Nervous System BIOL 102

central nervous system

encompases the brain and spinal chord, lies in midline of body

peripheral nervous system

contains cranial nerves and spinal nerves, gathers info from sensors and effectors

dentrides

receive signals from sensory receptors

axon

conducts nerve impuse, covered in myelin sheath

nerve fiber

name of long axon

cell body

this part of a neuron contains the nucleus

sensory neurons

accept impulses from sensory receptors b4 transmitting them to CNS

motor neurons

accept nerve impuls from CNS, go to muscles or glands

interneurons (relay)

convey nerve impulses between various parts of CNS

resting membrane potential

created and maintained by increasing the concentration of cations outside the cell relative to inside the cell

membrane potential

difference in electrical charge (voltage) across a cell membrane due to the differential distribution of ions

voltage-gated ion channels

regulated the relative concentrations of different ions inside and outside of the cell - Na+ channels and K+ channels

nodes of ranvier

gaps in myelin coverage along axons - action potentials travel down axon by jumping from one node to another

meninges

covering for spinal cord and brain, has to be peeled to get to brain

cerebrospinal fluid

fluid spaces between meninges

matter

spinal chord appears differnt because it is made of up different types of

somatic nervous system

tansmits sensory and motor singals to and from the central nervous system

autonomic nervous system

controls smooth muscles, cardiac muscle, organs, and glands, unaware of action

sympathetic

part of autonomic nervous system, fight or flight

parasympathetic

normal conditions, autonomic nervous system