NERVOUS SYSTEM Flashcards
anything that can cause excitation or activation
stimulus
a wave of excitation transmitted through nervous
tissues (along neuron connections)
impulse
an automatic and involuntary response to change
reflex
is the primary functional cell of the nervous system. This
cell is highly excitable, which results in the rapid transmission of information
neuron
cell body
soma
are neuronal
processes that transmit electrical signals toward the cell body
dendrites
a neuronal process responsible in conducting electrical signals away from the
cell body
axon
conduct signals from receptors to the central nervous
system (CNS)
sensory
or afferent neurons
conduct signals from the CNS to effector organs such as muscles and glands
motor or efferent neurons
conduct signals from one neuron to another, and are
mainly confined to the CNS
interneurons or
association neurons
having only one process
unipolar neurons
having
one dendrite and one axon, and these are common in sensory system
bipolar neurons
are sensory neurons having their single dendrite and
axon fused resulting to a single process appearance
pseudounipolar neurons
having a number of dendrites and a single axon
multipolar
neurons
Supporting cells of the nervous system
neuroglia
are cells of the CNS that form the myelin
sheaths that surround axon of neurons
Oligodendrocytes
are cells of the CNS that regulate extracellular brain
fluid composition and promote tight junctions to form the bloodbrain barrier.
Astrocytes
are specialized macrophages of the CNS responsible in
removing damage neurons and infections.
Microglia
CNS cells that line the brain ventricles and
spinal cord central canal, and also help in forming choroid
plexuses that secrete cerebrospinal fluid (CSF).
Ependymal cells
peripheral nervous system (PNS) cells that
surround neuron cell bodies in ganglia (singular: ganglion; clusters
of neural bodies outside the CNS), and provide support and
nutrients.
Satellite cells
are cells of the PNS that are
wrap around portion of one axon to form myelin sheath.
Schwann cells or neurolemmocytes
- composed of the brain
and spinal cord - controls most of the functions of the body and mind
central nervous system (CNS)
composed of sensory neurons and motor
neurons, which are further divided based on their physiologic functions
peripheral nervous system (PNS)