Chapter 13 Study guide

Vocabulary-style flashcards covering the organization of the spinal cord, spinal nerves, plexuses, neural circuits, and various types of reflexes based on the Chapter 13 Study Guide.

Spinal cord gray matter

A region that integrates information and initiates commands; it is dominated by the cell bodies of neurons, neuroglia, and unmyelinated axons.

Spinal cord white matter

A region that carries information from place to place and contains a large number of myelinated and unmyelinated axons.

Spinal cord regions (Superior to Inferior)

1. Cervical spinal nerves, 2. Thoracic spinal nerves, 3. Lumbar spinal nerves, 4. Sacral spinal nerves.

Cerebronspinal fluid

Fluid found in the central canal and subarachnoid space that acts as a shock absorber and a medium for the diffusion of dissolved gases, nutrients, chemical messengers, and wastes.

Cervical enlargement

The region of the spinal cord that supplies nerves to the shoulder and upper limbs.

Lumbosacral enlargement

The region of the spinal cord that innervates structures of the pelvis and lower limbs.

Dorsal root ganglia

Structures containing the cell bodies of sensory neurons; also known as posterior root ganglia.

Dorsal roots

Structures that bring sensory information into the spinal cord.

Ventral roots

Structures containing the axons of motor neurons that extend into the periphery to control somatic and visceral effectors; also known as anterior roots.

Rami communicantes

Axon bundles that link the spinal nerves with the ganglia of the sympathetic chain to help carry sensory and/or motor information.

Gray ramus communications

Structures containing unmyelinated fibers that innervate glands and smooth muscles in the body wall or limbs.

Mixed nerves

Nerves that contain both afferent (sensory) and efferent (motor) fibers.

Meningitis

Inflammation of the meningeal membrane.

Horns

Organized areas of spinal cord grey matter.

Sensory nuclei

Functional groups in the spinal cord that receive and relay sensory information from peripheral receptors.

Motor nuclei

Functional groups in the spinal cord that issue motor commands to peripheral effectors.

Columns

Organized areas of spinal cord white matter.

Ascending tracts

Tracts in the CNS that carry sensory information toward the brain.

Descending tracts

Tracts in the CNS that convey motor commands downward to the spinal cord.

Epineurium

The outer layer of a typical peripheral nerve consisting of a dense network of collagen fibers.

Perinerium

The middle layer of a peripheral nerve that extends inward from the epineurium.

Endoneurium

The innermost layer of a peripheral nerve that extends from the perinerium and surrounds individual axons.

Dermatome

The specific bilateral region of the skin surface monitored by a single pair of spinal nerves.

Nerve plexus

A complex interwoven network of nerves.

The four nerve plexuses

1. Cervical plexus, 2. Brachial plexus, 3. Lumbar plexus, 4. Sacral plexus.

Phrenic nerves

Nerves of the cervical plexus that supply the diaphragm; damage to these nerves leads to the cessation of breathing.

Sciatic nerve

A major nerve that belongs to the lumbar and sacral plexuses.

Neuronal pools

Functional groups of interneurons organized within the CNS.

Divergence

A neural circuit for spreading stimulation to multiple neurons or neuronal pools in the CNS.

Convergence

A neural circuit for providing input to a single neuron from multiple sources.

Serial Processing

A neural circuit in which neurons or pools work sequentially.

Parallel Processing

A neural circuit in which neurons or pools process the same information simultaneously.

Reverberation

A positive feedback neural circuit.

Neural reflex

A process where sensory fibers deliver information from peripheral receptors to an integration center in the CNS and motor fibers carry motor commands to peripheral effectors.

Innate reflexes

Reflexes that result from the connections that form between neurons during evelo[men.

Acquired reflex

Reflexes that are learned motor patterns.

Monosynaptic reflex

The simplest reflex arc where the sensory afferent neuron synapses directly on the motor efferent neuron; an example is the patellar reflex.

Polysynaptic reflex

A reflex in which interneurons are interposed between the sensory fiber and the motor neurons; examples include withdrawal and crossed extensor reflexes.

Ipsilateral reflex arcs

Reflex arcs where the sensory stimulus and the motor response occur on the same side of the body.

Contralateral reflux arx

A reflex arc where the motor response occurs on the side opposite the stimulus, such as the crossed extensor reflex.

Plantar reflex

A reflex in adults where stroking the lateral sole of the foot produces a curling of the toes.

Babinski reflux

A reflex in infants where stroking the lateral sole of the foot produces a fanning of the toes.

Carpal tunnel syndrome is caused by compression of one or more nerves that innervate the wrist. Which plexus so these nerve belong to

Brachial plexus 

The static nerve belongs to which plexus

The lumber and sarcal plexues

Which type of CNS neurons are organized into functional groups called neuronal pools

Interneurons

Name the five types of CNS organized into functional groups

1. Divergence

2. Convergence

3. Serial processing

4. Parallel processing

5. Reverberation

Step 1 of the simple neural reflex arc

Arrival of stimulus and activation receptor 

Step 2 of the simple neural reflex arc

Activation of sensory neuron

Step 3 of the simple neural reflex arc

Information processing in the CNS

Step 4 of the simple neural reflex arc

Activation of a motor neuron

Step 1 of the simple neural reflex arc

Step 5 of the simple neural reflex arc

Response by an effector