Organization of NS/Spinal Reflex Connections Flashcards
what does extrinsic control maintain and do?
homeostasis
glandular activity
control of movements
perception of environments
transfer of information
storage information
what do neurological exams evaluate?
mental status and behavior
cranial nerves
spinal reflex
proprioception
muscle strength and tone
coordination
gait
what are the anatomical components of a neural circuit?
inputs (afferents)
integrators
outputs (efferents)
what is the functional components of sensory inputs, computational units, and output nerves?
sensory inputs - sensory neuron/receptor
computational units - brains and ganglia
output nerves - output to skeletal muscle, SM or glands
what are the two divisions of the peripheral NS?
afferent
efferent
what are the divisions of efferent?
somatic NS - voluntary
autonomic NS - involuntary
what does the afferent division of the PNS break down into?
sensory and visceral stimuli
what are the divisions of the somatic, and autonomic NS?
somatic - motor
autonomic - sympathetic, parasympathetic, enteric NS
what does the cotton ball test test?
sensory - visual
motor - eye movement
what are the 4 types of movement?
- voluntary movement
- postural movement
- rhythmic movement
- reflex movement
what type of movement is the cotton bell test?
voluntary
what type of movement is skeletal muscle holding up posture?
postural
what type of movement walking, chewing, breathing?
rhythmic
what type of movement in response to a stimulus?
reflex
what are the two major cell types of the nervous system?
neurons
neuroglia
what part of the nerve produces neuropeptides?
Soma - body
golgi apparatus & rER
what part of the neuron is the site of synapse?
dendrites/dendritic spines
what is the primary neuronal output?
axon
what part of the neuron releases neurotransmitters?
synaptic terminal of the axon
what are the CNS neuroglia?
astrocytes
microglia
ependymal cells
oligodendrocytes
what are the PNS neuroglia?
schwann cells
what are the 3 types of nerve fibers that occur in the PNS?
A,B,C
Order A nerve fibers from largest to smallest
Aa, AB, Ad
Order A nerve fibers from fastest to slowest
Aa, AB, Ad
which nerve fiber has the muscle spindle and golgi tendon information?
Aa
which nerve fiber is proprioceptors of skeletal muscle?
Aa
which nerve fiber has the muscle spindle, touch, and proprioception?
AB
which nerve fiber carries pain and temperature?
Ad
which nerve fiber is a mechanoreceptor of the skin?
AB
which nerve fiber is a mechanical nociceptor?
Ad
which nerve fiber are preganglionic efferent ANS fibers?
B
what nerve fiber carries information of temperature, dull pain, and itch?
C fibers
Is the dorsal root/dorsal horn afferent or efferent?
afferent
Is the ventral root/ventral horn afferent or efferent?
efferent
what are the two neuron chains?
upper motor neurons
lower motor neurons
Is the lateral corticopsinal and ventral corticospinal part of UMN or LMN?
UMN
where does the lateral and ventral corticospinal cross?
lateral - medulla
ventral - cross at termination of spinal cord/ uncrossed
where are UMN and LMNs?
UMN - primary motor cortex
LMN - spinal cord
what are the pathways that control movement? (UMN)
-lateral corticospinal
-rubrospinal
-ventral corticospinal
-vestinbulospinal, reticulospinal, tectospinal tract
what two descending efferent pathways are crossed?
lateral corticospinal
rubrospinal
what are the two descending efferent pathways that are uncrossed?
ventral corticospinal
vestibulospinal;reticulospial;tectospinal
which two descending efferent pathways involve voluntary skeletal muscle control?
lateral corticospinal
ventral corticopspinal
what two descending efferent pathways involve involuntary skeletal muscle control?
rubrospinal
vestibulospinal; reticulospinal; tectospinal
Is CDM a UMN or LMN disease?
starts UMN and progresses to LMN
primarily UMN
what is the initial presentation of canine DM?
