Anatomy - Back and Spine Flashcards
what are the two main functions of the back?
maintain posture
movement
what do the skin dimples on the back indicate?
the positions of the posterior superior iliac spines (PSIS)
what are the three parts of the trapezius from superior to inferior?
descending
transverse
ascending
where to the extrinsic back muscles attach?
the pectoral girdle
what do the extrinsic back muscles do?
move the upper limb
what are the four extrinsic muscles of the back?
rhomboids
levator scapulae
trapezius
latissimus dorsi
where are intrinsic back muscles located?
entirely within the back
what are the roles of the intrinsic back muscles?
maintain back posture
move the spine
what are the two groups of intrinsic back muscles?
erector spinal (superficial) transversospinalis (deep).
what three muscles make up the erector spine?
iliocostalis
longissimus
spinalis
where do the erector spinal muscles attach inferiorly?
sacrum + iliac crest via a common tendon
where does iliocostalis attach superiorly?
rib
where does longissimus attach superiorly?
transverse process
where does spinals attach superiorly?
spinous process
where is transversospinalis located?
in the grooves between the transverse and spinous processes
how many vertebrae are there in total?
33
how many cervical vertebrae are there?
7
how many thoracic vertebrae are there?
12
how many lumbar vertebrae are there?
5
how many sacral vertebrae are there?
5 - fused to form 1 sacrum
how many coccygeal vertebrae are there?
4 - fused to form 1 coccyx
describe how the size of the vertebrae changes from superior to inferior
become larger as they bear more weight
become smaller again once weight has transferred to the hips
what are the two secondary curvatures of the vertebral column?
cervical lordosis
lumbar lordosis
what are the two primary curvatures of the vertebral column?
thoracic kyphosis
sacral kyphosis
what is the vertebral arch made of?
2 x pedicles
2 x laminas
what is the role of the vertebral foramen?
conveys and protects the spinal cord
how do articular processes allow mobility with adjacent vertebrae?
via synovial facet joints
where is an intervertebral foramen located?
between two adjacent vertebrae
what is located in an intervertebral foramen?
spinal nerves
where are facet joints located?
between articular processes of adjacent vertebrae
what disease process can affect facet joints?
arthritis
where are intervertebral discs located?
between the bodies of adjacent vertebrae
where in the vertebral column are there no intervertebral discs?
between C1 and C2 or in the sacrum and coccyx
what are the two parts of an intervertebral disc?
outer fibrous ring
inner soft pulp
what is the outer fibrous ring of an intervertebral disc called?
annulus fibrosus
what is the inner soft pulp of an intervertebral disc called?
nucleus pulposus
name the five ligaments found in the vertebral column
ligamentum flavum posterior longitudinal ligament anterior longitudinal ligament supraspinous ligament interspinous ligament
what is the role of the ligamentum flavum?
connects adjacent laminae posterior to the spinal cord
what is the role of the posterior longitudinal ligament?
prevents over flexion of the spine
what is the role of the anterior longitudinal ligament?
prevents over extension of the spine
what is the role of the supraspinous ligament?
connects the tips of the spinous processes
what is the role of the interspinous ligaments?
connects superior and inferior surfaces of adjacent spinous processes
what is C1 called?
atlas
describe the structure of the atlas
no body or spinous process
posterior and anterior arches
ligament
what is C2 called?
axis
why is the axis an atypical vertebrae?
contains the odontoid process
what is C7 called?
vertebrae prominens
what passes through the transverse foramina of all cervical vertebrae except C7?
vertebral arteries
where are the atlanto-occipital joints found?
between occipital condyles of the base of the skull and the superior articular facets of the atlas
what type of joints are the atlanto-occipital joints?
synovial
why do the atlanto-occipital joints have a loose capsule?
to help enable movements of the skull
what movements occur at the atlanto-occipital joints?
flexion and extension of the neck
a little lateral flexion and rotation
how many articulations are there in atlanto-axial joints?
three
what are the three articulations of the atlanto-axial joints?
two between inferior articular facets of the atlas and the superior facets of the axis
one between the anterior arch of the atlas and the odontoid process of the axis
what is the main movement of the atlanto-axial joints?
rotation
where does the spinal cord begin?
foramen magnum
it is continuous with the medulla oblongata
where does the spinal cord end?
vertebral level L1-L2
can actually end anywhere between T12 and L3
what is the end of the spinal cord called?
conus medullaris
what is the spinal cord surrounded by in the vertebral canal?
three layers of meninges and epidural fat
where is the needle inserted for spinal and epidural anaesthetic?
L3/4 interspace
what determines the safest place for spinal/epidural anaesthetic insertion?
subarachnoid around the cauda equina, not the spinal cord
vertebrae not fused
what is the cauda equina made of?
L2-Co spinal nerve roots descending towards their intervertebral foramina
where does the subarachnoid space end?
at the level of S2
when should lumbar puncture NOT be performed?
cases of raised ICP
where is spinal anaesthetic injected?
into the subarachnoid space
where is epidural anaesthetic injected?
into the epidural space
where is anaesthetic injected in caudal anaesthesia?
sacral hiatus
what is the aim of caudal anaesthesia?
to anaesthetise the sacral spinal nerve roots of the cauda equina
what does laminectomy involve?
the removal of one or more spinous processes and the adjacent lamina
