Spinal Cord, Spinal Nerves, Reflexes
The_______mater is just below (deep to) the dura mater.
Arachnoid
What is the structure between the arrows
Fascicle
Which meninx forms the terminal filum?
Pia mater
Which viral disease results in the destruction of motor neurons?
Poliomyelitis
The bundle of nerves inferior to the medullary cone of the spinal cord is called the
cauda equina
A_______nerve fiber innervates widespread organs such as muscles, skin, glands, viscera, and blood vessels.
general
__________ fibers are nerve fibers that innervate more localized organs in the head (eyes, ears, olfactory and taste receptors, etc.).
special
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
Each spinal cord segment gives rise to a pair of spinal nerves. How many pairs of spinal nerves are typically present in an adult?
31
What is gray commissure of spinal cord?
A band of gray matter connecting the gray matter of the left side with the gray matter of the right side
Where does the spinal cord arise from the medulla oblongata?
At the foramen magnum
External to the neurilemma of a nerve fiber is the layer of loose connective tissue that surrounds a nerve fiber called a(n):
Endoneurium
What is the loose connective tissue surrounding an individual nerve fiber called?
Endoneurium
The lateral horns of the spinal cord contain somas of which neurons?
Sympathetic Motor
How many neurons are found in a descending tract?
Two
In descending pathways, which motor neurons have their somas in the cerebral cortex or brainstem?
Upper
______ fibers are nerve fibers that innervate blood vessels, glands, and internal organs.
Visceral
The ———median fissure is a longitudinal groove on the ventral surface of the spinal cord.
anterior
the__________horns of the spinal cord contain the cell bodies of outgoing somatic motor neurons.
anterior
The__________space is located between the vertebrae and the dural sheath around the spinal cord.
epidural
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
The ______ enlargement is the area of spinal cord that gives rise to the nerves of the lower limbs and pelvis.
lumbosacral
The ______ is the tapered end of the spinal cord.
medullary cone
A ______ nerve is a peripheral nerve carrying nerve signals to the CNS.
sensory
What is the cauda equina?
A bundle of nerve roots occupying the vertebral canal from L2 to S5
What is a nerve?
A cord of nerve fiber bundles bound together by connective tissue
Which describes a mixed nerve?
A nerve containing both sensory and motor nerve fibers
What is a region of the spinal cord supplied by a pair of spinal nerves called?
A segment
What is a fasciculus in the spinal cord?
A tract of nerve fibers within a funiculus
In which disease does sclerosis of the lateral spinal cord occur, with destruction of motor neurons?
Amyotrophic lateral sclerosis
Which horns of the spinal cord contain the cell bodies of outgoing somatic motor neurons?
Anterior
Which spinal cord areas are composed of gray matter?
Anterior horn Gray commissure Posterior horn
Which meninx is just below (deep to) the dura mater?
Arachnoid mater
Within the spinal cord, which tracts carry information up to the brain?
Ascending
A nerve fiber refers to which part of a neuron?
Axon
Where is the epidural space around the spinal cord?
Between the vertebral bones and the dural sheath
What is the white matter of the spinal cord?
Bundles of myelinated and unmyelinated axons found superficial to the gray matter
In the spinal cord, what is the space within the gray commissure that contains CSF?
Central canal
Functions of the spinal cord include which of the following?
Conduction, locomotion, reflexes
The spinal cord contains ascending and descending nerve fibers that send information between the CNS and the periphery. This illustrates which function of the spinal cord?
Conduction.
Which tract will have its origin and destination of opposite sides of the body?
Contralateral
What factor accounts for the fact that the right side of the brain communicates with the left side of the body, and vice versa?
Decussation
What is the epineurium composed of?
Dense irregular connective tissue
What is the dural sheath around the spinal cord made of?
Dura mater
Place the meninges in order from superficial to deep. Instructions
Dura mater Arachnoid mater Pia mater
Pain during childbirth is often managed by injecting an anesthetic into which space?
Epidural
Which connective tissue layer is indicated by the arrow?
Epineurium
Which is composed of dense irregular connective tissue?
Epineurium
How are the spinal cord regions named?
