Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
102 Cards in this Set
- Front
- Back
number of cervical spinal nerve pairs
|
8
|
|
number of thoracic spinal nerve pairs
|
12
|
|
number of lumbar spinal nerve pairs
|
5
|
|
number of sacral spinal nerve pairs
|
5
|
|
number of coccygeal spinal nerve pairs
|
1
|
|
Why does the spinal cord have a cervical enlargement?
|
It contains the nerves of the upper limbs
|
|
Why does the spinal cord have a lumbar enlargement?
|
It gives rise to nerves of the pelvic region and lower limbs
|
|
Why are there 8 cervical spinal nerves?
|
Because the C1 vertebrae has an extra spinal nerve that is above the C1 vertebrae, when normally they all have spinal nerves below
|
|
medullary cone
|
inferior to the lumbar enlargement the cord tapers to this point
|
|
cauda equina
|
the lumbar enlargement and medullary cone give off a bundle of nerve roots that occupy the vertebral canal from L2-S5. These innervate the pelvic organs and lower limbs
|
|
Gray matter
|
contains nerve cell bodies, dendrites, neuroglia and unmyelinated axons
|
|
White matter
|
Contains myelinated nerve fibers
|
|
Posterior and anterior horns
|
made of gray matter
|
|
What are the posterior and anterior horns connected by?
|
Connected by gray commissure which forms the central canal in the middle and it consists of cerebrospinal fluid
|
|
What type of neurons are located in the anterior horns?
|
motor
|
|
What type of neurons are located in the posterior horns?
|
sensory
|
|
Which horn (anterior or posterior) is the cell body (soma) of the sensory neurons?
|
posterior
|
|
White matter contains?
|
myelinated nerve fibers. it consists of bundles of axons that course up and down the cord and provide avenues of communicated between the different levels of the CNS.
|
|
nerve fiber
|
nerve process (axon or dendrite)
|
|
Nerve
|
bundle of nerve fibers in PNS (mixed-combo of sensory and motor)
|
|
tract
|
bundle of nerve fibers in the CNS (mixed-combo of sensory and motor)
|
|
mixed
|
combo of sensory and motor
|
|
ganglion
|
cluster of neuronal cells bodies in PNS
|
|
nucleus
|
cluster of neuronal cells bodies in CNS
|
|
The brain and spinal cord are enclosed in three connective tissue membranes called
|
meninges
|
|
dura matter
|
most superficial sheath, it is a tough collagenous membrane about as thick as a rubber kitchen glove
|
|
epidural space
|
the space between the sheath and vertebral bone that is occupied by blood vessels, adipose tissue, and loose connective tissue
|
|
arachnoid matter
|
middle sheath that is closest to the dura matter
|
|
subarachnoid space
|
the gap between the arachnoid membrane and the pia matter that is filled with cerebrospinal fluid
|
|
From which space is a spinal tap taken? (vertebral and spinal)
|
Between the spinous process of L3 and L4 and CSF can be ejected from the subarachnoid space
|
|
Which space is an epidural anesthetic injected?
|
Into the epidural space where there is fat and it will hit the spinal nerves around it. Used during labor and delivery and surgery in the pelvis or leg
|
|
Which space is a spinal anesthetic injected?
|
Goes into the spinal cord in the space inferior to L1-L2 (below cord) in the subarachnoid space. Used for genital, urologic, or lower body procedures
|
|
Which vertebral level is safest place to inject anesthetic or take a sample of CSF?
|
Between the spinous processes of L3 and L4 because the spinal cord doesnt extend this far and is not exposed to injury
|
|
decussation
|
when the spinal nerve tracts cross over from the left side of the body to the right side, or vice versa
|
|
contralateral
|
When the origin and destination of the tract are on opposite sides of the body
|
|
ipsilateral
|
When a tract does not decussate, so the origin and destination of its fibers are on the same side of the body
|
|
ascending tracts
|
carry sensory information up the cord
|
|
descending tracts
|
conduct motor impulses down
|
|
1st order neuron
|
detects a stimulus and conducts a signal to the spinal cord or brainstem
|
|
2nd order neuron
|
continues to the thalamus at the upper end of the brainstem
|
|
3rd order
|
carries the signal the rest of the way to the sensory region of the cerebral cortex
|
|
sensory
|
ascending tract
|
|
motor
|
descending tract
|
|
upper motor neurons
|
neurons that bring messages from the brain down to the spinal cord
|
|
lower motor neurons
|
Neurons that branch out from the spinal cord and the muscles and tissues of the body
|
|
nerve fiber
|
Nerve process (axon or dendrite)
|
|
Nerve
|
Bundle of nerve fibers in the PNS (mixed)
|
|
Tract
|
Bundle of nerve fibers in the CNS (mixed)
|
|
Mixed
|
Combination of motor and sensory nerve fibers
|
|
Ganglion
|
cluster of neuronal cell bodies in PNS
|
|
Nucleus
|
Cluster of neuronal cell bodies in the CNS
|
|
Ascending tract sends what type of information?
|
Sensory info to the brain
|
|
Descending tract sends what type of information?
|
Motor info to the spinal cord and limbs
|
|
What is the order of sensory neurons traveling up the general spinal tract?
|
Spinal cord, medulla, midbrain, brain
|
|
What type of signals does the spinothalamic tract send?
|
Carries signals for pain, temperature, pressure, tickle, itch, and light or crude touch.
|
|
Where do 1st order neurons end in the spinothalamic tract?
|
In the dorsal horn of the spinal cord
|
|
What do the second order neurons in the spinothalamic tract do?
|
they decussate to the opposite side and lead all the way to the thalamus
|
|
Where do the 2nd and 3rd order neurons synapse?
|
In the thalamus and continue to the cerebral cortex
|
|
What happens when you damage the spinothalamic tract?
