spinal cord
What is a nerve?
A cord of nerve fiber bundles bound together by connective tissue
Which of the following describes a sensory nerve?
A nerve containing only fibers carrying incoming nerve signals to the CNS
Which are functions of the spinal cord?
Locomotion Conduction Reflexes
What do muscle spindles monitor?
Muscle length and body movements
A(n) ______ fiber is a nerve fiber carrying nerve signals toward the central nervous system.
afferent
The spinoreticular tract is found in which columns of the spinal cord?
anterior and lateral
the spinothalamic tract is found in which columns of the spinal cord?
anterior and lateral
The__________ tract carries signals for precise, finely coordinated limb movements.
corticospinal
What is the loose connective tissue surrounding an individual nerve fiber called?
endoneurium
Which is composed of dense irregular connective tissue? Multiple choice question. Perineurium Epineurium Endoneurium
epineurium
True or false: Severing a sensory nerve root will completely deaden sensation from a dermatome.
false
Which stimulus causes a muscle to reflexively contract?
increased stretch
All spinal nerves except C1 pass through a(n) foramen to emerge from the vertebral column.
intervertebral
which nerve tracts do not decussate?
ipsilateral
Which tract will have its origin and destination on the same side of the body? Which tract will have its origin and destination of opposite sides of the body?
ipsilateral; contralateral
The __________branch of the spinal nerve innervates the meninges.
meningeal
The third-order neurons of the spinoreticular tract runs from the ______ to the thalamus.
pons
The ______ roots are the spinal nerve roots that carry sensory nerve signals.
posterior
The cuneate fasciculus is located in the ______ column of the spinal cord.
posterior
Which are considered a distal branch of a spinal nerve?
posterior and anterior ramus
What type of signal does the spinocerebellar tract carry?
proprioception
In the spinothalamic tract, the ______ -order neurons decussate from the posterior horn of the spinal cord.
second
The somas of which neurons are found within the posterior root ganglion?
sensory
Unlike visceral fibers that innervate blood vessels, glands, and viscera, ______ nerve fibers innervate skin, skeletal muscles, bones, and joints.
somatic
In a sensory pathway, which neurons run from the thalamus to the sensory cerebral cortex?
third order
The number of neurons in a descending pathway is
2
How many spinal nerves are there in order from superior to inferior? Instructions
8 Cervical, 12 Thoracic, 5 Lumbar, 5 Sacral, 1 Coccygeal
what is the order of the meninges from superficial to deep?
Dura mater, arachnoid mater, pia mater
Where does the first-order neuron of the spinothalamic tracts end?
In the posterior horn at the point of entry
Which is responsible for the inhibition of antagonistic contraction during a reflex response?
Spinal cord interneurons inhibit alpha neurons to the antagonists.
Which neurons would need to be inhibited in order for reciprocal inhibition to occur?
The alpha motor neurons to the antagonistic muscle
Where does the spinal cord arise from the medulla oblongata?
at the foramen magnum
A nerve fiber refers to which part of a neuron?
axon
What is the cauda equina?
bundle of nerve roots that occupy the vertebral canal from L2 to S5
Which structure is formed from nerves C1-C5?
cervical plexus
The anterior rami of spinal nerves form which nerve plexuses?
cervical, lumbar, sacral
A reflex in which a contralateral extensor muscle is contracted is called a extension reflex.
crossed
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
What is an area of skin innervated by a spinal nerve called?
dermatome
Within the spinal cord, which tracts carry motor signals down from the brain?
descending
In a sensory pathway, the ________order neuron detects the stimulus and transmits the signal to the spinal cord or brainstem.
first
which reflex is ipsilateral?
flexor
where is the origin of sensory signals carries by the cuneate fasciculus?
from vertebra t6 and up
A is a cluster of neuron cell bodies found outside of the CNS.
ganglia
A ___________nerve fiber innervates widespread organs such as muscles, skin, glands, viscera, and blood vessels.
general
The ______ motor neurons (which are the motor neurons connecting the brainstem and spinal cord to muscle fibers) of the descending pathway innervate skeletal muscle.
lower
A nerve containing both sensory and motor nerve fibers is called a(n) nerve.
mixed
A ___________reflex arc consists of only one synapse between two neurons.
momsynaptic
The anterior root of a spinal nerve contain axons of which neurons?
motor
What are two examples of nerves that carry only sensory information?
optic, olfactory
The spinoreticular tract carries what type of signals?
pain
Within a nerve, each fascicle is wrapped in which layer?
perineurium
Place the components of a reflex arc in order.
receptor afferent nerve fiber integration center efferent nerve fiber effector.
The second-order neurons of the spinoreticular tract terminate in the _________ formation of the brainstem.
reticular
Where do the second-order neurons of the spinoreticular tract terminate?
reticular formation
Which of these structures is closest to the spinal cord?
rootlets
Moving peripherally from the spinal cord, which anterior and posterior structures form a spinal nerve?
roots
Nerve fibers of peripheral nerves are encased in which cells?
schwann
In a sensory pathway, which neurons run from the spinal cord or brainstem to the thalamus?
second
True or false: The flexor reflex uses an ipsilateral reflex arc.
true
Consider the two motor neurons that form descending pathways. The neurons called the ________motor neurons have their somas in the cerebral cortex or brainstem.
upper
What is the source of the sensory signals carried by the cuneate fasciculus?
upper limbs and chest
_________ matter is composed of myelinated and unmyelinated axons and is superficial to the gray matter of the spinal cord.
white