UMN paresis localized to T3-L3 spinal segments, spastic paresis, exaggerated reflexes
what is it important to rule out when diagnosing DM?
spinal compression
which diameter of fibers lose function first - large or small?
large first then small
which is a better prognosis - tactile function lost or deep pain lost?
tactile function lost
what is feline diabetic neuropathy associated with?
diabetes mellitus
Is feline diabetic neuropathy a UMN or LMN disease?
LMN
what is the presentation of cats with feline diabetic neuropathy?
plantigrade stance
sensory nerve dysfunction
what are the two types of reflexes?
simple or basic
acquired or conditioned
what are the 5 basic component of a reflex circuit
receptor
afferent pathway
integrating center
efferent pathway
effector
List proprioceptors involved in reflexes
golgi tendon organ
muscle spindles
List nociceptor involved in reflexes
free nerve endings in joint capsules and skin
what does golgi tendon organs measure?
tension
what does muscle spindles measure?
velocity of length change
length of muscle fiber
what afferents innervate muscle spindles? what does each detect?
group 1A afferents - detect velocity of length change
group 2 - detect length of muscle fiber
what motorneurons innervate muscle spindles?
static Y
dynamic Y
which motor neurons and afferents innervate nuclear-bag fibers?
group 1A
dynamic y
which motor neurons and afferents innervate nuclear chain fibers?
Group 1A
group 2
static y
when a muscle is stretch which afferents are activated?
group 1A and group 2
what is the role of a fibers and y fibers in a-y coactivation?
A-motor neurons activate extrafusal fibers -> shortening of muscle
y-motor neurons activate intrafusal fibers -> shortening of muscle spindle
what dose the monosynaptic stretch reflex maintain?
posture and muscle tone
Map out the flow of a monosynaptic stretch reflex (measured by -> activate -> excite)
stretch measures by muscle spindle -> activates sensory neuron -> a motor neuron excitation
what does the 2 or more synpases in a polysnaptic stretch reflex allow for?
reciprocal innervation
which is faster monosynaptic or polysynaptic stretch reflex?
monosynaptic
Map out the flow of a polysnaptic stretch reflex
sensory neuron -> interneuron -> motor neuron
which polysynaptic reflex activates extensors and inhibits opposing flexor?
stretch
which polysynaptic reflex activates flexors and inhibits opposing extensors?
pain
Map out the flow of a flexor withdrawl reflex
noxious stimulus activates nociceptor -> afferent pathway -> integrating center (spinal cord) -> efferent pathway -> flexor contract, extensor relax
what allows for weight to be shifted to uninjured leg so we dont fall in the event of noxious stimulus to a root?
crossed extensor reflex
what does the crossed extensor do?
contracts extensor muscle of opposite limb
flexes muscle of opposite limb
what are the ascending afferent pathways?
dorsal lemniscus columns
ventral spinothalamic
lateral spinothalamic
what does the dorsal lemniscus columns sense?
conscious muscle sense - awareness of body positions, crossed touch, pressure, vibration
what does the lateral spinothalamic sense?
pain and temperature
what does the ventral spinothalamic sense?
touch
which two ascending afferent pathways cross?
lateral and ventral spinothalamic
what is the cutaneous trunchi (panniculus) reflex?
cutaneous trunchi muscle sensory neurons respond to tactile stimulation -> skin contractions
what happens if there is a lesion to the spinal cord that blocks the conduction of the afferent sensory tracts of the cutaneous trunch muscle?
arefexia - tactile stimulation no longer produces contractions
what proprioception collected through?
golgi, muscle spindles, free nerve endings
what is a segmental reflex?
transverse one or few segments of brain divisions
what is a intersegmental reflex?
transverses several segments of spinal cord or several brain divisions
what is a long-loop intersegmental reflex?
transverses many segments of spinal cord and/or brain divisions, enter and leaves CNS at same location
which is a segmental, intersegmental, and long-loop intersegmental reflex?
A - segmental
B - intersegmental
C - long-loop intersegmental
fill in the chart for the menace test
