Topic 4: The Spinal Cord

Question 1

The ______ ____ links the brain and the rest of the body.

Answer 1

Spinal Cord

Question 2

The spinal cord extends from the _______ ______ to vertebrae L1-2.

Answer 2

Foramen magnum

Question 3

The ______ _________ is the cone-shaped end of the spinal cord.

Answer 3

conus medullaris

Question 4

The lumbar and sacral spinal nerves exit from the conus medullaris to form the _____ ______.

Answer 4

cauda equina (“horse’s tail”).

Question 5

T/F: The cauda equina is part of the PNS.

Answer 5

True

Question 6

The spinal cord segments for S1-S5 are level with T__-L_ vertebrae.

Answer 6

T12-L1 vertebra

Question 7

In a Spinal Tap, a needle is inserted between two lumbar vertebrae below the _____ ________. A sample of CSF is removed from the subarachnoid space, the area between the arachnoid membrane and the pia mater.

Answer 7

conus medullaris

Question 8

__________ (“without sensation”) is a state of controlled, temporary loss of sensation that is induced for medical purposes.

Answer 8

Anesthesia

Question 9

A spinal cord segment is the area of the spinal cord from which a pair of ______ and ______ roots attach. Within the cord itself there are no distinct boundaries between these segments.

Answer 9

Dorsal and ventral roots

Question 10

The anterior and posterior nerve roots combine on each side to form the spinal nerves as they exit the vertebral canal through the _________ _______.

Answer 10

Intervertebral foramina

Question 11

The ______ root carries afferent information.

The ______ root carries efferent signals from the SC to muscles and viscera.

Answer 11

The dorsal (posterior) root carries afferent information.
The ventral (anterior) root carries efferent signals from the SC to muscles and viscera.

Question 12

A _________ is an area of skin supplied by peripheral nerve fibers (axons) originating from a single dorsal root ganglion (DRG) .

Answer 12

Dermatome

Question 13

Because sensory information from the body is relayed to the CNS through the dorsal roots, the axons originating from the DRG cells are classified as _______ ______ ________, and the dorsal root’s neurons are the first order (1°) sensory neuron.

Answer 13

Primary sensory afferents

Question 14

T/F: The amount of grey and white matter is the same at each SC level.

Answer 14

False: The amount of grey and white matter varies at different SC levels.

Question 15

The ____ matter consists of the cell bodies of neurons, neuroglia, “mostly” unmyelinated axons, and the dendrites of interneurons and motor neurons.

Answer 15

Gray

Question 16

Unipolar axons entering the dorsal horn usually synapse with hundreds of ___________.

Answer 16

Interneurons

Question 17

All sympathetic nervous system outflow is via the T_-L_ cell bodies in the lateral horn. The Sympathetic NS is therefore referred to as the thoracolumbar division of the ANS.

Answer 17

T1-L2

Question 18

The Parasympathetic NS is also known as the _____ _____ division of the ANS.

Answer 18

Cranial sacral

Question 19

Most sensory tract names begin with “spino-, indicating they begin in the spinal cord. Their name will end with the part of the brain where the tract leads. For example, the spinothalamic tract travels from the spinal cord to the ______.

Answer 19

thalamus

Question 20

Tracts whose names end in “-spinal” are _____.

Answer 20

Motor

Question 21

_____ ______ is a condition where the space in the vertebral canal narrows. It narrows because of degenerative changes in the vertebrae. These changes cause excessive bone growth (osteophytes), ligament hypertrophy, or loss of spinal disc height.

Answer 21

Spinal stenosis

Question 22

People with spinal stenosis find a ____ _______ position while walking or sitting down helps decompress the area and relieve the pain.

Answer 22

Bent forward

Question 23

In severe cases _________ is an option to immediately relieve the pressure off the nerves.

Answer 23

laminectomy

Question 24

A person’s level of injury is defined as the ________ level of full sensation and function.

Answer 24

Lowest

Question 25

T/F: A C3 spinal cord injury means that everything below C3 is affected.

Answer 25

True

Question 26

C4 injury: _________ complete paralysis below the neck

Answer 26

Tetraplegia (quadriplegia)

Question 27

C_ injury: partial paralysis of hands and arms as well as lower body.

Answer 27

C6

Question 28

T6 injury:__________ ; results in paralysis below the chest

Answer 28

Paraplegia

Question 29

L_ injury: results in paralysis below the waist

Answer 29

L1

Question 30

The _______ horn contains the cell bodies of lower motor neurons. LMN axons leave the spinal cord.

Answer 30

Ventral

Question 31

LMNs that leave the ___ innervate mm. of the body (e.g. biceps brachii).
LMNs of the motor cranial nerves (those that leave the _________) usually innervate the mm. of the head (e.g., masseter via CN V).

Answer 31

LMNs that leave the SC innervate mm. of the body (e.g. biceps brachii).
LMNs of the motor cranial nerves (those that leave the brainstem) usually innervate the mm. of the head (e.g., masseter via CN V).

Question 32

__________ tracts from the brain synapse with lower motor neurons cell bodies in the ventral horn.

Answer 32

Descending