14
The left and right cervical plexuses are located deep on each side of the neck, immediately lateral to cervical vertebrae ______.
C1-C4
Cervical nerves ______ unite to form the superior trunk of the anterior rami.
C5-C6
Which are characteristic of somatosensory pathways?
Each pathway transmits information to different regions of the brain.
The anterior rami of spinal nerves ______ are called intercostal nerves because they travel in the intercostal space sandwiched between ______.
T1-T11; two adjacent ribs
The nerves emerging from a sacral plexus innervate the ______ region, pelvis, perineum, posterior thigh, and almost all of the ______.
gluteal, leg and foot
The lumbar part of the spinal cord is closest to ______.
inferior thoracic vertebrae
Sensory nervous system pathways transmit ______.
information from somatic and special sense receptors to the central nervous system
Impulses transmitted through the direct, pyramidal, or corticospinal pathway, pass directly from upper to lower motor neurons (no ______ involved) and are responsible for ______ control of skeletal muscles.
interneurons, conscious
Each anterior root and its corresponding posterior root unite within the ______ to become a spinal nerve.
intervertebral foramen
In the spinal cord, the gray matter may be subdivided into the following components: anterior, posterior, _______ and horns, and the gray commissure
lateral
The white matter region on each lateral side of the spinal cord is the ______.
lateral funiculus
The cell bodies of ______ motor neurons are found within brainstem cranial nerve nuclei or in the anterior horn of the spinal cord.
lower
The anterior rami of spinal nerves L1-L4 form the ______ plexus.
lumbar
All upper motor neurons of the corticospinal tracts pass through the ______.
medulla oblongata
A stretch reflex is a ______ reflex that monitors and regulates skeletal muscle length.
monosynaptic
A spinal nerve contains ______ axons.
motor and sensory
The spinal nerves connect the central nervous system to ______ and receptors.
muscles and glands
Each brachial plexus innervates the ______ and the entire ______ of one side.
pectoral girdle and upper limb
The initial component of a reflex arc is a(n) ______.
receptor
Awareness of the stimulus occurs after the _______ action has been completed, in time to correct or avoid a potentially dangerous situation.
reflex
A first-order neuron synapses with a ______ neuron
second order
A second-order neuron is also known as a _______ neuron.
secondary
The posterior rami of spinal nerves tend to follow a ______ pattern as they innervate the deep muscles and skin of the neck and back.
segmental
The spinal cord and its attached spinal nerves are a pathway for ______ impulses.
sensory and motor
The spinal cord in an adult is ______ than the vertebral canal that houses it.
shorter
A reflex arc is the neural wiring of a ______ reflex.
single
Pathways that transmit information from internal organs to the brain are called ______, whereas pathways that transmit information from proprioceptors and the body wall are called _______
somatosensory or somatic
Stretch in a muscle is monitored by a stretch receptor called a muscle ______.
spindle
An impulse from a lower motor neuron ______ a skeletal muscle.
stimulates or excites
A third-order neuron is also known as a _____ neuron.
tertiary
There are five roots of anterior rami that unite to form the superior, middle, and inferior ______ in the posterior triangle of the neck.
trunks
Identify the anatomical component of motor pathways.
upper and lower motor neurons
The left and right brachial plexuses are networks of nerves that supply the ______.
upper limb
The receptors in somatosensory pathways ______.
are located in the joints, skeletal muscles, and skin
Pathways that transmit sensory impulses are also called ______ pathways because the information travels from sensory receptors superiorly through the spinal cord to the brain.
ascending
The anterior corticospinal tracts innervate ______.
axial skeletal muscle
In general, we are ______ of information transmitted along somatosensory pathways to the brain, and ______ of the information transmitted along viscerosensory pathways.
conscious; unconscious or unaware
Which statements correctly describe the corticospinal tracts?
control appendicular and axial skeletal muscles
Axons of lower motor neurons of the corticobulbar tract form parts of the ______ nerves.
cranial
Impulses traveling along the corticobulbar tracts control voluntary movement of ______.
cranial and facial muscles
Spinal reflexes ______ require the involvement of the brain.
do not
The two main branches of a spinal nerve are the ventral and _______ rami.
dorsal
An impulse from an upper motor neuron ______ a lower motor neuron.
excites or inhibits
The axon of a primary neuron of a somatosensory pathway ______.
extends to the spinal cord or brainstem
The left and right cervical plexuses are formed primarily by the anterior rami of spinal nerves ______.
C1-C4
From the list below, identify the type(s) of sensory information transmitted along the spinocerebellar pathway.
-Proprioceptive, limb position -Proprioceptive, body movements
There are ______ pairs of spinal nerves.
31
A typical adult spinal cord ranges between ______ centimeters (cm) in length.
41-45
The spinal cord extends inferiorly from the brain through the foramen magnum, then through the vertebral canal, and ends at the level of the ______ vertebra.
L1
Reflexes are rapid, automatic, involuntary reactions of ______ to a stimulus.
Muscles or glands
An ______ reflex is one that is developed after birth.
acquired
The lumbar plexus is subdivided into a(n) ______ division and a(n) ______ division.
anterior and posterior
A nerve plexus is a network of interweaving ______ of spinal nerves.
anterior rami
The left and right sacral plexuses are formed from the ______ rami of spinal nerves ______ and are located immediately inferior to the lumbar plexuses
anterior, L4-S4
Spinal nerve T12 is called a subcostal nerve because it arises ______ the ribs.
below
The components of the ______ plexus extend laterally from the neck, pass superior to the first rib, and then continue into the axilla.
brachial
A third-order neuron ______.
carries the signal the rest of the way to the sensory region of the cerebral cortex
The gray matter in the spinal cord is ______ located, and its shape resembles a letter H or a ______.
centrally; butterfly
Cell bodies of upper motor neurons are located in the ______.
cerebral cortex
A third-order neuron extends from the secondary neuron to the ______.
cerebrum
Identify the characteristic of the anterior corticospinal tracts.
decussate in spinal cord
The spinal cord is partitioned into a ______ gray matter region and a ______ white matter region.
deep and superficial
The gray matter of the spinal cord is dominated by the ______ and ______ of neurons.
dendrites and cell bodies
Motor pathways are ______ pathways.
descending
A first-order neuron ______.
detects a stimulus and transmits a signal to the spinal cord or brainstem
Primary motor neurons of the ______ motor pathway originating in the primary motor cortex, whereas primary motor neurons of the ______ motor pathway originate in the brainstem.
direct and indirect
A posterior funiculus lies between the ______ gray horns on the posterior side of the cord and the posterior median sulcus.
posterior
In the spinocerebellar pathway, sensory information travels to the cerebellum along ______ neurons.
primary and secondary
After leaving the intervertebral foramen, a typical spinal nerve almost immediately splits into branches, termed ______.
rami
Primary motor neurons of the direct motor pathway issue impulses for ______ control of skeletal muscles; primary motor neurons of the indirect motor pathway issue impulses for ______ control of skeletal muscles.
voluntary and involuntary