Flashcards in Chapter 13: Spinal Cord, Nerves, & Somatic Reflexes Deck (68)
nerve fibers that conduct info up and down the spinal cord (CNS)
input from multiple sources, integrated & executed output
repetitive, coordinated contractions of several muscle groups
STAY AT THE SPINAL CORD LEVEL
involuntary stereotyped responses
cylinder of nervous tissue that arises from the brainstem at the foramen magnum of the skull
spinal cord passes through_____ and gives rise to ___ pairs of spinal nerves.
vertebral canal; 31
Where do the 31 spinal nerves pass?
1st pair: between the skull & C1
rest through intervertebral foramina
What 2 parts of the spinal cord are thicker than elsewhere?
-cervical enlargement (upper limbs)
-lumber enlargement (lower limbs)
cord tapers to a point inferior to lumbar enlargement
bundle of nerve roots that occupy the vertebral canal from L2 to S5
three fibrous connective tissue membranes that enclose the brain & spinal cord
What are the 3 meninges (superficial to deep)?
-dura mater, arachnoid mater, & pia mater
What is special about the pia mater?
it is continuous with the brain & spinal cord
What space surrounds the meninges?
spina bifida? How is it prevented?
-congenital defect in which one or more vertebrae fail to form a complete vertebral arch for enclosure of the spinal cord
-prevented via folic acid(B vitamin)
The ____ is shaped like a butterfly and is surround by the ___ in 3 columns.
gray matter; white matter
gray matter (2)
-site of info processing, synaptic integration
white matter (2)
-carry signals from one part of the CNS to another
columns of funiculi
3 pairs of these white matter bundles (posterior, later, ventral columns)
carry sensory info up the spinal cord (afferent)
carry motor info down the spinal cord (efferent)
the fibers pass up or down the brainstem & spinal cord they CROSS OVER from left to right (CROSS OVER EVENT)
when the origin & destination of a tract are on opposite sides of the body
when the origin & destination of a tract are on the same side of the body
What are the 3 sensory neurons of the ascending tract?
first order, second order, third order neurons
first order neuron (ASCENDING)
detect the stimulus & transmit signal to spinal cord/brain
second order neuron (ASCENDING)
continues to the thalamus at the upper end of brainstem
third order neuron (ASCENDING)
carries the signal the rest of the way to the cerebral cortex
ascending tracts (5)