Anatomy and Tracts of the Spinal Cord

Segments

Divisions of the spinal cord including cervical, thoracic, lumbar, and sacral.

31 pairs

Number of spinal nerve pairs in humans.

About 18 inches

Length of the spinal cord, varying based on an individual's height.

Cervical & lumbar enlargements

- The cervical enlargement, which extends between C3 to T1; and the lumbar enlargements which extends between L1 to S2

- Thickened areas of the spinal cord that supply nerves to the upper and lower limbs.

Conus medullaris

Tapered end of the spinal cord.

Cauda equina

Bundle of spinal nerves below the spinal cord.

Gray matter

Region of the spinal cord composed of nerve cell bodies and dendrites.

White matter

Region of the spinal cord composed of myelinated axons.

Horns

Projections of gray matter in the spinal cord, including dorsal, ventral, and lateral horns.

Ascending tract transmits:

Sensory information

Descending tracts transmits:

Motor information

Dorsal root ganglion

Cluster of nerve cell bodies of sensory neurons.

Posterior columns - fasciculus gracilis (hint: you have graceful legs)

Carries somatosensory stimuli including fine touch, vibration, and proprioception from the lower limbs

Posterior columns - fasciculus cuneatus (hint: you have cutting hands)

Carries somatosensory stimuli including fine touch, vibration, and proprioception from the trunk, neck, and upper limbs

Anterolateral system - spinothalamic tracts

Carries stimuli about pain, temperature, and certain types of touch

Corticospinal tracts

Carries motor stimuli from the motor areas of the cerebral cortex

Spinal cord passes through the

foramen magnum

The spinal cord:
1. Contains only motor neurons
2. None of the statements provided are correct for the spinal cord
3. contains only interneurons
4. Is exactly as long as the vertebral canal
5. Contains only sensory neurons

None of the statements provided are correct for the spinal cord

There are _____ pairs of lumbar spinal nerves and _____ pairs of sacral spinal nerves

Five (5)-5

There are _____ pairs of cervical spinal nerves and _____ pairs of thoracic spinal nerves

Eight (8) - 12

As a result of a viral infection, a patient has suffered destruction to the anterior gray horns in the lumbar region. What manifestation would you expect from this neurologic damage:

Deterioration of motor activity in the legs and feet

The tail end of the spinal cord is not "hanging loose." it is actually anchored via the ____, which connects to the coccyx bone.

Filum terminale

The spinal cord is enlarged at the ______ and ______ regions

Cervical - lumber

The spinal cord runs from the foramen magnum to the level of the _______ vertebra

1st Lumber

_______________ are found within the dorsal root ganglion

Cell bodies of sensory neurons

The conus medullar is the tapering point at the end of the spinal cord. It is located at approximately at the level of

L1- 12

Which of the following are potential causes for spinal cord injuries?
1. Violent injuries
2. Motor vehicle collisions
3. Sport injuries
4. All the listed events may contribute to spinal cord injury
5. Falls

4. All the listed events may contribute to spinal cord injury

Which of the following transmit information from the spinal cord to the extremities of the body?

Ventral root

which of the following is NOT one of the four regions into which the spinal cord is divided?

Coccygeal

There are ________ pairs of spinal nerves.

Thirty-one (31)

Diagnostic tools to assess spinal cord injury include:
1. X-ray
2. MRI
3. All listed diagnostic tool are used to assess spinal cord injury
4. CT scan

3. All listed diagnostic tool are used to assess spinal cord injury

The spinal cord consists of ascending and descending tracts. Which of the following is correct in reference to those tracts?

Both tracts are found in the white matter. The ascending tract transmits sensory information while the descending tracts transmit motor information.

The inferior end of the spinal cord is anchored to the coccyx by the

Filum terminale

The reflex arc contains a:
1. sensory reception
2. motor neuron
3. all the listed are components of the reflex arc
4. sensory neuron

3. All the listed are components of the reflex arc

The spinal cord is continuous superiorly with the

Medulla oblongata

The deep groove on the ventral surface that extends the length of the spinal cord is the

Anterior median fissure