Chapter 11 Part 1

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

polysnaptic

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

reverberation

Define stretch reflex.

"monosynaptic reflex" regulates skeletal muscle in length.

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

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

Where is spinal CSF located?

subarachnoid space

Describe the lumbar plexus and sacral plexus.

the lumbar plexus contains t12-l4. the sacral plexus forms l4-s4 and contains the sciatic nerve.

the spinal cord consists of five regions and ______ segments.

31

Differentiate between divergent and convergent neural circuits.

Divergent: spreads info from one neuron to several. Convergent: several neurons synapse on a single postsynaptic neuron.

Describe a dermatome.

a specific bilateral area of skin supplied by 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

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

phrenic nerves

List the components of a reflex arc.

receptor, sensory neuron, integration center, motor neuron, effector

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

she suffered no damage to spinal cord.

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

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

skin and muscles of back and neck and shoulders

Identify the basic characteristics of polysynaptic reflexes.

slow response. delay increases w number of synapses. at least 1 interneuron between sensory and motor.