Neurons Flashcards
Signaling
Coordinates body functions
Difference between endocrine system and nervous system?
Endocrine system: has hormones as signalers, is slow-acting, prolonged effects
Nervous system: neurotransmitters as signalers, fast-acting, ephemeral effects (stimulus -> action -> over)
Neurons
Highly specialized for information processing; has dendrites, cell body w/nucleus, axon hillock, axons covered w/ myelin sheath, nodes of Ranvier, axon terminals, and synapses
Dendrites
Top of the neuron that receives signals
Cell body
Also called soma contains nucleus
Axon hillock
Determines whether or not to fire the signal through the neuron
Axon
Includes myelin sheath and nodes of Ranvier where the signal travels through
Myelin sheath
Covers the axon and acts as a fatty insulator; makes the signal travel faster)
Nodes of Ranvier
Gaps between myelin sheath that the signal lands on after jumping over myelin sheath
Axon terminals
End of an axon and has synapses
Synapses
Connect w/ another neuron and transfers signal
How many neurons typically make up a circuit?
2-3
How many sodium ions are pumped for how many potassium ions?
3 sodiums for 2 potassiums
What does it mean when there is more Na+ ions outside and K+ ions inside?
More positive outside and more negative inside
Hyperpolarization
Removing positive charges and resting potential becomes more negative; cell does not fire