nervous system subdivisions and tissue

central nervous system (structure)

brain and spinal cord

central nervous system (function)

integrative and control centers

peripheral nervous system (structure)

cranial nerves and spinal nerves

peripheral nervous system (function)

communication lines between the CNS and the rest of the body

sensory/afferent division (structure)

somatic and visceral sensory nerve fibers

sensory/afferent division (function)

conducts impulses from receptors to the CNS

motor/efferent division (structure)

motor nerve fibers

motor/efferent division (function)

conducts impulses from the CNS to effectors (muscles and glands)

somatic nervous system (structure)

somatic (voluntary) motor nerve fibers

somatic nervous system (function)

Conducts impulses from CNS to skeletal muscles

autonomic nervous system (structure)

visceral (involuntary) motor nerve fibers

autonomic nervous system (function)

conducts impulses from the CNS to cardiac muscles, smooth muscles, and glands

sympathetic division (function)

mobilizes body systems during activity (fight or flight)

parasympathetic division (function)

conserves energy, promotes housekeeping functions during rest (rest and digest)

dendrite

receives information from other neurons

cell body (soma)

organizes and keeps cell functional

axon hillock

generates impulse in a neuron; determine propagation of action potential

axon

transfers signals to other cells and organs

schwann cells

produces myelin sheath

myelin sheath

increases speed of signal

nodes of ranvier

allows diffusion of ions

axon terminals

form junctions with other cells

grey matter consists of

cell bodies, dendrites, unmyelinated axons, 40%

grey matter

processes information in brain to spinal cord

white matter consists of

myelinated axons, 60%

white matter

transmits signals between different parts of nervous system

dura matter

outermost, thick, protective

meninges

protective membranes surrounding brain and spinal cord

arachnoid matter

middle layer, contains cerebrospinal fluid, cushions brain and spinal cord

pia matter

innermost, delicate and adheres to surface of brain and spinal cord, contains blood vessels

dorsal root

carries sensory information from the body to spinal cord

dorsal root ganglion

receives sensory input; relays points, signals from peripheral receptors passes to spinal cord

ventral root

carry motor information from spinal cord to muscles

dorsal ramus

carries sensory and motor fibers, supplies muscles and skin to posterior trunk

ventral ramus

carries sensory and motor fibers, supplies anterior and lateral trunk (cervical, lumbar, brachial, sacral plexus)