Spinal Cord Anatomy & Clinical Correlates

A comprehensive set of Q&A flashcards covering spinal cord termination, anatomy, root functions, matter organization, pathways, dermatome landmarks, and clinical injury correlates.

Where does the adult spinal cord typically terminate?

Around the level of the first lumbar vertebra (L1).

What is the tapered, cone-shaped end of the spinal cord called?

The conus medullaris.

Below the conus medullaris, the bundle of spinal nerves resembles a horse’s tail and is called the .

Cauda equina.

Name the ligament that laterally anchors the spinal cord to each vertebra.

Denticulate ligament.

What is the vertical ligament that anchors the conus medullaris to the coccyx?

Filum terminale.

In the spinal cord, which matter (white or gray) is peripheral?

White matter is on the outside; gray matter is central.

How is the gray/white matter arrangement of the brain different from that of the spinal cord?

In the brain gray matter is outer and white matter is inner—the reverse of the spinal cord.

What neuronal component predominates in white matter?

Myelinated axons.

What neuronal component predominates in gray matter?

Neuron cell bodies.

Which spinal root carries purely motor fibers?

The ventral (anterior) root.

Which spinal root carries purely sensory fibers?

The dorsal (posterior) root.

After exiting the vertebral column, the dorsal and ventral roots merge to form a .

Spinal nerve containing both motor and sensory fibers.

The spinal nerve quickly splits into posterior and anterior , both containing mixed fibers.

Rami (posterior ramus and anterior ramus).

Which ramus (anterior or posterior) is typically larger and why?

Anterior ramus; it innervates the larger anterior body wall and limbs.

What type of neuron has its cell body in the dorsal root ganglion?

Pseudo-unipolar sensory neuron.

Ascending spinal tracts carry information, while descending tracts carry information.

Ascending carry sensory; descending carry motor.

In general, the anterior (ventral) half of the spinal cord contains more pathways.

Motor.

How many neurons are typically involved from brain to effector in a motor pathway?

Two neurons.

How many neurons are typically involved from receptor to brain in a sensory pathway?

Three neurons.

Map of skin areas supplied by specific spinal nerves is called a .

Dermatome.

Which dermatome level aligns roughly with the nipple line?

T4.

Which dermatome level aligns with the umbilicus?

T10.

Spinal cord injury at C4 or above threatens what vital function?

Independent breathing (respiratory failure).

Complete injury at C8 or above results in , whereas injury at T1 or below leads to .

Quadriplegia; paraplegia.

Injury at T6 may cause shock affecting heart rate and blood pressure.

Neurogenic shock.

Damage around L1–L2 can disrupt bladder control, leading to or bladder.

Spastic or flaccid bladder.

True or False: Complete transection of the posterior spinal cord chiefly abolishes motor function below the lesion.

False; it primarily abolishes sensory function.