicles and laminae.
What do the vertebral foramina form?
Vertebral Foramina together form the vertebral canal which contains the spinal
cord.
Where does the vertebral canal continue?
Vertebral canal continues superiorly with foramen magnum of the skull.
What is each pedicle notched on?
Each pedicle notched on its superior and inferior surface- superior and inferior
vertebral notches which form the intervertebral foramen
Where does the spinous process project?
Spinous process projects posteriorly from the junction of two laminae.
Where do the 2 transverse process extend?
2 Transverse processes extend poster laterally from junction of lamina and pedicle.
What do the 2 superior articular process and 2 inferior articular processes articulate?
2 superior articular process and 2 inferior articular process articulate forming
zygopophyseal joints.
Where does the spinal cord lie?
The spinal cord lies within
the canal
What is the spinal cord surrounded by?
Spinal cord is surrounded
by three connective tissue
membranes- meninges
What is the pia mater intimately associated with?
Pia mater-innermost layer:
intimately associated with
the spinal cord
What separates the arachnoid mater from the pia mater?
Arachnoid materseparated from the pia
mater by the subarachnoid
space contains CSF
What separates the dura mater from the bone?
Dura mater-is separated from the bone by the extradural/epidural space containing loose connective tissue, fat, venous plexus.
Where do the 31 pairs of spinal nerves emerge?
The 31 pairs of spinal nerves emerge from the vertebral canal between pedicals and adjacent vertebrae-intervertebral foramina
The 31 pairs of spinal nerves :
8 cervical(C1-C8), 12
thoracic (T1-T12), 5 lumbar
(L1-L5), 5 sacral(S1-S5), 1
coccygeal (Co)
What helps each spinal nerve to attach to the spinal cord?
Each spinal nerve is attached
to the spinal cord via anterior
and posterior roots.
What does each nerve do after exiting the vertebral canal?
After exiting the vertebral canal via the intervertebral foramen each spinal nerve, branch off into anterior and posterior ramus.
What is the intervertebral foramen formed between?
The foramen is formed between
adjacent vertebral arches and
related to intervertebral joints.
What are the superior and inferior margins formed by?
Superior and inferior margins are
formed by notches of adjacent
pedicles
What is the anterior border formed by?
Anterior border is formed by the
intervertebral disc between the
vertebral bodies of the adjacent
vertebrae
What is the posterior margin formed by?
Posterior margin is formed by the
articular processes of the vertebral
arches and associated joints.
What can the pathology that reduces the size of the intervertebral foramen affect?
Pathology that reduces the size of the intervertebral foramen eg. herniation of IV disc can affect the function of the associated spinal nerve
What are the distinguishing features of the vertebrae?
The foramen transversarium of the cervical vertebrae and a thoracic vertebrae that has rib elements as well as a lumbar vertebrae with a large size
The sacral vertebrae fuse into a…
large triangular bone
The coccygeal vertebrae fuse into a…
small triangular bone
A typical cervical vertebra[C3-C6] has the following features :
1. Vertebral body is square shaped 2. Each transverse process has foramen tranversarium 3. Spinous process is short and bifid 4. Vertebral foramen is triangular
The Atlas(C1) and Axis(C2) are specialized to :
Accommodate the movement of the head
Describe the Atlas.
C1- major distinguishing factor-lacks a vertebral body. Ring shaped and composed of two lateral masses interconnected by anterior and posterior arch
Atlas and Axis What does each lateral mass articulate with?
Each lateral mass articulates with the occipital condyle (atlanto-occipital joint) and below with the sup articular facets of C2.
Anterior arch-articular facet for
dens of C2. What holds the dens in position?
Dens is held in
position by the transverse
ligament of the atlas.
What does the dens act as?
Dens acts as pivot that allows
the atlas and attached head to
rotate from side to side- atlanto-axial join
What is the axis characterised by?
C2(axis) is characterised by the
dens which projects from the
vertebral body.
What is the dens?
Dens are circular impressions for
alar ligament that connect the
dens to the medial surfaces of
the occipital bone.
What does a typical thoracic vertebra have?
• Superior and inferior costal facets (partial facets) on each side of the
vertebral body for articulation with the head of the own rib and the
head of the rib below.
• Each transverse process has facet for articulation with tubercle of its
own rib.
• Vertebral body-heart shaped, vertebral foramen is round.
Describe the Lumbar vertebra.
The Lumbar vertebra is large in size
Lumbar vertebra : Describe the transverse processes.
