Normal Curvatures of the Spinal Column Flashcards
How are curvatures of the vertebral column identified?
according to the direction the convexity of the curve faces
What are the curvatures of the vertebral column?
anterior, posterior, and lateral
What is the direction of the primary curve of the vertebral column?
posterior
What embryonic event causes the direction of the posterior curve of the vertebral column?
the embryonic disc will undergo flexion in a cranial to caudal direction
Why is the posterior curve also called the primary curve?
it is the first curve to appear embryologically
What are the adult remnants of the primary curve along the vertebral column?
- the thoracic or dorsal curve
- the pelvic or sacrococcygeal curve
What are the names given to curves that form during development to reverse the direction of regions along the vertebral column?
anterior curve, secondary curve, or compensatory curve
What are the names of the anterior curves?
- cervical curve
- lumbar curve
What segmental levels form the cervical curve?
C2-T1
What segmental levels form the lumbar curve?
T12-L5
What is the earliest time of appearance of the cervical curve?
3rd fetal month
What is the traditional time of appearance of the cervical curve said to be?
during the last trimester in utero
What is the time during which the “adult” cervical curve is said to appear?
within the first year after birth
What developmental events are indicated in the formation of the adult cervical curve?
- centers for vision and equilibrium will appear in the brain
- musculature attaching the skull, cervical region, and upper thorax together develops
- the head is held upright
- the intervertebral disc height becomes greater anterior than posterior
At what age will the infant begin to hold the head erect?
usually between the 3rd and 4th month after birth
What is the name given to the integration of visual and motor pathways associated with holding the head erect?
the righting reflex
What is the location for the apex of the cervical curve?
typically between C4 and C5
What is the location for the cervical kyphosis (primary cervical curve)?
between occiput and C1
What is the vertebral relationship between the cervical curve and the cervical enlargement?
- cervical curve C2-T1
- cervical enlargement C3-T1
What is the time of appearance of the lumbar curve?
between 12 and 18 months after birth
What infant activities are associated with the development of the lumbar curve?
crawling and walking
What developmental events are indicated in the formation of the adult lumbar curve?
- crawling will cause the abdomen to put tension on the lumbar region and pulls it forward
- muscle development is promoted to compensate for the swayback of the lumbars
- intervertebral disc height will become greater anterior compared to posterior
- walking will further promote muscle and intervertebral disc development
What happens within the intervertebral disc to facilitate the lumbar curve development?
the nucleus pulposus of L4 will shift its position within the annulus fibrosis
Which sense is a requirement for holding the head erect, standing, sitting, and walking?
vision
