BB week 4 Flashcards
level at which the spinal cord ends
L2 w/ conus medullaris
cauda equina
spinal nerves L2-L5
white matter of spinal cord
peripheral, ascending and descending fiber pathways
central canal of the spinal cord
continues up into medulla, expands into the cavity of the 4th ventricle, closed on its caudal end, filled w/ CSF
filum terminale
prolongation of pia mater, attaches to back of coccyx
lateral corticospinal tract function
voluntary movement
anterior (ventral) corticospinal tract function
voluntary movement, confined to cervical and upper thoracic spine
lateral spinothalamic tract function
pain/temperature
posterior (dorsal) columns function
proprioception, tactile discrimination, vibratory sense
anterior (ventral) spinothalamic tract function
light touch
posteror (dorsal) spinocerebellar tract function
unconscious proprioception
path and decussation of somatic efferents
originate in motor cortex, travel down through brainstem, decussate in medulla, descend as corticospinal tracts terminate in anterior horn
clinical symptoms that are caused by BOTH UMN and LMN lesions
weakness or paralysis
clinical symptoms distinct to UMN lesions
spasticity, no atrophy, no fasiculations or fibrillations, HYPERtonic reflexes, Babinski may be present
clinical symptoms distinct to LMN lesions
flaccid, atrophy, fibrillation and fasiculations may be present, HYPOtonic reflexes, Babinski absent
examples of UMN diseases
tumors of brain and spinal cord, stroke, MS, meningitis, cerebral palsy, ALS (both UMN and LMN)
examples of LMN diseases
trauma, polio (1% progress to UMN), birth injuries, muscular dystrophies, Guillain-Barre syndrome, carpal tunnel syndrome, mysthenia gravis, ALS (both UMN and LMN)
paresis
weakness (partial paralysis)
-plegia
no movement
paralysis
no movement
palsy
imprecise term for weakness or no movement
hemi-
one side of the body
para-
both legs
mono-
one limb
di-
both sides of body
quadri- or tetra-
all four limbs
axillary nerve innervation
deltoid
musculocutaneous nerve innervation
biceps
radial nerve innervation
triceps, wrist and hand extensors
median nerve innervation
most forearm flexors/pronators
ulnar nerve innervation
intrinsic hand flexors and extensors
obturator nerve innervation
adductor muscles of thigh
femoral nerve innervation
iliopsoas, quadriceps
peroneal nerve innervation
tibialis anterior, peroneal
tibial nerve innervation
gastrocnemius, posterior tibialis
describe the reflex arc
sensory receptor organs exited, impulse travels along a sensory neuron to the posterior root ganglion, first order neuron terminates by synapsing on ventral root ganglion, motor neuron then stimulates a muscle or gland
types of autonomic reflexes
digestion, blood pressure, posture (often go unnoticed because there is no visible or sudden movement)
biceps reflex spinal nerve root
C5, C6
brachioradialis reflex spinal nerve root
C5, C6
triceps reflex spinal nerve root
C7, C8
knee/ patella reflex spinal nerve root
L2-L4
ankle reflex spinal nerve root
L5, S1, S2
plantar reflex (Babinski sign) reflex spinal nerve root
L5, S1, S2
normal Babinski reflex vs. abnormal Babinski reflex
normal: plantar flexion (toe down)
abnormal: plantar extension (toe up)
when to expect an up-going toe w/ Babinski test
infants/children
root reflex
baby turns head in direction of stroking at corner of mouth
suck reflex
suckling in response to touching of roof of mouth
grasp reflex
baby closes hand if stroke palm
tonic neck reflex
fencing posture when head is turned to the side, arm on that side will straighten, opposite arm will bend
moro reflex
startle or loud sound, baby throws head back, extends arms and legs, cries, pulls arms and legs back in
step reflex
baby takes “steps” or dances when held upright and feet ar placed on firm surface
crawl/swim reflex
legs flex/starts to crawl when placed on abdomen
path and decussation of anterior (ventral) spinothalamic tract
sense light touch and pressure, nerves enter spinal cord and decussate almost immediately, travel up opposite side of cord to thalamus, synapse w/ third order neuron
path and decussation of lateral spinothalamic tract
sense pain/temp, nerves enter spinal cord and decussate almost immediately, travel up opposite side of cord to thalamus, synapse w/ third order neuron
path and decussation of posterior (dorsal) columns
nerves enter spinal cord and initially travel up same side, cross over at junction of spinal cord and brainstem, travel to thalamus and synapse w/ third order neuron
posterior (dorsal) column AKA
fasciculus gracilis and fasciculus cuneatus
path and decussation of anterior/posterior spinocerebellar tract
2 neuron pathway!
