Lecture 8: Interactive Anatomy of the Back/Neuro Flashcards
What do the spinous processes create?
greater surface area for ligament and muscle attachment in each region
Why does the shape of the spinous process differ in the cervical region?
in the cervical region they are often bifid, creating greater leverage for more precise movements
Why does the shape of the spinous process differ in the thoracic region?
in the thoracic region they are elongated and more inferiorly directed; this helps limit extension of the thoracic region, protecting the rib cage
Why does the shape of the spinous process differ in the lumbar region?
in the lumbar region the processes are thick and “tall” (superior to inferior), creating a large area for muscle attachment that can support greater forces from bigger muscles
What intervertebral movements are possible between typical cervical vertebrae?
typical cervical vertebrae can be flexed, extended, laterally flexed and rotated against each other
What determines the movements possible between typical cervical vertebrae?
angulation of the superior and inferior articular facets determines this
How are superior and inferior facets of typical cervical vertebrae angled?
angled approximately halfway between a coronal plane and a transverse plane, these obliquely-oriented facets permit the most movement in the vertebral column
What happens when a muscle is free to concentrically contract?
its attachments are brought closer together
the muscle is shortened, usually creating a visible movement
When do eccentric contractions occur?
when a given muscle is contracted but greater forces exist that prevent it from shortening
What are some examples of forces which prevent muscles from shortening when they are contracting?
the more powerful contraction of another muscle, or an external force, such as gravity acting upon a heavy weight held in the hands
How does an eccentric contraction control the rate and extent of movement?
slows the lengthening of the muscle, caused by the opposing, greater force
