Chapter 12

The _____ _____ innverages the pectoral girdle and upper limbs, with contributiosn from the ventral rami of spinal nerves C4 to T1

brachial plexus

Contains postganglonic fibers that innervate glands and smooth muscles in the body wall or limbs.

gray ramus

Ventral rami of the adjacent spinal nerves blend their fibers producing a series of compound nerve trucks called

nerve plexus

contains preganglionic and post ganglionic fibers innverating structures in the thoracic cavity

sympathetic nerve

The ______ _______ carries sensory information from the ventrolateral body surface, structures in the body wall, and limbs

ventral ramus

the axons in the relatively large ______ _______ supply the ventrolateral body surface, structures in the body wall, and the limbs

ventral ramus

Contains somatic and visceral sensory nuclei

Posterior gray horn

A shallow longitudianl groove on the posterior surface of the spinal cord

Posterior median sulcus

Lies between the posterior gray horns and the posterior median sulcus

Posterior white column

Recieve and relay sensory information from peripheral receptors

Sensory nuclei

Contains somatic motor nuclei

Anterior gray horn

Lies between the anterior gray horns and the anterior median fissure.

Anterior white column

Interconnects the anterior white colums. Axons cross from one side of the spinal card to the other.

Anterior white commissure

The menigelal layer.

Arachnoid

Carry sensory information toward the brain.

Ascending tracts

Consists of a meshwork of elastic and collagent fibers that is firmly bound to the underlying neural tissue

Pia mater

The dorsal and ventral roots of spinal segments L2 to S5, extending inferiorly. Resembles a "horse's tail"

Cauda equina

A shock absorber and a diffusion medium for idssolved gases, nutrients, chemical messengers, and waste products.

Cerebrospinal fluid

Supplies nerves to the shoulder and upper limbs

Cervical enlargement

Located on each side of the spinal cord and can be divided into three regions

Columns

Present in the thoracic and superior lumbar segments of the spinal cord. Contain the axons of sympathetic neurons.

Communicating rami

Tapered, conical portion of the spinal cord inferior to the lumbar enlargment

Conus medullaris

These prevent lateral movement of the spinal cord

Denticulate ligaments

Convey motor commands to the spinal cord

Descending tracts

Innervates the muscles, joints, and skin of the back. Contains somatic motor and visceral motor fibers.

Dorsal ramus

Contains axons of the neurons whose cell bodies are in the dorsal root ganglion

Dorsal root

Contains the cell bodies of sensory neurons whose axons carry information to the spinal cord.

Dorsal root ganglion

Tough, ribrous, outermost layer covering the spinal cord

Dura mater

The innermost layer, consists of delicate connective tissues that extend from the perineurium and surround individual axons

Endoneurium

A region that contains areolar tissue, blood vessels, and a protective padding of adipose tissue

Epidural space

Outermost covering of the nerve, consists of a dense network of collagen fibers

Epineurium

A slender strand of fibrious tissue that extends from the inferior tip of the conus medullaris to the second scral vetrebra. Provides longitudinal support to the spinal cord as a component of the coccygeal ligament

Filum terminale

Contains axons that cross from one side of the cord to the other before they reach a destination in the gray matter

Gray commissures

Surrounds the narrow central canal and forms an "H" or "butterfly" shape

Gray matter

The projection of gray matter toward the outer surface of the spinal coard is called the

Horns

Includes the white matter on either side of the spinal cord, between the anterior and posterior columns

Lateral white column

Provides innervation to structures of the pelvis and lower limbs

Lumbar enlargement

Issue motor commans to peripheral effectors

Motor nuclei

The cell bodies of the neruons in the gray matter of the spinal cord are organized into functional groups called

Nuclei

The middle layer, extended inward from the epineurium.

Perineurium

A series of specialized membranes surrounding the spinal cord provides the necessary stabilty and shock absorption.

Spinal meninges

Contains the axons of sensory and motor neurons. The sensory fibers enter the CNS through the dorsal root. The motor fibers emerge from the CNS within the ventral root.

Spinal nerve

Extends between the arachnoid membrane and the outer surface of the pia matter

Subrachnoid space

This is responsible for the the "fight or flight" response.

Sympathetic division

Contains large numbers of myelinated and unmyelinated axons

White matter

A bundle of axons in the CNS that is relatively uniform with respect to diameter, myelination, and conduction of speed

Tracts

Innervates structure in the lateral and anterior trunks as well as the limbs

Ventral ramus

Contains the axons of motor neurons that extend into the periphery to control somatic and visceral effectors

Ventral root

the first branch from the spinal nerve. Carries viscerlal motor fibers to a nearby sympathic ganglion.

White ramus

Specific bilateral region of the skin surface monitored by a single pair of spinal nerves

dermatome

Contains somatic motor and visceral motor fibers that innervate the skin and skeletal mucsles of the back

dorsal ramus

The ____ ____ carries sensory information from the skin and skeletal muscles of the back

dorsal ramus

The _____ ______ of each spinal nerve carries sensory information to the spinal card

dorsal root

Spinal menings layers

dura mater, arachnoid mater, pia mater

communicating branches

rami communicantes

each ramus of a ____ _____ provides motor and sensory innervation to a specific region

spinal nerve

The _____ ______ carries information from the visceral organs

sympathetic nerve