unit3 - spinal cord & spinal nerves
Define somatic nerve fibers.
Nerve fibers that innervate skin, skeletal muscles, bones, and joints
In Amyotropic Lateral Sclerosis excess glutamate leads to motor neuron destruction with subsequent scarring (sclerosis) of the _____ regions of the spinal cord.
lateral
Neurons of the sympathetic nervous system are found in _____ horns of the spinal cord
lateral
The branch of the spinal nerve that innervates the meninges as well as the vertebrae and spinal ligaments is the _____ branch.
meningeal
A series of fibrous connective tissue membranes covering the central nervous system is referred to as the _____.
meninges
A nerve containing both sensory and motor nerve fibers is called a _____ nerve.
mixed
Based on the presence of both efferent and afferent fibers, spinal nerves are classified as which of the following?
mixed
The simplest reflex arc is ______.
monosynaptic
The anterior horns of the spinal cord contain somas of somatic _____ neurons.
motor
The anterior root of a spinal nerve contain axons of which neurons?
motor
he anterior root of a spinal nerve contain axons of which neurons?
motor
Poliomyelitis is caused by a virus that destroys ______.
motor neurons in the brainstem and anterior horn of the spinal cord
Efferent fibers carry _______ signals ______ the CNS
motor, from
A cordlike organ within the peripheral nervous system composed of numerous nerve fibers (fascicles) bound together by connective tissue is referred to as a _____.
nerve
A nerve is comprised of _____.
numerous fascicles bound together by connective tissue
The connective tissue layer surrounding a nerve fascicle is called the _____.
perineurium
Inferior to the medullary cone, the terminal filum is formed by the _____ mater.
pia
Innervation to the local muscles, joints, and skin of the back is provided by the ______ ramus of a spinal nerve.
posterior
The spinal nerve roots carrying afferent (sensory) nerve signal are the _____ roots.
posterior
The distal branches of a spinal nerve include which of the following?
posterior and anterior rami
Which spinal cord areas are composed of gray matter? Select all that apply.
posterior horn, lateral horn, anterior horn
Moving peripherally from the spinal cord, the anterior and posterior _____ form the spinal nerve
root/roots
Moving peripherally out from the spinal cord, spinal nerve _____ are the closest structures to the spinal cord.
rootlets
What structure of the spinal nerve is situated closest to the spinal cord?
rootlets
Nerve plexuses arise from spinal nerves in which regions? Select all that apply.
sacral, cervical, lumbar
Cell bodies found within posterior root ganglia are those of _______ neurons.
sensory
Afferent nerve fibers carry ______ signals ______ the CNS.
sensory, to
Posterior roots which enter the posterior horn of the spinal cord convey _____ fibers.
sensory/afferent
Nerve fibers that innervate skin, skeletal muscles, bones, and joints are classified as _____.
somatic
Nerve fibers that innervate more localized organs in the head (eyes, ears, olfactory and taste receptors, etc.) are classified as _____ fibers.
special
The cerebrospinal fluid circulates in the _____ space between the meninges.
subarachnoid
In which does cerebrospinal fluid circulate?
subarachnoid space
The lateral horns of the spinal cord contain neurons of the ______ nervous system.
sympathetic
Monosynaptic reflex arcs are rapid because ______.
there is only one synapse for delay
Nerve fibers that innervate blood vessels, glands, and internal organs are classified as _____.
visceral
An abundance of myelinated axons arranged in tracts located superficial to the gray matter of the spinal cord makes up the _____ matter
white
An abundance of myelinated axons arranged in tracts makes up the _______ matter of the spinal cord.
white
A cluster of neuron cell bodies outside of the CNS, i.e. in the periphery is referred to as a _____.
ganglion
Nerve fibers that innervate widespread organs such as muscles, skin, glands, viscera, and blood vessels are classified as _____ fibers.
general
Neuron cell bodies, dendrites, and synapses are found in the CNS within the _____ matter.
gray
All spinal nerves except C1 pass through which structure to emerge from the vertebral column?
intervertebral foramen
In Amyotrophic Lateral Sclerosis, motor neurons are destroyed with subsequent scarring (sclerosis) of the ______ regions of the spinal cord.
lateral
Into what cavity is an epidural anesthetic delivered?
The space between the vertebral bones and dural sheath
What are the regions of the spinal cord?
Thoracic, lumbar, cervical, sacral
A motor nerve is defined as ______.
a nerve containing only fibers carrying outgoing nerve signals from the CNS
Nerve fibers carrying signals toward the central nervous system from receptors are classified as _____.
afferent
Innervation to the anterior and lateral skin and muscles of the trunk and limbs is provided by the ______ ramus of of a spinal nerve.
anterior
The intercostal nerves arise from the ______ rami of the ______ spinal nerves.
anterior, thoracic
The neural pathway that mediates a reflex is called a reflex _____.
arc
Somatosensory nerves carry signals from ______.
bones, muscle and skin
Gray matter is found in the _____.
brain and spinal cord
White matter is found in the ______.
brain and spinal cord
The bundle of nerve roots occupying the vertebral canal from L2 to S5 is referred to as the _____ _____.
cauda equina
The central canal contains ______.
cerebrospinal fluid
A sensory nerve is defined as ______.
containing only fibers carrying incoming nerve signals to the CNS
The epineurium is composed of ______.
dense irregular connective tissue
An area of skin supplied by a single spinal nerve is referred to as a ______.
dermatome
Nerve fibers carrying nerve signals from the CNS to effectors are classified as _____.
efferent
Anterior roots of the spinal cord contain axons of ______ neurons.
efferent, motor, somatic
External to the neurilemma of a nerve fiber is the layer of loose connective tissue that surrounds a nerve fiber called the
endoneurium
Pain during childbirth is often managed by injecting an anesthetic into which space?
epidural space
Identify the connective tissue layer that surrounds the entire nerve.
epineurium
The nerve fiber covering made of dense irregular connective tissue which protects the nerve from stretching and injury is the ______.
epineurium
True or false: Reflexes are spontaneous actions.
false
Within a nerve, nerve fibers are gathered into bundles called _____.
fassicles
The poliomyelitis virus is spread through ______.
fecal contamination of water
Which are considered a distal branch of a spinal nerve? Choose all that apply.
-Posterior ramus -Anterior ramus
A mixed nerve is defined as ______. Select all that apply.
-a nerve that conducts signals in two directions. -a nerve containing both sensory and motor nerve fibers -a nerve containing both afferent and efferent nerve fibers.
Identify characteristics of a reflex. Select all that apply.
-involuntary -responses to sensory input -quick
Somatosensory signals are sent in response to changes in which of the following stimuli? Select all that apply.
-pain and pressue -touch, heat, stretch
Place the meninges in order from superficial to deep.
1. Dura mater 2. Arachnoid mater 3. Pia meter
Adult humans have ______ pairs of spinal nerves arising from the spinal cord.
31
What is the cauda equina?
A bundle of nerve roots occupying the vertebral canal from L2 to S5
Which are made of gray matter?
Anterior, posterior and lateral horns
Functions of the spinal cord include which of the following?
Conduction, locomotion, reflexes
What are meninges?
Fibrous connective tissue membranes covering the central nervous system
The first cervical spinal nerve emerges between which two structures?
Skull and vertebra C1
The anterior horns of the spinal cord contain the somas of which neurons?
Somatic motor