cervical and lumbar (anteriorly convex curves) thoracic and sacral (anteriorly concave curves)
What type of curve does the fetus have?
In the fetus, there is only a single anteriorly concave curve.
What type of curve is present when the child begins to hold his head erect?
When does the lumbar curve develop?
The lumbar curve develops as the child begins to walk.
When are all curves fully developed?
What are primary curves?
- thoracic and sacral are formed during fetal development
What are secondary curves?
- cervical is formed when infant raises head at 4 months - lumbar forms when infant sits up & begins to walk at about 1 year
What is kyphosis?
Kyphosis (humpback) is characterized by an abnormal increase in the thoracic curvature. It can result from erosion of the anterior part of one or more vertebrae, such as demineralization resulting from osteoporosis.
What is Dowager's hump?
Dowager's hump is a colloquial name for kyphosis in older women caused by wedge fractures of the thoracic vertebrae resulting from osteoporosis, but kyphosis occurs in both male and female geriatric patients.
What is lordosis?
Lordosis (sway back) is characterized by an anterior rotation of the pelvis at the hip joints producing an abnormal increase in the lumbar curvature. It is often associated with weakened trunk musculature.
Women develop temporary lordosis when?
Women develop temporary lordosis during late pregnancy to compensate for alterations to their normal line of gravity.
What is scoliosis?
Scoliosis (curved back) is characterized by an abnormal lateral curvature that is accompanied by rotation of the vertebrae. The spinous processes turn toward the cavity of the abnormal curvature. When bending over, the ribs protrude. Scoliosis is the most common deformity of the vertebral column in pubertal girls.
Intervertebral foramina are 2 vertebral notches together.
How many cervical vertebrae are there?
What is the first cervical vertebra?
The first cervical vertebra is the atlas. It supports the skull.
What is the second cervical vertebra?
The second cervical vertebra is the axis, which permits side-to-side rotation of the head.
What do the 3-6 vertebrae correspond to ?
The third to sixth correspond to the structural patterns of the typical cervical vertebrae.
What is the seventh vertebra called?
The seventh called the vertebra prominensis somewhat different from vertebrae 3 through 6.
What are the characteristics of the typical cervical vertebrae (C3-C6)?
- Smaller bodies but larger spinal canal - Transverse processes: shorter, with transverse foramen for vertebral artery - Spinous processes of C2 to C6 often bifid - 1st and 2nd cervical vertebrae are unique -atlas & axis
What does the transverse foramina transmit?
The transverse foramina transmit the vertebral arteries.
What are the craniovertebraljoints?
-Atlanto-occipital joint between the atlas and occipital bone of the skull
-Atlantoaxial joint between the atlas and axis
What type of joints are they?
What type of motion do the craniovertebral joints have?
They have a wider range of movement than the rest of the vertebral column
-ring of bone, has superior facets for occipital condyles -nodding movement at atlanto-occipital joint signifies "yes"
-dens or odontoid process is body of atlas -pivotal movement at atlanto-axial joint signifies "no"
Example of Atlas
The tectorial membrane goes through what?
Foramen magnum to the central floor of the cranial cavity.
How many thoracic vertebrae are there?
There are 12 thoracic vertebrae
These vertebrae articulate with the ribs
What are some characteristics of the thoracic vertebrae?
Larger and stronger bodies
Longer transverse & spinous processes
Facets or demifacets on body for head of rib
Facets on transverse processes (T1-T10) for tubercle of rib
Example of Facets and Demifacets
Explain Rib Articulation
Tubercle articulates with transverse process
Head articulates with vertebral bodies
How many lumbar vertebrae are there?
There are 5 lumbar vertebrae
They are the largest and strongest vertebrae in the column
Explain Lumbar Vertebrae
Strongest & largest
Short thick spinous & transverse processes -back musculature
How many bones are in the sacrum?
The sacrumis formed by the union of 5 sacral vertebrae, S1 -S5 (usually by age 30 years), and serves as a strong foundation for the pelvic girdle.
What is the auricular surface?
The auricular surface is the site of the synovial part of the sacroiliac joint. The name is derived from its resemblance to an ear. It is covered with hyaline cartilage during life.
What does the sacrum contain?
The sacral canal is the continuation of the vertebral canal in the sacrum.
It contains the nerve roots of the cauda equina.
The median sacral crest represents what?
Median sacral crest represents fused rudimentary spinous processes.
Medial (intermediate) crests represent?
fused articular processes
What are Lateral sacral crests?
Lateral sacral crests are tips of transverse processes of fused sacral vertebrae.
Example of Sacrum
How does the large sacral hiatus form?
Spinous processes are not present on S5 and sometimes S4, resulting in formation of a large sacral hiatus due to the absence of the spinous processes and associated laminae.
What does the sacral cornu represent?
