week 7 - cns Flashcards
CNS
brain and spinal cord
PNS
all neurons or parts of neurons outside the CNS
what PNS comprise of ?
somatic nervous system and autonomic nervous system
somatic nervous system
controlling voluntary action via skeletal muscle
autonomic nervous system
visceral functions such as heart rate and breathing
part of autonomic nervous system
enteric nervous system
enteric nervous sytem
digestion and movement of the gut. it gets input from spinal cord but it can also work independently
glia
cells in cns and pns, which support and protect neurons
white matter
myelinated axons running in bundles called tracts
ventricles
in cns, filled with cerebrospinal fluid; lateral ventricles, third ventricle, fourth ventricle
gray matter
nerve cell bodies, unmyelinated axons, denreites
tracts
myelinated axons running in bundles (CNS)
ganglia
PNS – clusters of neurons
nerves
PNS — bundles of axons
how much blood and glucose does the brain use
gets 15% of blood pumped by heart, consumes half of body’s glcose
how do neurons communicate with each other
sending action potential down their axons, it requires a lot of firing
what type of firing can energy supply to CNS support
low rate of firing; any at moment only 4% of all neurons are firing
segments in spinal cord
31 seegments, each with a pair of spinal nerves
roots in spinal nerve
dorsal and ventral
dorsal root
carries afferent (incoming, sensory signals)