For the level of vertebral column from which its spinal nerves emerge
What is a cluster of neuron cell bodies located outside of the CNS called?
Ganglion
What is the site of synaptic integration in the spinal cord?
Gray matter
Which nerve tracts do not decussate?
Ipsilateral
In an adult, the spinal cord ends at which vertebra?
L1
In descending tracts, which motor neuron innervates the target organ?
Lower
The anterior horns of the spinal cord contain somas of somatic ______ neurons.
Motor
The poliovirus destroys which neurons in the brainstem and anterior horn of the spinal cord?
Motor
Within the spinal cord, what type of information do the descending tracts carry?
Motor
Which are purely sensory nerves?
Olfactory and optic nerves
What are two examples of nerves that carry only sensory information?
Optic and Olfactory nerve
Which connective tissue layer is indicated by the arrow?
Perineurium
What are the three funiculi of white matter found in the spinal cord?
Posterior funiculus Ventral funiculus Lateral funiculus
Which is a somatic stimulus of a somatic reflex?
Pressure Stretch Temperature Touch Pain
In the PNS, the__________cells form a neurilemma and the myelin sheath around an axon.
Schwann
Nerve fibers of peripheral nerves are encased in which cells?
Schwann
Which pathways are made up of three neurons?
Sensory
Unlike visceral fibers that innervate blood vessels, glands, and viscera, ______ nerve fibers innervate skin, skeletal muscles, bones, and joints.
Somatic
In which does cerebrospinal fluid circulate?
Subarachnoid space
In the spinal cord, where is the white matter in relation to the gray matter?
Superficial
Where is the white matter in the spinal cord?
Superficial to the gray matter
The lateral gray horns of the spinal cord are found from segment_______to segment L1 of the spinal cord.
T2
The lateral gray horns of the spinal cord are found in which segments of the spinal cord?
T2 to L1
what is the arrow pointing to?
Terminal filum
What does contralateral mean?
That two points are on opposite sides of the body.
What does ipsilateral mean?
That two points are on the same side of the body
What is the cervical enlargement of the spinal cord?
The area of the spinal cord that gives rise to the nerves of the upper limbs
What is the posterior median sulcus of the spinal cord?
The longitudinal groove on the dorsal surface of the spinal cord
What is the subarachnoid space?
The space between the arachnoid mater and pia mater
Identify the regions of the spinal cord.
Thoracic Cervical Lumbar Sacral
How many neurons are typically found in an ascending pathway between the receptor and the brain?
Three
What is a bundle of nerve fibers within the white matter of the spinal cord called?
Tract
_________matter is composed of myelinated and unmyelinated axons and is superficial to the gray matter
White
A(n) ______ fiber is a nerve fiber carrying nerve signals toward the central nervous system.
afferent
The middle layer of the meninges is the ______ mater.
arachnoid
In the spinal cord_______the canal is lined with ependymal cells and contains cerebrospinal fluid.
central
The ________ Enlargements of the spinal cord gives rise to the nerves of the upper limbs.
cervical
spinal cord regions in order from superior to inferior. Instructions
cervical thoracic lumbar sacrum
The left and right sides of the gray matter in the spinal cord are connected by the gray
commissure
The end of the spinal cord indicated by the arrow labeled A in the figure is the medullary_____________.
cone
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
A ______ is a tract of nerve fibers within a column of the spinal cord.
fasciculus
The__________matter of the spinal cord contains the synapses and therefore is the site of synaptic integration.
gray
The ______ are a series of fibrous connective tissue membranes covering the central nervous system.
meninges
A ______ nerve is a nerve containing only fibers carrying outgoing nerve signals from the CNS.
motor
The ______ mater is the meningeal layer that is closely associated with the contours of the spinal cord.
pia
Which layer of the meninges is the most delicate and is composed of one or two layers of squamous to cuboidal cells and delicate collagenous and elastic fibers?
pia mater
The———median sulcus is a longitudinal groove on the dorsal surface of the spinal cord.
posterior
The cerebrospinal fluid circulates in the_________space between the meninges.
subarachnoid
The space between the arachnoid mater and pia mater is called the__________space.
subarachnoid
In the CNS, bundles of axons that make up white matter are called ______.
tracts
