Chapter 14: The Nervous System: The Spinal Cord and Spinal Nerves

The gray and white rami from T1 to L2, which allow information exchange between the spinal nerves and the autonomic ganglia are collectively called the:

Rami communicantes

From medial to lateral, brachial plexus structures are organized as which of the following:

Roots-Trunks-Divisions-Cords-Nerves

Activation of a motor neuron during the processing of a reflex action:

Carries the nerve impulse to the peripheral effector organs

The H-shaped mass in the center of the spinal cord is dominated by:

Cell bodies of neurons and glial cells

The anterior horns are the largest in the _______ regions:

Cervical and lumbar

The rhomboids (major and minor) are innervated by which of the following:

Cervical plexus nerves

The largest nerve in the body that is formed from L4-S3 is the:

Sciatic Nerve

Distally, the connective tissue of the ___________ is continuous with the connective tissue sheath around each spinal nerve:

Spinal dura mater

The "rami communicantes" exist for spinal nerves:

T1-L2; a white ramus and a gray ramus which collectively makes up the rami communicantes

Both the sensory and motor components of the spinal cord have a definite regional organization:

TRUE

Spinal nerves caudal to the first thoracic vertebra take their names form the vertebra immediately preceding them:

TRUE

Stretch reflexes provide automatic regulation of skeletal muscle length:

TRUE

The cervical enlargement supplies nerves to the pectoral girdle and upper limbs:

TRUE

The spinal cord continues to enlarge and elongate until an individual is approximately four years old:

TRUE

The gray matter of the spinal cord is organized into anterior, posterior, and lateral:

horns

Inferior to the __________, the spinal cord tapers to the conus medullaris:

lumbosacral enlargement

Sites where information regarding reflexes is processed include the spinal cord and the:

Brain

Polysynaptic reflex arcs differ from monosynaptic reflex arcs in that the former have ___________, which are not present in the latter:

An interneuron or interneurons

Motor patterns that are learned, like walking, are called ________ reflexes:

Acquried

Activation of a sensory neuron results in the conduction of action potentials into the spinal cord along a(n):

Afferent fiber

The body surface region monitored by a specific pair of spinal nerves is called (a):

Dermatome; these are clinically significant because damage to either a spinal nerve or dorsal root ganglion will produce a characteristic loss of sensation in specific areas of the skin.

Motor fibers travel in the ____________ of the spinal cord:

Descending tracts

Every spinal cord segment is associated with a pair of ___________, which contain the cell bodies of sensory neurons:

Dorsal root ganglia

Which of the following is defined as the tough, fibrous sheath that forms the outermost layer of a peripheral nerve:

Epineurium

The arachnoid mater is the outermost covering of the spinal cord and brain:

FALSE

The gray matter of the spinal cord can be divided into columns, or funiculi:

FALSE

The ventral ramus of each spinal nerve receives motor information from a specific segment of the skin and muscles of the neck and back:

FALSE

The brachial plexus is composed of cutaneous and muscular branches of the ventral rami of spinal nerves C1-C4:

FALSE; C5-T1

The connective tissue layers of the spinal dura mater continue from the inferior tip of the conus medullaris as the filum terminale:

FALSE; from the apex

The short head of the biceps femoris and the tibialis anterior muscles are innervated by the:

Fibular nerve

Spinal reflexes:

Include both monosynaptic and polysynaptic reflexes

The term for a reflex that is genetically determined is a(n) ___________ reflex:

Innate

The spinal nerves form through the fusion of dorsal and ventral nerve roots as they pass through a(n):

Intervertebral foramen

A normal patellar reflex indicates that spinal nerves and spinal segments_________ are undamaged:

L2-L4

The nuclei in the spinal cord that contain the cell bodies of the visceral motor neurons are located in (the):

Lateral gray horns

Which of the following is a nerve of the cervical plexus:

Lesser occipital nerve

The pia mater is the:

Meninx that forms denticulate ligaments

In step 4 of a neural reflex: a(n) __________ stimulated to threshold conducts action potentials along its axons into the periphery:

Motor neuron

The blood vessels that supply the spinal cord are found in the:

Pia Mater

Select the association that is most closely matched:

Posterior gray horns- visceral sensory nuclei

The stretch reflex is an example of a ___________ reflex because it maintains the body's upright position:

Postural

The ___________ arises from the posterior cord of the brachial plexus:

Radial Nerve

Which of the following is TRUE regarding visceral reflexes:

They control the actions of smooth muscles and glands

The first branch of each spinal nerve, which communicates with an autonomic ganglion, is myelinated and is called a(n):

White ramus

The filum terminale and ventral and dorsal spinal cord roots extending distal to the conus medullaris are collectively referred to as the:

cauda equina

"Saturday night palsy" results from pressure on the back of the arm, interrupting the function of which nerve:

Radial

The middle layer of the meninges, which consists of simple squamous epithelium, is called (the):

Arachnoid Mater

Bundles of fiber known as ____________ extend from the inner surface of the arachnoid mater to the outer surface of the pia mater:

Arachnoid trabeculae

The median nerve:

Arises from both the medial and lateral cords of the brachial plexus

Brachial plexus nerves arise from one or more trunks or cords whose neurons indicate their positions relative to the:

Axillary artery

The ventral root of a spinal nerve contains:

Axons of motor neurons

The epidural space contains areolar and adipose tissue, in addition to:

Blood vessels

The ulnar nerve is found in the____________ plexus:

Brachial

The subarachnoid space is:

Filled with cerebrospinal fluid

Caudally ,the spinal dura mater blends with components of the ___________ to form the coccygeal ligament:

Filum terminale

Axons, which cross from one side to the other in the spinal cord, pass through the:

Gray commissure

The ____________ nerve, which is formed by the ventral rami of S2-S4, innervates muscles of the perineum, including the urethral sphincter muscles:

Pudendal

The ____________ of the spinal nerves is/are the portion(s) that participate(s) in the formation of nerve plexuses:

Ventral rami

Reflexes that control the actions of smooth muscles and glands are classified as ___________ reflexes:

Visceral or autonomic

The innermost layer of connective tissue fibers and isolated fibrocytes, which surrounds each axon is the:

endoneurium

The ___________ nerve of the lumbar plexus is formed by ventral rami of T12 and L1, and innervates the internal and external oblique muscles:

iliohypogastric

All of the following are TRUE of fiber tracts in the spinal cord EXCEPT:

the tracts are randomly located with respect to the type of information carried