structure and parts of a neuron

neuron

basic units of the brain that send electrical signals to different parts of the body

phospholipids

these form a bilayer to make up a neuron’s cell membrane, and consist of two hydrophobic tails and a hydrophilic end

86 billion

the number of neurons we have in our brain

electroactive

neurons are charged cells that can change their charge

neurogenesis

the creation of new neurons

olfactory system and the hippocampus

two areas of the brain that display neurogenesis

neuroplasticity

neurons’ ability to heal and change their functions

dendrites

the main target for incoming signals sent from other cells

spines

these increase the dendrite’s surface area and are the sites for some synaptic contacts

dendritic plasticity

submicroscopic changes to the morphology of dendritic spines

cell body/soma

process signals from dendrites, decides whether to send signal to next neuron

cell membrane

responsible for weighing all incoming signals

axon

main output extension of the neuron

axon hillock

where the cell body transitions into the axon

nerves

several axons bundled that travel together

sciatic nerve

the longest axon in the human body

action potential

electrical signal will result in a release of chemical neurotransmitters to communicate with the next cell

myelin sheath

a fatty substance that wraps around portions of the axon and increases action potential speed

nodes of ranvier

breaks between the myelin segments, regenerates the action potential as it propagates down the axon in a process called saltatory conduction

length of an axon is variable depending on…

location and function

axon diameter affects…

action potential speed, myelin thickness

axoplasmic transport

the movement of materials (vesicles, organelles, proteins) within an axon

anterograde transport

cell body to terminal

retrograde transport

terminal to cell body

kinesin

protein used in anterograde transport

dynein

protein used in retrograde transport

synapse

the physical distance that separates two neurons

unipolar neurons

have only one branch from the cell body, and the dendrites and axon terminals project from it

bipolar neurons

have one axonal branch and one dendritic branch

multipolar neurons

have many processes branching from the cell body