|
you lose the ability to sense all those specific things (touch, tickle, itch, temperature, pain and pressure) in a certain area
|
|
What is the descending tract?
|
carries motor signals down the brainstem and spinal cord and involves two neurons called the upper and lower motor neurons
|
|
upper motor neuron
|
Begins with a soma in the cerebral cortex or brainstem and has an axon that terminates on the lower motor neuron
|
|
lower motor neuron
|
the axon in the brain or spinal cord leads the rest of the way to the muscle or target organ
|
|
Corticospinal tract
|
Carries motor signals from the cerebral cortex for precise, finely coordinated limb movements`
|
|
Where does the UMN decussate in the corticospinal tract?
|
in the lower medulla and form the lateral (ventral) corticospinal tract on the contralateral side of the spinal cord
|
|
Reflex arc pathway
|
From a sensory nerve ending to the spinal cord or brainstem and back to a skeletal muscle
|
|
During a reflex reaction is information sent to the brain?
|
Yes, but it is not involved in the actual reflex motion. This information signals pain and it is relayed slower to the brain
|
|
Somatic reflexes
|
responses of skeletal muscle, such as quick withdrawl of your hand form a stove
|
|
Stretch reflex
|
Increased muscle tension in response to stretch. Serves to maintain equilibrium and posture, stabilize joints, and make joints smoother and better coordinated. It is a monosynaptic spinal reflex so there is no interneuron involved and the afferent neuron synapses directly with an efferent neuron
|
|
Is the spinal cord is severed at a higher area like T1 will the patient still have a stretch reflex?
|
Yes because the signals do not need to go to the brain
|
|
Flaccid paralysis
|
No reflexes occurs at the lower motor neurons
|
|
Spastic paralysis
|
exaggerated reflexes, no inhibitory control from UMN
|
|
What part of the spinal cord is damaged with ALS?
|
Degenerating of the upper and lower motor neurons. It is a paralysis of voluntary muscles. Also known as Lou Gehrig's disease. The person is cognitively intact then slowly start losing motor function, breathing ability and they can have respiratory failure
|
|
What part of the spinal cord is damaged with polio?
|
Degeneration of the lower motor neurons. Occurs in the ventral horn and causes paralysis.
|
|
Sensory nerves are______
|
Posterior or dorsal
|
|
Motor nerves are _____
|
Anterior or ventral
|
|
Dorsal root ganglion
|
the dorsal root expands into this which contains the somas of the sensory neurons carrying signals to the spinal cord
|
|
Immediately after emerging from the intervertebral foramen the nerve divides into what?
|
a dorsal and venral ramus
|
|
What does the dorsal ramus innervate?
|
the muscles and joints in that region of the spine and skin of the back
|
|
What does the ventral ramus innervate?
|
The ventral and lateral skin and muscles of the trunk and gives rise to the nerves of the limbs
|
|
What do the anterior rami of the spinal cord levels T1-T11 form?
|
Intercostal nerves between the ribs which innervate the intercostal muscles for breathing, the abdominal muscles and the skin on the anterior and lateral side of the body
|
|
The book calls the T12 anterior rami an intercostal nerve, why is this incorrect?
|
Its more correct name is subcostal nerve
|
|
Dermatome
|
An area of the skin innervated by a specific spinal nerve
|
|
Where does the shingles virus remain latent?
|
dorsal root ganglia
|
|
When the shingles virus becomes reinactivated what happens?
|
If the immune system is compromised the virus can travel down the sensory nerves by axonal transport and cause shingles.
|
|
What are the signs of shingles?
|
a painful trail of skin discoloration and fluid filled vesicles along the path of the nerve
|
|
Nerve plexus
|
group of anterior rami traveling together
|
|
What are the 4 nerve plexuses?
|
Cervical, brachial, lumbar, and sacral
|
|
Cervical plexus
|
anterior rami of C1-C5, innervates head, neck and upper shoulders and the phrenic nerve for this rami from C3-C5
|
|
Phrenic nerve
|
Roots from C3-C5 brings motor nerves to the diaphragm enabling you to breath
|
|
Brachial plexus
|
Ventral rami of spinal nerves C5-T1 (C4-T2), innervates arms and shoulders. It also has the ulnar nerve which is our funny bone
|
|
The brachial plexus travels deep to which bone?
|
The clavicle
|
|
Damage to the brachial plexus would result in
|
Damage to the lower motor neurons and it would cause flaccid paralysis
|
|
Sacral plexus
|
Ventral rami of spinal nerve L4-S4, innervates the gluteal region, posterior thigh and leg and contains the sciatic nerve
|
|
Sciatica
|
Injury to the sciatic nerve. IVD herniation, osteoarthritis, damage along pathways. Feel numbness and pain down the back of their leg caused by pressure on that area for a prolonged time.
|
|
Complete severance of the spinal cord
|
Causes immediate loss of motor control at and below the level of injury. Victims lose all sensation from the level of injury and below
|
|
Spinal shock
|
The early symptoms of spinal injury where the muscles below the level of injury exhibit flaccid paralysis (inability to contract) and an absence of reflexes because of the lack of stimulation at the higher level of the CNS.
|
|
Flaccid paralysis is due to damage in the
|
LMN
|
|
Spastic paralysis is due to damage in the
|
UMN
|
|
Spastic paralysis
|
Starts with chronic flexion of the hips and knees and progresses to a state in which the limbs become straight and rigid
|
|
Paraplegia
|
paralysis of both of the lower limbs resulting in spinal cord lesion at levels T1 to L1
|
|
quadriplegia
|
the paralysis of all four limbs resulting from lesions above level C5
|
|
hemiplegia
|
paralysis of one side of the body, usually resulting in spinal cord injuries but not a stroke from C5 to C7
|