Chapter 11: The Nervous System Flashcards
(35 cards)
nerve
bundle of axons and their sheaths that connects CNS to sensory receptors, muscles, and glands
sensory receptors
ends of neurons or separate specialized cells that detect sensations
ganglion
collection of neuron cell bodies outside CNS
plexus
extensive network of axons and sometimes neuron cell bodies, located outside CNS
somatic nervous system
CNS to skeletal muscles
voluntary
single neuron system
synapse
junctions of a nerve cell with another cell
autonomic nervous system
from CNS to smooth muscle, cardiac muscle, and certain glands
involuntary
two neuron system
sympathetic, parasympathetic, enteric
sympathetic
prepares body for physical activity
parasympathetic
regulates resting or vegetative functions, such as digesting food or emptying bladdar
sensory division of the PNS
afferent: transmits action potentials from receptors to CNS
Motor Division of the PNS
efferent: transmits action potentials from CNS to effectors
organization of neurons
- cell body: soma
- dendrites: input
- axons: output
sensory or afferent neuron
action potential toward CNS
motor or efferent neuron
action potential away from CNS
interneurons or association neuron
within CNS from one neuron to another
Multipolar
motor neurons
bipolar
sensory in retina of the eye and nose
astrocytes
nourish neurons
blood brain barrier
protects neurons from toxic substances, allows exchange of nutrients and wastes products between neurons and blood
ependymal cells
form choroid plexuses which secrete cerebrospinal fluid
microglia
specialized macrophages that respond to inflammation, phagocytize invaders
oligodendrocytes
sheet that forms and protects myelin sheaths that surround axon
Schwann cells
neuroglia in the PNS that wrap around axons, form myelin sheath around portion of one axon
satellite cells
surround neuron cell bodies in sensory ganglia, provide support and nutrients