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