3A.1.1, 3A.1.2, 3A.1.3 Flashcards
Sensory neuron
Neurons that carry incoming information from the sensory receptors to the brain and spinal cord
Motor neutron
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Interneurons
Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor inputs
Dendrite
The bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body
Axon
The extension of a neuron, ending in branching terminal fibers, through which messages pass to ther neurons it to muscles or glands
Axons ____ dendrites _____
Speak, listen
Myelin sheath
A layer of fatty tissue segment ally encasing the fibers of many neurons; enables vastly greater transmission speed of neutral impulses as the impulse hops from one node to the next
A neutral impulse travels at….
speeds ranging from 2 mph to 200 mph
Your brain is more complex that a computer….
But slower at executing simple responses
Action potential
A neural impulse; a brief electrical charge that travels down an axon
Neurons generate electricity from…
Chemical events
Chemistry to electricity process…
Involves the exchange of ions
Inside of an axon is _____, the membrane is ____
Negatively charged, positively charged
Selectively permeable
Selective about what it lets in
Each neuron is like a….
Mini-decision making device
Excitatory:_____ inhibitory:________
Accelerator; brake
Threshold
The level of stimulation required to trigger a neural impulse
If excitatory exceeds inhibitory….
It triggers an action potential
Synapse
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic deft
Dendrites and axons….
Don’t touch
Neurotransmitters
Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the recovering neuron, thereby influencing whether that neuron will generate a neural impulse
Reuptake
A neurotransmitter’s reabsorption by the sending neuron
Acetylcholine
The messenger at every junction between a motor neuron and skeletal muscle
Endorphins
“Morphine within”; natural opiatelike neurotransmitters linked to pain control and to pleasure