how many vertebrae are in the vertebral column?
how many individual vertebrae are there?
what is the organization of the vetebrae of the vertebral column?
7 cervical, 12 thoracic, 5 lumbar, 5 fused sacral (sacrum), 4 fused coccygeal (coccyx)
what are pedicles?
processes that project dorsally to attach the body to the arch
what are laminae?
unite to form the spinous process
what fails to use in spina bifida?
laminae fail to fuse to form a spinous process
compare the following types of spina bifida:
1. spina bifida occulta
2. spina bifida cystica
a. with meningocele
b. with meningomyelocele
c. with myeloschisis or rachischisis
1. one or more spinous processes fail to form at lumbar or sacral levels; asymptomatic; marked by tuft of hair over defect usually
2. cyst protrudes through the defect
a. cyst lined by the dura and arachnoid and contains CSF
b. lumbosacral spinal cord is displaced into the cyst which stretches lumbosacral spinal nerves and may result in bladder, bowel, or lower limb weakness
c. caudal end of the neural tube fails to close in the dorsal midline and is exposed on the surface of the back
at what vertebral levels is spina bifida most commonly seen?
lumbar or sacral
what are costal processes?
usually form transverse processes that project laterally at the junction between each lamina and pedicle
label the components of the vertebrae
what are the primary curvatures of the vertebral column and how are they directed? secondary curvatures?
primary are the thoracic and sacral curvatures, convex directed posteriorly
secondary are the cervical and lumbar curvatures, convex directed anteriorly
what is kyphosis?
abnormal increase in the posterior curvature of the spine
thus, increased curvature in the thoracic or sacral regions
what are possible causes of kyphosis? which is the most common?
postural (most common)
anterior wedge-shaped thoracic vertebrae
resorption of the anterior parts of the thoracic vertebral bodies from osteoporosis
what is lordosis? what is a common cause?
abnormal increase in the anterior curvature of the spine
thus, increase in curvature in the lumbar or cervical regions
weakening of the anterior abdominal wall as a result of weight gain can cause
what is scoliosis? what is a common cause?
abnormal lateral curvature that may be caused by an absent half of a vertebra or a wedge-shaped vertebra or by an asymmetric weakness of back musculature
where are the zygapophyseal or facet joints located? what is their function?
between the facts of superior and inferior processes at the junction of each pedicle and lamina
permit gliding motion
acted on by intrinsic or deep back muscles
where are intervetebral disks located? what are their components? what is their function?
situated between bodies of most adjacent vertebrae
consist of a fibrocartilaginous annulus fibrosus surrounding a nucleus pulposus
functions to absorb shock and distribute weight over the entire surface of vertebral bodies durring compression and tension
what is the nucleus pulposis a remnant of?
where is the anterior longitudinal ligament found and what is its function?
covers the anterolateral parts of the vertebral boes and the disks to limit vertebral extension
where is the posterior longitudinal ligament found and what is its function?
covers the posterior part of the vertebral codies and the disks and functions to limit vertebral flexion
which is greater (thicker/stronger), the anterior or posterior longitudinal ligaments?
where are the elastic ligamentum flavum and what are their functions?
between the laminae of adjacent vertebrae
function to limit vertebral flexion and help maintain normal vertebral curvatures
where are the interspinous and supra spinous ligaments located?
interspinous ligaments a ligament connect the spinous processes of two adjacent vertebra
supraspinous ligaments a ligament connect the tips of the spinous processes of thoracic and lumbar vertebrae
where are the intervertebral foramina located? what are they bounded by? what do they transmit?
an opening between the pedicles of adjacent vertebrae, separating individual vertebrae
bounded by the pedicles of adjacent vertebrae, posteriorly by facet joints and anteriorly by the bodies/intervertebral disks
transmit dorsal and ventral roots of the spinal nerves
where/what is the vertebral canal? what does it contain?
the opening formed by the combination of the body and the vertebral arch as well as the ligaments/disks that interconnect them
contain the meninges, spinal cord, and roots of spinal nerves
where is the epidural space and what does it contain?
outside the dural layer of the meninges and contains fat and the internal vertebral venous plexus
what is the internal venous plexus? what is significant about it clinically in relation to cancer?
connects veins that drain the thorax, abdomen, and pelvis with dural venous sinuses of the cranial cavity
provides routes for metastasis of neoplasms of the prostate, uterus, and rectum to the cranial cavity
what is the dura mater and where is it located?
outermost covering of the spinal cord, it forms the dural sac containing the spinal cord within vertebral canal
continuous with the meningeal dura of the cranial cavity and ends at S2, with lateral extensions at the roots of spinal nerves
what is the subdural space?
potential space between the dura and the arachnoid mater
what is the arachnoid mater and where is it located?
intermediate one of the three layers of meninges
also extends to S2 and is pressed against the dura by the pressure of CSF