ch 13 spinal cord and spinal nerves

How many pairs of spinal nerves?

31

what are sensory nerves called?

afferents

what are motor nerves called?

efferents

cone-shaped end of spinal cord

conus medullaris

thread-like extension of pia mater, stabilizes spinal cord in canal

filum terminale

dorsal & ventral roots of lowest spinal nerves

caudae equinae

area of cord from which each pair of spinal nerves arises

spinal segment

shaped like a letter H or a butterfly; contains neuron cell bodies, unmyelinated axons & dendrites

gray matter

prevents injury from over stretching because muscle contracts when it is stretched

stretch reflex (patellar reflex)

controls muscle tension by causing muscle relaxation that prevents tendon damage

tendon reflex

outermost layer/toughest

dura mater

pia mater below the medullary cone

terminal filium

innermost layer, closely over lays spinal cord, delicate collagen fibers, vascular

pia mater

subarachnoid space below the medullary cone

lumbar cistern

loose mesh of collagen and elastic fibers

subarchnoid space

middle layer, simple squamous epithelium/adheres to inside of dura mater

arachnoid mater

adipose tissue, blood vessels, loose connective tissue

spidural space

Gray matter is the site of synaptic connections between neurons and neuronal integration

true

What connects the left and right sides of gray matter?

gray commissure

conducts signals from peripher to CNS

dorsal root

conducts signals from CNS to periphery

ventral root

dorsal root and ventral root join to exit

vertebral foramina

bundle of nerves on dorsal root

dorsal root ganglion

supplies muscles and joints to the spine and skin of back

posterior (dorsal) ramus

supplies meninges and vertebrae

meningeal branch

how far does the spinal cord run?

foramen magnum - L1

The spinal cord passes through the _________

foramen magnum

The conus medullaris is the tapering point at the end of the spinal cord. It is located at approximately _________

L1/L2

The tail end of the spinal cord is not “hanging loose.” It is actually anchored via the __________, which connects to the coccyx bone

filum terminale

How many plexus groups branch off the spinal cord?

4

Which of the following spinal cord regions are NOT involved with a plexus formation

thoracic

The cauda equina are nerves that branch off the spinal cord in which of the following areas?

inferior end

What is the name of the structures that hold the spinal cord in position within the vertebral foramen?

denticulate ligaments

Which of the following transmits information from the spinal cord to the extremities of the body?

ventral roots

Fasciculi are bundles of nerve tracts associated with _________

the white matter of the spinal cord

Which of the following will merge together (after branching off the spinal cord) to form a spinal nerve?

ventral and dorsal roots

The plexus groups that are formed from the branches off the spinal cord are formed from the merging of ________

one ventral ramus with another ventral ramus