ANS Fundamentals
This neurotransmitter is released by all preganglionic autonomic neurons.
What is acetylcholine?
The vertebral column has these four primary functions.
What are protection of the spinal cord, support of body weight, serving as the central axis of the body, and support of posture/movement?
Unlike nearly every other skeletal muscle group, the intrinsic back muscles receive motor innervation from these nerves.
What are the dorsal (posterior) rami?
This structure forms the gel-like center of the intervertebral disc.
What is the nucleus pulposus?
A patient reports numbness isolated to the middle finger following a cervical injury. This spinal nerve root is most likely affected.
What is C7?
This division of the ANS has short preganglionic neurons and long postganglionic neurons.
What is the sympathetic nervous system?
A vertebra with a vertebral artery running through its transverse process and no vertebral body is most likely this specific vertebra.
What is the atlas (C1)?
A patient has isolated injury to the dorsal rami at the lumbar levels. Extension of the vertebral column would be primarily impaired due to weakness of this muscle group.
What is the erector spinae?
Most lumbar disc herniations occur at these two levels.
What are L4-L5 and L5-S1?
During a neurologic exam, a patient cannot abduct their fingers against resistance. This spinal level is primarily being tested.
What is T1?
Preganglionic sympathetic neurons originate from these spinal cord levels.
What are T1-L2?
A fracture through the pars interarticularis without displacement is known as this lesion.
What is spondylolysis?
List the erector spinae muscles from lateral to medial.
What are iliocostalis, longissimus, and spinalis?
A patient has severe low back pain after repeatedly lifting boxes with a flexed spine. The physician suspects a herniated disc. Which component of the disc has most likely ruptured to allow displacement of the nucleus pulposus?
What is the annulus fibrosus?
A patient demonstrates weakness when extending the great toe but has normal ankle plantarflexion. This myotome is most likely involved.
What is L5?
This cranial nerve carries parasympathetic fibers to most thoracic and abdominal viscera.
What is the vagus nerve (CN X)?
An oblique radiograph demonstrates the classic "Scotty Dog" appearance. A fracture of this region is identified.
What is the pars interarticularis?
A patient who cannot retract the scapula but has preserved shoulder abduction likely has dysfunction of this muscle and its corresponding nerve.
What is the rhomboid major (or minor) supplied by the dorsal scapular nerve?
A patient has lumbar radiculopathy. MRI reveals a detached fragment of nucleus pulposus that has migrated into the epidural space. This type of herniation is called:
What is sequestration? [HYN Back and Spine | PDF]
A patient presents witt numbness of the thumb and weak elbow flexion, a lesion of what spinal nerve root would explain both findings
What is C6?
A patient develops damage to neurons located in the intermediolateral cell column of T1-L2. This component of the ANS is primarily affected.
What is sympathetic outflow?
A patient develops sudden respiratory arrest after traumatic rupture of a ligament stabilizing the dens, allowing posterior displacement into the spinal cord. Which ligament most likely ruptured?
What is the transverse ligament of the atlas?
A stab wound selectively injures posterior rami in the thoracolumbar region. Which movement is expected to be most impaired?
What is extension of the vertebral column?
A patient has acute back pain with leg weakness. MRI reveals a herniated disc, but the physician delays imaging for several weeks. Why is immediate imaging not routinely recommended for uncomplicated disc herniation?
What is because many herniated discs are asymptomatic and conservative management is recommended unless red flags are present?
A patient has difficulty standing on tiptoes, loss of sensation along the posterior leg, and decreased sensation along the lateral foot
Which spinal nerve root is most likely compromised?
What is S1?