Vertebral column AKA
spinal column, back bone, spine
what is the main part of the axial skeleton
what componets make up the axial skeleton?
spine, skull, ribs, sternum, and hyoid bone
what is formed of alternating bony vertebrae and fibrocartilagenous intervertebral discs (IVD's)
what connects the vertebrae
strong ligaments, supported and moved by powerful musculotendinous masses
how many vertebrae in a newborn?
33 (7C 12T 5L 5S 4C)
how many true movable vertebrae in an adult?
24 (7C 12T 5L) also 2 falso vertebrae ( 1S and 1 C) 26 total
how long is the vertebral column in males?
71 CM 28 IN
C = 12.5 cm
T = 28 cm
L = 18cm
S and C = 12.5 cm
how long is the spine in females?
61 cm (25 in)
how much longer is the spine in the morning compared to in the evening? why is this?
2 inches due to the imbibition of water by IVD's
how many IVD's are there in the spine and what percent of the total lengh are they?
where is the first IVD located?
there are no IVD's located where?
where are the IVD's thickest? where are they smallest?
thickest - lumbar
smallest - cervical
what are the 2 major pyramids that are observed when the spine is viewed from the front
long upright pyramid ( c2 to L5)
short inverted pyramid (sacrum to tip of coccyx)
what the smaller pyramids is the long upright pyramid divided into?
an upright pyramid ( c2 - t1)
and inverted pyramid ( t1-t5)
an upright pyramid ( t5-l5)
how many surves if the spine can be viewed in the lateral view
4 curves 2 types
cervical - secondary curve/ lordotic curve
thoracic - primary curve / kyphotic curve
lumbar - secondary/ lordotic
sacral - primary/ kyphotic
at what age do each of these 4 curves form and what is their purpose?
cervical - 3-4 months (baby holds head erect)
thoracic - during fetal life
lumbar - 12-18 months ( walking)
sacral - during fetal life
how can you describe primary / kyphotic curves?
due to difference in height between anterior and posterior parts of vertebral bodies
accommodation curves, accommodate for thoracic, abdominal and pelvic viscera
how can you describe secondary/ lordotic curves?
due to difference in thickness between anterior and posterior parts of IVD's
compensation curves, compensate for a change in posture (holding head and walking)
how much axial pressure can the spine withstand?
(humpback) abnormal increase of the curve in the thoracic. could be due to osteoporosis
(sway back) increase in the lumbar curvature
seen in pregnate women to compensate for their line of gravity
obesity is a cause of lordosis
(croaked) abnormal lateral curve to the left or right
spinous processes point toward concavity
it may be structural (developmental) or functional ( mechanical or neurological)
what are the 5 functions of the vertebral column
protects the spinal cord
supports the weight of the body
flexible axis for the body and pivot for the head
posture and locomotion
resiliency : ability to absorb shock
what are the parts of a typical vertebrae
vertebral body and vertebral arch
what is the vertebral arch formed of?
one spinous process
2 transverse process
4 articular process (2 superior and 2 inferior)
what type of bone forms the vertebrae
outer layer is compact bone, core is trabecular (spongy) bone that contains red bone marrow
what is the pattern of trabeculation
it varies as it develops along the lines of greatest stress
irregular bone covered by periosteum that is innervated by nerve fibers that transmit pain and proprioception
what happens to the density of bone with age?
increases during puberty, reaches a peak during midtwenties, decreases gradually at menopause
decrease in bone density
osteoporosis may lead to what?
vertebral fractures because of the weight-bearing function of the spine
what is the largest part of the vertebrae?
vertebral body AKA centrum
what allows for the spine to bear the weight of the body?
its increase in size from above downward
what connects the bodies of successive vertebrae?
what structures concave posterioly and form the anterior part of vertebral foramina?
the bodies of the vertebrae
what is the upper and lower surfaces of the body covered by?
hyaline cartilage: cartilaginous end plate (CEP) / vertebral end plate
the anterior surface of the body shows foramina for what?
the posterior surface of the centrum has one or two foramina for what?
the exit of basivertebral veins
what are the signs of scoliosis?
curve in spine
___is posterior to the vertebral body and is formed of 2 pedicles and 2 laminae
vertebral arch AKA neural arch
the vertebral arch and the posterior surface of the vertebral body form what?
the succession of vertebral foramina in the articulated column forms the what?
vertebral canal AKA spinal canal
what does the spinal canal contain?
spinal cord, meninges, fat, nerve roots of spinal nerves, and blood vessels
what protects the spinal cord and associated structures?
what is trefoil in shape in cervical, lumbar, and sacral regions of spinal column and circular and smallest in thoracic region?
less than 15mm in diameter in lumbar region
what is the antero-posterior diameter of the vertebral canal in the lumbar region
short strong processes that project backwards from the upper portion of vertebral body
pedicles AKA roots
what forms the anterior part of the vertebral arch?
each pedicle possesses what?
a shallow superior and a deep inferior vertebral notch
the superior and inferior vertebral notches of adjacent vertebrae contribute to the formation of what?
what does the IVF contain?
spinal nerve roots, vessels, and dorsal root ganglia
what happens to the IVFs with age
their size decreases causes chronic neck pain
what is continuous with the pedicles?
what are flat, broad plates of bone that form the posterior part of the vertebral arch
what curves posteromedially to meet in the middle line at the spinous process?
how many processes arise from the vertebral arch of a typical vertebra?
a spinous process
2 transverse processes
4 articular processes ( 2 superior, 2 inferior)
what projects posteriorly from the vertebral arch at the junction of the laminae
what serves as levers for muscle attatchments
what projects laterally from the junction of the pedicles and laminae
what serves as muscle attatchment sites where rotation and lateral flexion of the spine can occur?
what are the two parts that make a transverse process?
true TP (posteriorly) and a costal element (anteriorly)
what are the cervical costal elements?
what do the thoracic costal elements develop into?
what are the lumbar costal elements
anterior aspects of TPs
what are the costal elements of the sacral
alae of sacrum (right and left)
what is the greek term for the articular processes
what structure arrises from the junctions of the pedicles and laminae? AKA pediculolaminar junction
the joint between inferior articular process of one vertebrae and the superior articular process of the vertebra below forms what?
zygaphophyseal (Z or facet joint)
the articular processes are oriented in different planes in different regions of the vertebral column and this affects what?
the type and range of motion in each region
what is the function of the articular processes
restrict movements in certain directions and prevent vertebrae from slipping anteriorly
what is each motion segment (functional spinal unit) of the vertebral column formed by?
2 vertebrae and 3 joints: IVD (anteriorly) and 2 facet joints (posteriorly)