Transverse processes are generally thin and long, except for L5
which is massive for attachment of illiolumbar ligament.
Lumbar vertebra : Where is the mammillary process found?
The mammillary process is found on the superior articular facet
Describe the vertebral body and the foramen.
Vertebral body is cylindrical and foramen is triangular.
Describe the sacrum and how it is formed.
Five fused bones to form one triangular bone. Concave anteriorly.
What does the sacrum articulate with above and below?
Articulates above with L5 and below with coccyx
The sacrum has :
- Laterally-two L shaped facets for articulation with the pelvic bones
- Four pairs of anterior and posterior sacral foramina
Describe the coccyx.
The coccyx is a small triangular bone with no vertebral canal
The joints include :
- Joints of the vertebral bodies
- Joints of the vertebral arches
- Craniovertebral joints
- Costovertebral joints
- Sacroiliac joints
What are the joints of the vertebral bodies formed by?
Formed by layer of hyaline cartilage on each vertebral body and an
intervertebral(IV) disc which lies between the layers.- Secondary
cartilaginous joints
What does an intervertebral disc consist of?
IV disc- outer annulus fibrosus and inner nucleus pulposus
What do degenerative changes of the annulus fibrosus lead to?
Degenerative changes of the annulus fibrosus can lead to herniation
of the nucleus pulposus and cause impingement of spinal nerve
roots.
UNCOVERTEBRAL
JOINTS : The lateral margins of a typical
cervical vertebrae are…
elevated uncinate processes
What type of joints are uncovertebral joints?
Synovial joints
What do the elevated uncinate processes articulate with?
These processes articulate with
the vertebral body above to form
JOINTS OF THE
VERTEBRAL ARCHES:
Zyogpophyseal joints are…
synovial joints between the
superior and inferior articular
facets on adjacent vertebrae
What does the articular capsule attach to and what does it enclose?
An articular capsule attaches to
margin of the articular facets and
encloses each joint
CRANIOVERTEBRAL JOINTS:
ATLANTO-OCCIPITAL
AND ATLANTO-AXIAL JOINTS
Craniovertebral joints are…
synovial joints with no IV discs
What do atlanto-occipital joints permit?
Atlanto-occipital joints- permit flexion and extension-nodding
movement YES, synovial condyloid
The atlanto-axial joint has…
3 articulations, 2 lateral atlanto-axial joints (plane), 1
median atlanto axial joint( pivot) pivot movement ( turning from side to
side)- NO
The ligaments that support joints :
- Anterior longitudinal ligament[ALL]
* Posterior longitudinal ligament[PLL]
What is the anterior longitudinal ligament attached to superiorly?
Attached superiorly to the base of the skull
and runs the length of vertebral column to
insert inferiorly to the anterior surface of
the sacrum.
Where is the posterior longitudinal ligament located?
On the posterior surface of the vertebral body
The similarity between the anterior and posterior longitudinal ligament.
Like
the (ALL) attached along the length of the
vertebral column to IV discs and vertebral
bodies.
What is the tectorial membrane?
Upper part of the PLL that
connects C2 to the base of the skull is
called the tectorial membrane.
Where does the ligamenta flava/flavum lie and where does it run?
Lies between adjacent laminae on each side. Runs between the
posterior surface of the laminae below to the anterior surface the laminae
above.
What does the ligamenta flava/flavum form?
Forms part of the vertebral canal
The function of the ligamenta flava/flavum :
Function: resist separation of laminae during flexion and assist in
extension.
What does the supraspinous ligament connect and where does it pass?
Supraspinous ligament: connects and passes along the tips of spinous
processes of C7-sacrum.
Where does the ligamentum nuchae become distinct?
From vertebra C7 to skull the ligament becomes distinct- Ligamentum nuchae
Describe the ligamentum nuchae.
• Ligamentum nuchae- triangular in median sagital plane.
Attachments of the supraspinous ligament and the ligamentum nuchae :
Attachments: base- external occipital protuberance to foramen magnum
Apex :
Apex- tip of spinous process of C7
Functions of the supraspinous ligament and the ligamentum nuchae :
FXN: supports head, provides muscle attachment
Where is the vertebrae positioned?
Positioned posteriorly in the
body at the midline.
When the vertebrae is viewed laterally, it has…
4 curvatures
Describe the primary curvature.
Primary curvature -concave
anteriorly- in the thoracic and
sacral regions
Describe the secondary curvature.
Secondary curvatures -
concave posteriorly-in the
lumbar and cervical regions