The Nervous System Flashcards
2 types of neural cells
Neurons and Glia
The CNS consists of:
The brain and the spinal cord
What does the CNS do?
it receives, processes, stores and transfers information
The two subdivisions of the PNS
the sensory division and the motor division
the input neuron is called
the sensory neuron
the communication neuron is called
the interneuron
the output neuron is called
the motor neuron
what do glial cells provide?
support/glue
Neurons are cells specialized for…
communication
type of neuron specialized to respond to a certain type of stimulus such as pressure or light
sensory neuron
type of neuron that transmits impulses away from the CNs
motor neuron
how many neurons are in the human nervous system?
85 billion
All neurons consist of what parts
a cell body, one or more dendrites and an axon
the main body of a neuron
the cell body
where is the nucleus located in neurons?
the cell body
slender extensions of the cell body that receive information from other neurons
dendrites
the long, slender tube of cell membrane containing a small amount of cytoplasm, a part of a neuron:
the axon
axons of sensory neurons originate from a …
dendrite
axons from an interneuron and motor neuron originate from
the point of union with the cell body called the axon hillock
at the other end of axons, axon branches into slender extensions called
axon terminals
axon terminals end in small rounded tips called
axon bulbs
types of cells that provide physical support and protection to neurons and help maintain healthy concentrations of important chemicals in the fluid surrounding them
glial cells
what do neuroglial cells not generate?
impulses
type of cell in brain and spinal cord that act as the first and main form of active immune defense in the CNS
Microglia
the garbage collecting glial cell is called
macrophage
the generic term for cells in the CNS which are neither neurons, nor microglia
macroglia
the most abundant type of macroglia
astrocytes
the name astrocyte is because of
the shape of a star
two major functions of astrocytes
neuron support and component of blood brain barrier
3 types of macroglia
atrocytes, oligodendrocytes and schwann cells
where are oligodendrocytes ?
wrapped around axons in the CNS