Quiz 8 - Spine & Nerves Flashcards
spinal cord
- spinal cord is enclosed within the vertebral column
- provides two-way communication to and from the brain
- can function with the brain or independently of it
anatomy of spinal cord
protection and coverings - epidural fat (between vertebrae and meninges)
fluid - CSF and interstitial fluid
bone - vertebral column
cross-sectional anatomy of spinal cord
gray matter
white matter
spinal roots
gray matter
consists of cell bodies, unmyelinated nerves and neuroglia
- dorsal horn
- ventral horn
- lateral horn
dorsal horn
somatic and visceral sensory nuclei
ventral horn
somatic motor neurons
lateral horn
somatic motor nuclei
white matter
consists of columns of nerves (funiculi) conveying either sensory tract (ascending tracts) or motor tracts (descending tracts)
spinal roots
dorsal root
dorsal root ganglion
ventral root
spinal nerve
dorsal root
sensory, afferent fibers
dorsal root ganglion
cell bodies of sensory fibers
ventral root
motor, efferent fibers
spinal nerve
formed by dorsal and ventral roots
peripheral nervous system (PNS)
all neural structures outside the brain and spinal cord (ex: sensory receptors, peripheral nerves and ganglia), provides links to and from external environemnts)
spinal nerves
bundles of axons enclosed by connective tissue
- sensory, motor or mixed
structure of PNS
endoneurium
fascicles
perineurium
epineurium
endoneurium
delicate layer surrounding individual axons
fascicles
a bundle of axon
perineurium
wraps fibers into bundles called fascicles
epineurium
tough fibrous layer surrounding several fascicles forming the nerve
31 pairs of spinal nerves
mixed nerves arise from spinal cord and supply all parts of the body (except head) - named according to their point of tissue cervical nerves (C1-C8) thoracic nerves (T1-T12) lumber nerves (L1-L5) sacral nerves (S1-S5) coccygeal nerves (C0)
spinal reflexes
- rapid, involuntary motor response to a stimulus
- usually does not require input from the brain
types of reflexes
autonomic reflexes
somatic reflexes
reflex arc
autonomic reflexes
visceral effectors: smooth and cardiac muscles or glands
somatic reflexes
skeletal muscle effectors
reflex arc
receptor sensory neuron integration center motor neuron effector
receptor
detects physical or chemical changes (stimuli)
sensory neuron
sends information from receptor to integration center
integration center
information processed in central nervous system
motor neuron
sends information from integration center to effector
effector
activated/inhibited by motor neuron
