Chapter 13

there are ___ pairs of spinal nerves

31

the ___ horns of the spinal cord contain the cell bodies of outgoing somatic motor neurons

anterior

the ___ median fissure is a longitudinal groove on the ventral surface on the spinal cord

anterior

where does the spinal cord arise from the medulla oblongata? -at the medullary cone -at the cervical enlargement -at the foramen magnum

at the foramen magnum

the bundle of nerves inferior to the medullary cone of the spinal cord is called the ___ ___

cauda equina

in the spinal cord, the ___ canal is lined with ependymal cells and contains cerebrospinal fluid

central

in the spinal cord, the ____ canal is lined with ependymal cells and contains cerebrospinal fluid

central

because it contains ascending and descending nerve tracts, a function of the spinal cord is the ____ of nerve signals between the CNS and the periphery of the body

conduction

which tract will have its origin and destination of opposite sides of the body? -ipsilateral -contralateral

contralateral

a reflex in which a contralateral extensor muscle is contracted is called a ___ ____ reflex

crossed extension

because the nerve tracts of the spinal cord undergo ____, the right side of the brain communicates with the left side of the body, and vice versa

decussation

with the spinal cord, which tracts carry motor signals down from the brain? -association -descending -ascending -commissural

descending

the dural sheath around the spinal cord is formed from the ___ mater

dura

the nerve signal for the reflex response is carried to the effector by a ___ nerve fiber

efferent

____ fibers are working muscle fibers outside a muscle spindle

extrafusal

T/F: a reflex involving one or more interneurons is a monosynaptic reflex

false

T/F: reflex pathways always involve the cerebral cortex

false

a quick contraction of flexor muscles in response to a painful stimulus is called a ___ reflex

flexor

the ___ matter of the CNS is where the neuron cell bodies, dendrites, and synapses are found

gray

____ muscle fibers are modified muscle fibers within a muscle spindle

intrafusal

the ___ are a series of fibrous connective tissue membranes covering the central nervous system

meninges

the anterior horns of the spinal cord contain somas of somatic ____ neurons

motor

which meninx is closely associated with the contours of the spinal cord? -arachnoid mater -pia mater -dura mater

pia mater

the ___ median sulcus is a longitudinal groove on the dorsal surface of the spinal cord

posterior

what is the neural pathway that mediates a reflex called? -reflex arc -reflex transmission -reflex path

reflex arc

within the spinal cord, which tracts carry information up to the brian? -sensory -motor -association -efferent

sensory

____ reflexes use receptors located in the skin, muscle, and tendons

somatic

the space between the arachnoid mater and pia mater is called the ____ space

subarachnoid

what is a bundle of nerve fibers within the white matter of the spinal cord called? -column -horn -commissure -tract

tract

T/F: muscle spindles sense changes in muscle length and are therefore proprioceptors

true

how many neurons are found in a descending tract? -three -four -two -one

two

in descending pathways, which motor neurons have their somas in the cerebral cortex or brainstem? -lower -upper -middle

upper

___ matter is composed of myelinated and unmyelinated axons and is superficial to the gray matter of the spinal cord

white