senses unconscious proprioception, connects cerebellum w/ same side of brain. synapse w/ second neuron occurs in spinal cord.
anterior/ventral root
nerve cell bodies in anterior horn of spinal cord gray matter, conveys signals to motor organs
posterior/dorsal root
nerve cell bodies in posterior horn of spinal cord gray matter, conveys signal from motor organs
PNS nerve cell regeneration
some regeneration possible as long as cell body remains viable, crush injuries may heal with time, cut injuries require surgery and are less easily reversible
cervical nerves
C1-C8
thoracic nerves
T1-T12
lumbar nerves
L1-L5
sacral/coccygeal nerves
S1-S5 and coccygeal nerve
are spinal nerves afferent or efferent?
ALL are MIXED
shoulder dermatome
C5
nipple deramtome
t4
umbilicus dermatome
T10
groin dermatome
L1
how many dermatomes must be damaged to completely lose sensation in an area?
3
which is greater, areas of tactile loss or areas of pain/temperature loss?
tactile loss, because pain/temperature has more extensive overlap
primary function of the autonomic nervous system
regulate blood flow
autonomic nervous system function according to Antoinette
ENTIRELY motor
divisions of the autonomic nervous system
sympathetic and parasympathetic
spinal cord levels of sympathetic nervous system
T1-L2, via cervical, thoracic, lumbar ganglia (ganglia is far from the organ it innervates)
spinal cord levels and cranial nerves of parasympathetic nervous system
S2-S4 (ganglia is close to the organ it innervates), CN III, VII, IX, primarily X
common causes of peripheral neuropathy
DM!!! trauma, infections, metabolic problems, exposure to toxins (chemo)
common descriptives terms for symptoms of peripheral neuropathy
tingling, burning
pattern of sensory loss in peripheral neuropathy
usually both feet, ascending, then fingers, hands, arms (usually bilateral)
tic douloureux
trigeminal neuralgia
sudden “lightening-bolt-like” jab of pain, may be triggered by cold, brushing teeth, drinking, chewing, shaving, may last 15 min or more, often affects middle-aged and elderly, etiology unknown
nerve affected in carpal tunnel
median
pattern of sensory loss in carpal tunnel
thumb, index, middle finger
central pain syndrome
AKA thalamic pain syndrome, neurological condition, affects people differently, caused by damage to CNS (stroke, thalamus or brainstem damage, MS, spinal cord injury, reaction to meds, TBI), deep burning, aching, cutting, tearing sensation, sometimes sudden shots of pain.
complex regional pain syndrome
AKA reflex sympathetic dystrophy, chronic pain condition, intense pain out of proportion to the severity of injury, gets worse rather than better over time, most often affects one of arms, legs, hands or feed, often pain spreads, dramatic changes in color and temp of skin over affected area, cause unknown, sympathetic nervous system likely plays a role
tertiary syphillis
AKA neurosyphillis, can follow initial infection by 3-15 years, spirochetes continued to reproduce for years, damage accumulates in bones, skin, nerves, heart, arteries, lesions are called gummas and are very destructive
gummas
lesions from tertiary syphillis
3 factors that determine the severity of seizure
location, extent of reach into tissues, duration
