Lab Exam Three: The Spinal Cord and Spinal Nerves Flashcards
Spinal cord:
a cylinder of nervous tissue
What is the extension of the spinal cord?
arises from the brainstem at the foramen magnum of the skull
The spinal passes through the […] as far as the inferior margin of the first […] (L1).
vertebral canal; lumbar vertebra
How many total spinal nerves from the spinal cord? How many within each section of the spine?
31
cervical = 8 thoracic = 12 lumbar = 5 sacrum = 5 coccygeal = 1
Where do most of these spinal nerve pair pass through?
intervertebral foramina
The cord exhibits […] on its anterior and posterior sides- the anterior […] and posterior […].
longitudinal grooves; median fissure; median sulcus
T/F: Does the spinal cord divide into the regions of the intevertebrae?
true
well minus the coccyx
In what two areas is the cord thicker?
- cervical enlargement
2. lumbar enlargement
Cervical enlargement gives rise to the nerves of the […] while the lumbar enlargement issues nerves to the […].
upper limbs; pelvic region and lower limbs
Medullary cone is also known as the …
conus medullaris
Medullary cone:
bundle of nerve roots that occupy the vertebral canal from L2 to S5
Cauda equina:
innervates the pelvic organ and lower limbs
The spinal cord and brain are enclosed in […] called […].
three fibrous connective tissue; meninges
Meninges separate the […] of the CNS from the bones of the […] and […].
soft tissue; vertebrae; skull
From superficial to deep list the meninges of the spinal cord:
- dura mater
- arachnoid mater
- pia mater
Dura mater:
tough collagenous membrane, forms dura sheath
Space between the sheath and vertebral bones is called…
epidural space
Epidural space is occupied by what?
- adipose tissue
- blood vessels
- loose connective tissue
Arachnoid mater:
simple squamous epithelium (arachnoid membrane)
The gap between the arachnoid membrane and the pia mater is called…
subarachnoid space
Subarachnoid space is filled with …
cerebrospinal fluid
Pia mater:
transparent membrane that closely follows the contours of the spinal cord
Beyond the medullary cone there is […] within the […].
terminal filum; lumbar cistern
At S2, the pia mater fuses with the […] mater to form a […].
dura; coccygeal ligament
Extensions of the pia called […] extend through the […] to the […], anchoring the cord.
denticulate ligaments; arachnoid; dura
The spinal cord consists of two kinds of nervous tissue:
- gray matter
2. white matter
Gray matter contains little […]. also […], dendrites, and […] of the axons of neurons.
myelin; somas; somas; proximal parts
Gray matter is the sight of …
synaptic contact between neurons also known as neural integration
White matter is abundant in…
myelin
White matter is composed of bundles of axons called […], that […] from one part of the CNS to another.
tracts; carry signals
What do both gray and white matter also have an abundance of?
glial cells
The central core shape of gray matter resembles what?
butterfly/H-shape at cross section
The gray matter core consists of what two surfaces?
- posterolateral surfaces of two thick posterior dorsal horns
- anterolateral surfaces with two thicker anterior ventral horns
The right and left sides of gray matter are connected by […].
gray commisure
In the middle of the gray matter’s commissure is the […], lined with […], and filled with […].
central canal; ependymal cells; CSF
Gray matter– Spinal nerve branches into a […] and […].
posterior dorsal root; anterior ventral root
Gray matter– The posterior root carries what type of fibers?
sensory nerve fibers
Gray matter– The anterior horn contains what?
large somas of the somatic motor neurons
White matter of the spinal cord […] gray matter.
surrounds
White matter consists of […] that course up and down the cord and provide avenues of […] between different levels of the […].
bundles of axons; communication; CNS
How are the bundles of axons arranged within white matter?
three pairs called columns or funiculi
List the three columns within the white matter?
