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 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 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
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)
(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 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
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
osteoporosis may lead to what?
vertebral fractures because of the weight-bearing function of the spine
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 posterior surface of the centrum has one or two foramina for what?
the exit of basivertebral veins
___is posterior to the vertebral body and is formed of 2 pedicles and 2 laminae
vertebral arch AKA neural arch
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 is trefoil in shape in cervical, lumbar, and sacral regions of spinal column and circular and smallest in thoracic region?
short strong processes that project backwards from the upper portion of vertebral body
pedicles AKA roots
the superior and inferior vertebral notches of adjacent vertebrae contribute to the formation of what?
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 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 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