Chapter 17
gray matter of the spinal cord
1. is subdivided into regions called horns 2. is surrounded by white matter 3. contains neuronal cell bodies
gray commissure
A narrow strip of gray matter connecting the two lateral gray masses within the spinal cord
cervical plexus
A network formed by nerve axons from the ventral rami of the first four cervical nerves and receiving gray communicating rami from the superior cervical ganglion.
lumbar plexus
A network formed by the anterior (ventral) branches of spinal nerves L1 through L4.
sacral plexus
A network formed by the anterior rami of spinal nerves L4 through S3.
brachial plexus
A network of nerve axons of the ventral rami of spinal nerves C5, C6, C7, C8, and T1. The nerves that emerge from the _____ supply the upper limb.
nerve fascicles
A small bundle or cluster of nerve cells.
epidural space
A space between the spinal dura mater and the vertebral canal, containing areolar connective tissue and a plexus of veins.
cauda equina
A tail-like array of roots of spinal nerves at the inferior end of the spinal cord
horns
An area of gray matter (anterior, lateral, or posterior) in the spinal cord.
ramus
Branch of a spinal nerve. Plural is rami.
trauma to which segment of the spinal cord will disrupt breathing to the extent that a ventilator is needed for breathing?
C1-C3
Perineurium
Connective tissue wrapping around nerve fascicles in a nerve.
An area of skin that provides sensory input to the CNS via one pair of spinal nerves or trigeminal(v) nerve is a
Dermatome
which of the following statements is false for spinal nerves?
Every pair of spinal nerves exits through the intervertebral foramina above the vertebra that has the same name and number as the nerves.
reflex
Fast response to a change (stimulus) in the internal or external environment that attempts to restore homeostasis.
Funiculus
Group of white matter tracts in the spinal cord.
lumbosacral enlargment
Inferior enlargement of the spinal cord that extends from the ninth to the twelfth thoracic vertebra.
The spinal cord in the adult normally extends to which vertebral level?
L1-L2
quadriplegia
Paralysis of four limbs: two upper and two lower.
hemiplegia
Paralysis of the upper limb, trunk, and lower limb on one side of the body.
cervical enlargement
Superior enlargement of the spinal cord that extends from the fourth cervical vertebra to the first thoracic vertebra.
the posterior root of which spinal nerve supplies the ulnar/medial region of the forearm?
T1
dura mater
The most superficial of the three spinal meninges is a thick strong layer composed of dense irregular connective tissue called the dura mater
Epineurium
The superficial connective tissue covering around an entire nerve.
pia mater
This is the innermost meninx, a thin transparent epithelioid connective tissue layer that adheres to the surface of the spinal cord and brain. It consists of thin squamous to cuboidal cells within interlacing bundles of collagen fibers and some fine elastic fibers.
arachnoid mater
This layer, the middle of the meningeal membranes, is a thin, avascular covering comprised of an epithelioid arrangement of cells and thin, loose arrays of collagen. It's spider's-web arrangement of delicate, cellular-covered collagen fibers and some elastic fibers
meninges
Three membranes covering the brain and spinal cord, called the dura mater, arachnoid mater, and pia mater.
plexus
a network of nerves, veins, or lymphatic vessels
which of the following is False regarding the sciatic nerve
arises from the lumbar plexus
Why are spinal nerves classified as mixed nerves?
because they contain both motor and sensory neurons
in adult patients, a spinal tab to withdraw cerebrospinal fluid for diagnostic purposes is done at which of the following locations?
between L3 and L4 or L4 and L5 vertebrae
from which plexus does the long thoracic nerve arise?
brachial
from which plexus does the ulnar nerve arise?
brachial
the superior enlargement of the spinal cord is the
cervical enlargement
what is the best description of the epidural space?
contains a protective cushion of fat and connective tissue
which of the following structures help to anchor the spinal cord and protect it against sudden displacement?
denticulate ligaments and filum terminale
the coverings of a spinal nerve from the most superficial to deep include
epineurium, perineurium, endoneurium
which of the following statements is false for spinal nerves?
every pair of the spinal nerves exits through intervertebral foramina above the vertebra that has the same name and number as the nerves
which structures protect the spinal cord against sudden displacement that could result in shock?
extensions of the pia mater
select the muscle(s) served by the femoral nerve
extensor muscles of knee joint
select the muscle(s) served by the femoral nerve.
extensor muscles of knee joint
All segments of the spinal cord contain lateral, posterior (dorsal), and anterior (ventral) gray horns.
false
the anterior median fissure of the spinal cord is shallower and narrower than the posterior median sulcus
false
the pia mater that extends from the conus medullaris to the coccyx is the
filum terminale
the central canal of the spinal cord is located in the center of the
gray commissure
the central of the spinal cord is located in the center of the
gray commissure
the most common cause of spinal nerve root damage is
herniated intervertebral disc
Cell bodies of motor neurons that supply smooth muscle, cardiac muscle, or glands via the autonomic nervous system can be found in the
lateral gray horns
cell bodies of motor neurons that supply smooth muscle, cardiac muscle, or glands via autonomic nervous system can be found in the
lateral gray horns
which of the following is NOT a branch of the spinal nerve?
lateral ramus
From which plexus does the femoral nerve arise?
lumbar
The roots of which spinal nerves make up the cauda equina?
lumbar, sacral and coccygeal
the adult spinal cord extends from the
medulla oblongata inferiorly to the superior border of the second lumbar vertebra
what is the best description of the dura mater?
meninx closest to the bone of the vertebral column
Interneurons
neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
which of the following is NOT a correct description of the brachial plexus?
on the neck alongside the first four cervical vertebrae
paraplegia
paralysis of both lower limbs
Which nerve from the cervical plexus causes contraction of the diaphragm?
phrenic
which spinal meninx is deep to the subarachnoid space?
pia mater
a network of axons that form on both sides of the body by joining with axons from anterior rami of adjacent nerves is a
plexus
which of the following contains sensory information ONLY?
posterior ( dorsal ) roots
which of the following contain cell bodies of interneurons?
posterior dorsal gray horns
which of the following contains sensory information only?
posterior( dorsal ) root
Almost all spinal reflexes are ______________ in their function.
protective
from which plexus does pudendal nerve arise?
sacral
which of the following nerves is NOT from the brachial plexus?
sciatic
which of the following could serve as an effector for somatic reflex?
skeletal muscle
which of the following could serve as an effector for somatic reflexes?
skeletal muscle
these structures allow input from sensory receptors and output to muscles and glands to communicate to and from the spinal cord. what are they called?
spinal nerves
spinal nerves T2-T12 differ from all other spinal nerves in that
the anterior ( ventral ) rami do not contribute to a plexus
which of the following statements is true?
the arachnoid mater and Pia mater are often referred to collectively as the leptomeninges and dura mater is the most superficial of the three spinal meninges.
which of the following is correct about the organization of the spinal nerves
there are 31 pairs of the spinal nerves and 8 pairs of cervical nerves
lateral gray horns are present in segments of the which region(s) of the spinal cord?
thoracic, lumbar, midsacral
lateral gray horns are present in segments of the which regions of the spinal cord?
thoracic, lumbar, midsacral
The sciatic nerve is actually made of two nerves bound together by a common sheath of connective tissue. which two nerves make up the sciatic nerve?
tibial and common fibular
select the structure(s) served by the radial nerve
triceps brachii
subarachnoid space
which contains the shock-absorbing cerebrospinal fluid
