nervous system Flashcards
functional unit, specialized cells that transmit impulses
neurons
non conducting cells, provide nutritional and structural support
glial cells
afferent neurons, sense and relay stimuli to CNS, unipolar, sometimes bipolar
sensory neurons
clusters of sensory neurons in PNS
ganglia
integrate and interpret sensory info, in brain and spinal cord, multipolar
interneurons
relay info to effectors which produce a response, multipolar
motor neurons
contain a single process connected to soma
unipolar
contain 2 processes connected to soma
bipolar
contain multiple processes connected to soma
multipolar
dendrites, soma, axon, end brush
4 main parts of neuron
cytoplasm extensions, branched, receive and transmit signals
dendrites
contains large nucleus, contains organelles, receives and integrates impulses from dendrites, if large enough excitation, then impulse moves to axon hillock to axon
soma
long extension of cytoplasm, carries nerve impulses to effectors or other neurons
axon
slower, has to travel from each separate section
unmyelinated axon
covered in myelin sheath made of schwann cells, which insulate neuron and prevent ion loss, nodes of ranvier which impulses jump to and from
myelinated axon
contains axon terminal and axon terminal button which connects neurons through synapses
end brush
sensory receptor, sensory neuron, interneuron, motor neuron, effector
reflex arc components
doesnt have interneuron e.g. knee jerk reflex
monosynaptic reflex arc
numerous neurons held together by connective tissue, located in PNS
nerves
specialized cells that wrap around axons, forming myelin sheath in CNS
oligodendrocytes
specialized cells that wrap around axons, forming myelin sheath in PNS
schwann cells
star shaped glial cells that hold neurons in place in CNS, release gliotransmitters, regulate blood flow, oxygen and nutrients
astrocyte
glial cells that provide physical support to neurons in PNS
satellite cells
line cavities of CNS, make up walls of ventricles in brain, create & secrete cerebrospinal fluid
ependymal cells
special immune cells only found in brain CNS, detect abnormalities and engulf bacteria and viruses using phagocytes
microglia
where spinal cord exits
foramen magnum
3 layers of connective tissue around spinal cord
meninges
clustered spinal nerves
plexus
