Spine Flashcards
What is the surface landmark to locate the 3rd thoracic vertebra?
Spine of the scapula.
What is the principle role of the erector spinae muscles?
Control/limit flexion of the back.
What muscles fails to hold the scapula flat against the back when its inner action is lost, hence the term “winged scapula”?
Serratus anterior muscle.
What sort of curvature should be considered “normal” in a healthy persons lumbar vertebral column?
Lordosis
Why is the spine curved?
It increases mobility and ability to bear the axial load.
What is a scoliosis?
An abnormal lateral curvature of the spine.
It can be congenital, idiopathic or neuromuscular.
What is the surface landmark for T7?
At the level of the inferior angle of the scapula.
What is the surface landmark of L4/5?
At the level of a line drawn between the iliac crests.
At what level does the spinal cord terminate?
L1/L2. Cauda equina is below.
What is muscle tone?
Muscles resistance to passive stretch.
What is muscle power?
Tension generated by voluntary contraction.
Neurotome
Area of skin innervated by one peripheral nerve.
Dermatome
Area of skin innervated by one spinal nerve. Important in evaluating extent of a spinal injury.
Myotome
Group of muscles innervated by one spinal nerve. Important in evaluating extent of a spinal injury.
Explain posterior convexity
Thoracic and sacral kyphosis are backward curving primary curves.
Explain anterior convexity
Cervical and lumbar lordosis are forward curving secondary curves.
When and why do the secondary curves come from?
Initially spine is C shaped at birth. Cervical lordosis develops at about 6 months to improve lifting of the head and head control. Lumbar lordosis develops at 10-14 months to allow standing and walking.
What is C1 also known as?
‘Atlas’. Greek Titan who had to hold up the sky.
Why do most fractures occur at the junction between cervical and thoracic and thoracic and lumbar?
Stress difference. Thoracic is relatively immobile- biomechanical increase in stress between a stiff and moveable segment.
What is a tendon reflex?
An involuntary muscle contraction response to the sudden stretch of its tendon. It tests the integrity of a 2 neurone reflex arc innervated by a single segment of the spinal cord.
What examination findings would there be if the afferent pathway of a reflex was damaged?
Reflex is absent with associated sensory loss.
What examination findings would there be if the efferent pathway of a reflex was damaged?
Reflex is absent with with associated muscle paralysis.
What is the cause of hyper-reflexia (tonic, brisk reflexes)?
A cortico-spinal pathway above the segment which modulates muscle activity is damaged.
What is muscle tone?
Muscle resistance to passive strength.
What is muscle power?
Tension generated by voluntary contraction.
What is a lower motor neurone lesion?
Injury to the nerve fibres travelling from the anterior horn of the spinal cord to the muscles eg. spinal cord injury, traumatic division of a peripheral nerve.
What is an upper motor neurone lesion?
Injury to the neural pathway above the motor neurones in the anterior horn of the spinal cord eg. stroke, traumatic brain injury, cerebral palsy.
What is the tone, power and reflexes on examination of a lower motor neurone lesion?
Tone-reduced. Power-reduced. Reflexes- hypo-reflexia.
What is the tone, power and reflexes on examination of a upper motor neurone lesion?
Tone-increased. Power-spasticity. Reflexes- hyper-reflexia.
How many vertebrae are there in each spinal segment?
Cervical (8). Thoracic (12). Lumbar (5). Sacral (5). Coccygeal (1). Total of 31. Each segment gives rise to a pair of spinal nerves.