- posterior dorsal column
- lateral column
- anterior ventral column
White matter– Each column consists of subdivisions called […] or […].
tracts; fasciculi
Ascending spinal tracts carry …
sensory information up the cord
Descending spinal tracts ….
conduct motor impulses down the cord
Spinal tracts can undergo […].
decussation
Decussation:
spinal tracts cross over from the left side of the body to the right (vice versa)
The left side of the brain receives sensory information from the […]. From the right side of the brain […] and […] the […] side.
right; senses; controls; left
Contrallateral:
origin and destination of a tract are on opposite sides of the body
Ipsilateral:
when a tract does not decussate, its origin and destination are on the same side of the body
Nerve:
cordlike organ composed of numerous never fibers (axons) bound together by connective tissue
Each nerve fiber is surrounded by a […] and then a thin sleeve of […] tissue call the […].
basal lamina; loose connective; endoneurium
Nerve fibers are gathered in bundles called […], each wrapped in a sheath called the […].
fascicles; perineurium
Several nerve fiber bundles (fascicles) are then bundled together and wrapped in an outer […].
epineurium
Sensory (afferent) fibers carrying signals…
from sensory receptors to the CNS
Motor (efferent) fibers carrying signals…
from the CNS to muscles and glands
T/F Most nerves are either sensory or motor.
False
most nerves are mixed conducting signals in two directions
What does a nerve resemble? a ganglion?
thread
a knot in the thread
Ganglion:
cluster of neurosomas outside the CNS
Where does a nerve exit through?
intervertebral foramen
Chickenpox is also known as…
varicella
Chickenpox:
common disease of early childhood is caused by varicella-zoster virus
**leads to itchy rash
The virus remains […] in the […].
for life; posterior root ganglia
Chickenpox– If the immune system is compromised, the virus can cause.
shingles
How does chickenpox cause singles?
virus can travel along the sensory nerve fibers by fast axonal transport
Shingles:
painful trail of skin discoloration and fluid-filled vesicles along the path of the nerve
Postherpetic neuralgia (PHN):
chronic intense pain in the site of the lesions lasting for months or even years
Vaccine for shingles:
varicella for children
zostavax for adults (60+)
Treatment for shingles:
- aspirin and steroidal ointments (pain relief)
- acyclovir (antiviral drug) can shorten the course of an episode of shingles, but only if taken within the first 2-3 days of outbreak
Are kids supposed to take asprin?
NO!
can cause Reye Syndrome
Reye syndrome:
swelling of the brain and hepatitis in liver
T/F: All spinal nerves receive from dermatome.
false
the C1 is the only exception
Dermatone:
specific area of skin that sends a signal to spinal nerves
List of signal transmission:
nerve plexus –> trunks –> anterior and posterior divisions –> cords
List of plexuses:
- cervical from neck
- brachial near shoulder
- lumbar plexus of the lower back
- sacral plexus
- coccygeal plexus
Somatosensory signals are for …
- touch
- heat
- cold
- stretch
- pressure
- pain
and others
Proprioception:
body position and movements to maintain equilibrium
The motor function of these nerve plexuses is…
to stimulate the contraction of skeletal muscles
Cervical plexus receive fibers from the […].
anterior rami of nerves of nerves C1-C5
Cervical plexus gives rise to:
- lesser occipital
- greater auricular
- transverse cervical
- ansa cervicalis
- supraclavicular
- phrenic
Phrenic nerve:
cervical plexus that innervates the diaphragm (essential role in breathin)
Brachial plexus is formed predominantly by the […].
anterior rami of nerves C5 to T1
Brachial plexus passes over the first rib into the [..] and innervates the […] and some […] of the […] and […].
axilla; upper limb; muscles; neck; shoulder
The subdivisions of the brachial plexus are called…
- roots
- trunks
- divisions
- cords
Name the brachial plexus nerves.
- musculocutaneous nerve
- axillary nerve
- radial nerve
- median nerve
- ulnar nerve
Lumbar plexus is formed from the […].
anterior rami of nerves L1 to L4 and some fibers from T12
Lumbar plexus gives rise to the following nerves:
- iliohypogastric nerve
- ilioinguinal nerve
- genitofemoral nerve
- lateral femoral cutaneous nerve
- femoral nerve
- obturator nerve
The sacral plexus is formed from the […}.
anterior rami of nerves L4, L5, and S1-S4
How is the sacral plexus connected to the lumbar plexus?
lumbosacral plexus: fibers that run through the lumbosacral trunk
Sciatic nerve:
tibial and common fibular nerves travel together through a connective tissue sheath
At the […], the tibial and common fibular nerves diverge.
popliteal fossa`
Tibial nerve […] through the leg to the medial and […] nerves in the […].
descends; plantar; foot
Common fibular nerve […] into […] and […] fibular nerves.
divides; deep; superficial
Coccygeal plexus is formed from the […].
anterior rami of S4 and S5