Spinal Chord Final

In ________, axon collaterals extend back toward the source of the impulse and further stimulate the earlier neurons.

reverberation

The outward projections from the central gray matter of the spinal cord are called

horns

Enlargements of the spinal cord occur

in segments of the spinal cord that control the limbs

Blood vessels that supply the spinal cord are protected by the...

pia matter

A(n) ________ reflex has at least one interneuron placed between the sensory and motor neurons.

polysynaptic

Cerebrospinal fluid flows within the..

subarachnoid space

Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the

subarachnoid space

When an anesthetic blocks the function of the anterior rami of the cervical spinal nerves, which areas of the body will be affected?

the skin and muscles of the back of the neck and of the shoulders.

The spinal cord consists of five regions and ________ segments.

31

Damage to which nerve of the cervical plexus would interfere with the ability to breathe?

Damage to the phrenic nerves, which innervate the diaphragm

Differentiate between divergent and convergent neural circuits.

In divergent neural circuits, information spreads from one neuron to several neurons. In convergent neural circuits, several neurons synapse with a single postsynaptic neuron.

Describe the lumbar plexus and sacral plexus.

The lumbar plexus is a nerve network formed by axons from the anterior rami of spinal nerve segments T12-L4; the sacral plexus is a nerve network formed by the anterior rami of spinal nerve segments L4-S4.

List the components of a reflex arc.

a receptor, a sensory neuron, a motor neuron, and a peripheral effector; interneurons may also be present.

Describe a dermatome.

a specific bilateral sensory region monitored by a single pair of spinal nerves.

Of the spinal meninges, the middle one is the ________ mater.

arachnoid

In which plexus does the ulnar nerve arise?

brachial

The posterior root ganglia mainly contain..

cell bodies of sensory neurons

Tina falls while climbing a tree and lands on her back. Her frightened parents take her to the emergency room, where she is examined. Her knee-jerk reflex is normal and she exhibits a plantar reflex (negative Babinski reflex). These results suggest that..

didn't

Where is spinal CSF located?

found in the subarachnoid space, which lies deep to the epithelium of the arachnoid mater and superficial to the pia mater.

Define stretch reflex.

monosynaptic reflex that provides automatic regulation of skeletal muscle length.

Identify the basic characteristics of polysynaptic reflexes.

reflexes involve pools of interneurons, involve more than one spinal segment, involve reciprocal inhibition, and have reverberating circuits.

In the condition ________, a virus infects posterior root ganglia, causing a painful rash whose distribution corresponds to that of the affected sensory nerves as seen in their dermatomes

shingles