Chapter 13: The Spinal, Spinal Nerves, and Somatic Reflexes Flashcards
nerve fibers conduct sensory and motor information up and down the spinal cord
conduction
spinal neurons receive input from multiple sources integrate and execute appropriate output
neural integration
spinal cord contains central pattern generators group of neurons that coordinate repetitive sequences of contractions for walking
locomotion
involuntary responses to stimuli that are vital to posture coordination and protection
reflexes
cylinder of nervous tissue that arises from the brainstem at the foramen magnum of the skull
spinal
where does the spinal cord’s inferior margin end?
L1
what segments is the spinal cord divided into?
cervical, thoracic, lumbar, and sacral
nerves to upper thigh
cervical enlargement
nerves to pelvic region and lower limbs
lumbar enlargement
cord tapers to a point inferior to lumbar enlargement
conus medullaris
bundle of nerve roots that occupy the vertebral canal from L2 to S5
cauda equina
three fibrous membranes that enclose the brain and spinal cord
meninges
what are the meninges from superficial to deep?
dura mater, arachnoid mater, and pia mater
what separates the vertebrae from dura mater?
epidural space
delicate membrane that follows contours of spinal cord?
pia mater
pia mater continues inferiorly as the
filum terminale
what is the subarachnoid space filled with?
cerebrospinal fluid (CSF)
congenital defect in which one of more vertebrae fail to form a complete vertebral arch for enclosure of the spinal cord
spina bifida
what is the most serious form of spina bifida?
spina bifida cystica
what reduces the risk of spina bifida
folic acid
when does spina bifida occur?
defect occurs within the first 4 weeks of development
contains neuron cell bodies with little myelin; site of information processing, synaptic integration
gray matter
contains myelinated axons; carries signals from one part of the CNS to another
white matter
contains interneuron cell bodies
dorsal (posterior) horns
made up of only sensory fibers
dorsal (posterior) root
contains motor neuron cell bodies
ventral (anterior) horns
made up only of motor fibers
ventral anterior root
connects right and left sides; central canal lined with ependymal cells filled with CSF
gray commissure
T2 through L1; contains neurons of sympathetic nervous system
lateral horn
columns of funiculi
posterior (dorsal), lateral, and anterior (ventral) columns
subdivisions of columns or funiculi
tracts or fasciculi
spinal tract; carry sensory information up
ascending tracts
spinal tracts; carry motor information down
descending tracts
crossing of the midline that occurs so that the brain senses and controls the contralateral side of body
decussation
spinal tracts; origin and destination on opposite sides of the body
contralateral tracts
spinal tract; have an origin and destination on the same side of the body
ipsilateral tract
detect stimulus and transmit signal to spinal cord or brainstem
first order neurons
continue to the thalamus at the upper end of the brainstem
second order neurons
carry the signal the rest of the way to the sensory region of the cerebral cortex
third order neurons
ascending tracts: carries signals from midthoracic and lower parts of body
gracile fasciculus
nonvisual sense of the position and movements of the body
proprioception