The inferior articular process of S5 vertebra, and is a helpful guide to the location of the sacral hiatus.
Example of Coocyx
Inferior Portion of Sacrum
How is the coccyx formed?
The coccyx is formed by the fusion of 4 coccygeal vertebrae, generally by age 30
What are the coccygeal cornua?
rudimentary articular processes
What is caudal anesthesia?
- Caudal anesthesia (epidural block), frequently used during labor - A local anesthetic agent injected into the sacral canal at the sacral hiatus, which causes numbness in the regions innervated by the sacral and coccygeal nerves (approximately from the waist to the knees) - sacral and coccygeal cornu are important landmarks
What are intervertebral discs?
Between adjacent vertebrae absorbs vertical shock Permit various movements of the vertebral column Fibrocartilagenous ring with a pulpy center
Example of Vertebral Disc
Why do we lose height when we get older?
Nuclei pulposi lose turgor and become thinner due to dehydration and degeneration as one ages.
What happens if their is degeneration of the posterior logitudinal ligament?
If degeneration of the posterior longitudinal ligament and wearing of the anulus have occurred, the nucleus pulposus may herniate into the vertebral canal and compress the spinal cord or the nerve roots of the cauda equina.
What happens when an intervertebral disc protrudes?
When an intervertebral disc protrudes, it may compress the nerve roots numbered one inferior to the disc.
Explain hyperflexion of the neck.
The most commonly ruptured IV discs are those between C5 / C6 and C6 / C7, thereby compressing spinal nerve roots C6 and C7, respectively
Explain hyperextension of the neck.
Severe hyperextension of the neck may stretch or tear the anterior longitudinal ligament. (Whiplash)
What are zygapophysial joints?
The joints of the vertebral arches are the zygapophysial joints (facet joints)
They are plane synovial joints between the superior and inferior articular processes of adjacent vertebrae
What is the function of zygapophysial joints?
The zygapophysial joints permit gliding movements between the vertebrae.
What are accessory ligaments?
Accessory ligaments unite the laminae, transverse processes,and spinous processes,and help stabilize the joints.
What is foraminal stenosis?
Foraminal Stenosis means narrowing of one or more spinal foramina, commonly at C5/6 and C6/7 in the neck, and at L3/4, L4/5, and L5/S1 in the low back.
What are the symptoms for foraminal stenosis?
Symptoms: associated with back or neck pain with sciatica or brachialgia. In the lumbar region it may be associated with sciatic pain particularly after standing or walking for prolonged periods, due to settlement in the spine decreasing the diameter of the foramen
Example of Ligaments of the Verterbral Column
What is the anterior longitudinal ligament?
The anterior longitudinal ligament is a strong, broad fibrous band that covers and connects anterior aspects of vertebral bodies and intervertebral discs
Where is it located?
It extends from the atlas to the sacrum
What does the ligament do?
The ligament maintains stability of the joints between vertebral bodies, and helps prevent hyperextension of the vertebral column
What is the posterior longitudinal ligament?
The posterior longitudinal ligament runs within the vertebral canal along the posterior aspect of the vertebral bodies It is narrower and weaker than the anterior longitudinal ligament
What does the ligament do?
It helps prevent hyperflexion of the vertebral column and herniation or posterior protrusion of the discs
It is amply supplied with nociceptive nerve endings
What is the ligament flava?
The ligamenta flava (L. flavus = yellow) are broad, yellow elastic fibrous tissue that join laminae of adjacent vertebral arches
What do they do?
They prevent separation of the vertebral lamina, arrest abrupt flexion of the vertebral column, and help prevent injury to the intervertebral discs.
What does the supraspinouss ligament do?
The supraspinous ligament joins tips of spinous processes from C7 to the sacrum
What is the ligamentum nuchae?
The ligamentum nuchae is a thickening of the supraspinous ligament in the neck, extending from C7 to the occipital protuberance
Example of Ligaments of Vertebral Column
Example of Blood Supply of Vertebra
What is a segmental artery?
In general, a segmental artery is related around each vertebra, and supplies it
Where do the spinal arteries enter?
Spinal arteries enter the IV foramina and divide, then are distributed to dorsal and ventral roots of spinal nerves and their coverings
Example of Venous Drainage
Spinal veins form venous plexuses located where?
- Anterior vertebral venous plexus, both internal and external - Posterior vertebral venous plexus, both internal and external
What are basivertebral veins?
Basivertebral veins are large and tortuous, and are in the substance of the vertebral bodies
Intervertebral veins accompany what?
Intervertebral veins accompany the spinal nerves through the IV foramina and receive blood from the spinal cord and vertebral plexuses
What is unique about the vertebral venous plexus?
It is a valveless system.
it is clinically significant because it can transmit cancer metastases to distant locations that do not lie in the normal venous pathway.