Nervous system Flashcards
Functions of NS
enables continuous adaptation to internal/external environment,
controls and integrates activities of the body,
effector component of human movement system that governs movement
Composed of:
neurons and neuroglia
Neurons
base structure and functional units of NS,
allows for rapid communication,
communication through neurotransmiters
Neuroglia
5x more adundant than neurons,
nonexcitable,
serve to support, insulate and nourish neurons
types of neurons
multipolar motor neuron & pseudounipolar sensory neuron
types of neurolgia in CNS
astrocytes, microglia, oligodendrocyte & ependymal cells
astrocyte cells
form matrix and deliver nutrients
microglia cells
clean up
oligodendrocytes cells
produce myelin, provide support, wrap multiple cells
ependymal cells
produce CSF
types of neuroglia in PNS
satelite cells & schwann cells
Central NS
brain & spinal cord, integrates and coordinates afferent and efferent signals, structured with nuclei and tracts
Gray Matter location of
neuron cell bodies of sensory motor and presynaptic visceral motor neurons
White matter location of
interconnecting fiber tracts
Meninges
Dura mater, Pia mater, arachnoid mater
Dura mater
thick tough outermost layer
pia mater
delicate and transparent innermost layer
arachnoid mater
delicate avascular intermediate layer
Peripheral NS
NS outside of CNS, anatomically and operationally continuous with CNS
cell bodies collected in ganglion (sensory and motor)
Afferent Neuron
sensory of PNS
Efferent Neuron
motor of CNS, sends communication to organs
Cranial Nerves has ____ pairs
12, 11 arise from brain, 1 from superior spinal cord
Spinal Nerves have ____ pairs
31, 8 central, 12 thoracic, 5 lumbar, 5 sacral, 1 coccyx
Anterior ramus
motor, supply to anterior trunk, lateral trunk, upper/lower limbs
Posterior ramus
sensory, supply nerves to synovial joint of vertebra, back and skin in area
rami that doesn’t form plexus
posterior
rami that contains fibers from spinal nerves
anterior rami
multiple rami -> ____ -> musculocutaneous nerve
plexus
heel innervation level
S1-2, tibial
lateral heel innervation level
S1-2, sural
lateral plantar innervation level
S1-2
Medial plantar innervation level
L4-5
saphenous innervation level
L3-4
Lateral femoral cutaneous innervation level
L2-3
Lumboinguinal of genitalfemoral innervation level
L1-2
ilioinguinal innervation level
L1
Lateral femoral cutaneous innervation level
L2-3
Common peroneal innervation level
L2-3
Superficial peroneal innervation level
L4-5
Deep peroneal innervation level
L4-5
Anterior femoral cutaneous innervation level
L2-3
Iliohypogastric innervation level
L1
superior cluneal innervation level
Post division of S1-3
Middle cluneal innervation level
post division of S1-3
Post femoral cutaneous innervation level
S1-3
Lateral femoral cutaneous innervation level
L2-3
Superior peroneal innervation level
L4-S1
Dermatome C5
mid-deltoid
dermatome C6
dorsal aspect of thumb webspace
dermatome of C7
dorsal aspect of middle finger
dermatome of C8
medial border of fifth metacarpal
dermatome of T1
medial forarm
dermatome of L1
inguinal area
dermatome of l2
ant mid thigh
dermatome of L3
medial knee
dermatome of l4
medial malleolus
dermatome of l5
distal medial dorsum of foot
dermatome of S1
lateral boder of foot
Dermatome of S2
medial/post calcaneus
myotome
unilateral mass of muscle inervated by motor fibers of single spinal nerve
Myotome of C1-2
cervical flex
myotome of C3
cerivcal side bending
myotome of C4
scap elevation
myotome of C5
shoulder abd
Myotome of C6
elbow flex
myotome of C7
elbow ext
Myotome of C8
thumb abd
Myotome of T1
finger abd
Myotome of hip flexion
L2-3
Myotome of knee ext
L3-4
Myotome of ankle dorsiflex
L4-5
Myotome of great toe ext
L5
Myotome of knee flex & ankle eversion
L5-S1
Myotome of ankle plantar flex
S1-2
radiculopathy may present
muscle weakness, broad less profound effects
musculocutaneous nerve injury may present
muscle weakness, isolated and profound effects
injury with hyperreflexia is
CNS
injury with hyporeflexia is
PNS
muscle stretch reflex of L2-4
quadriceps
muscle stretch reflex of L5
medial hamstrings
muscle stretch reflex of S1-2
gastroc-soleus
Nerve fiber types
somatic & visceral sensory and motor fibers
cell bodies of sensory fibers location
spinal or cranial ganglion
cell bodies of post synaptic motor neurons (outside CNS) located
automatic ganglion
somatic sensory nerve fibers
afferent from skin, muscles, tendons and joints
enters spinal ganglion of post nerve root
somatic motor nerve fibers
efferent to skeletal muscles
leaves through ant nerve root
visceral sensory nerve fibers
afferent from organs
enters spinal ganglion of post nerve root
visceral motor nerve fibers
efferent to smooth muscle and tissues
leaves through ant nerve root
Somatic NS
Voluntary, CNS and PNS providing general sensory motor innervation to the body
Automatic NS
Involuntary, afferent and efferent signals sent to/from viscera to smooth muscle, cardiac muscle and glands
Sympathetic & Parasympathetic are divisions of
ANS, typically contrast in coordinated effects
Sympathetic effects of SNS
prepare body for fight or flight (catabolic)
SNS extends between
1st thoracic and 2nd/3rd lumbar segments, “thoracolumbar”
SNS Presynaptic cell bodies are short/long?
short
Postsynaptic cell bodies are found in ___
paravertebral and prevertebral ganglion
Parasympathetic NS effects
promote normal functioning and conserve energy
Parasympathetic presynaptic cell bodies are found in
brainstem (exit through cranial n), sacral segments of spinal cord (exit through spinal n)
Parasympathetic NS presynaptic cell bodies are short/long?
long
Parasympathetic NS postsynaptic cell bodies are short/long?
short
SNS Postsynaptic cell bodies are short/long?
long
Enteric Nervous System
3rd component fo visceral motor system, “2nd brain”
Functions w/o CNS or Autonomic NS
Enteric NS includes:
postsynaptic parasympathetic neurons of gastrointestinal tract
ENS function
integrates with exocrine and endocrine secretion, vasomotion, micromotility and immune activity of the gut
ENS visceral afferent fibers provide
info about condition of body’s internal environment, can trigger visceral/somatic reflexes
can produce conscious perceptions of pain, cramps, hunger, fullness, nausea