Chapter 3 Flashcards
Neuron
Specialized cells that make up the nervous system into neural networks
Cell body (soma)
Main part of Neuron, Structures that keep cell alive (Nucleus)
Dendrites
Main part of Neuron, Branches from cell body, receives signals
Axon
Main part of Neuron, Conducts electrical impulses away from the soma
2 Basic functions of Neurons
- Generate electricity to create nerve impluses
- Release chemicals to communicated with other cells
Neural Impulses 1st Step “Resting Potential”
The cell is at rest with electrical resting potential (-70mV)
Neural Impulses 2nd step “Action Potential”
Cell is stimulated and electrical charges (ions) flow across cell membrane (depolarization)
Neural Impulses 3rd step “Restore Resting Potential”
Restore distribution of ions, cell at rest again, Potassium channels now open
The All-or-None law
Action potentials occur at a uniform and maximal intensity or, they do not occur at all.
Note: Stronger signals do not cause stronger action potentials, instead they create more
Myelin sheath
A fatty insulation layer derived from glial cells, insulates neurons
Nodes of Ranvier
places where myelin is either thin or absent, allows conduction to skip ahead
Glial Cells
Holds in place
Make + move more nutrients
Form the Meylin Sheath
Remove toxins (blood-brain barrier)
Synapses
functional connections between neurons and their target
Neurotransmitters basic functions
- Generate electricity to create nerve impulses
- Release Chemicals to communicate with other cells.
Neurotransmitters
Chemical substances that carry messages across the synapse to either excite other neurons or inhibit their firing
5 Stages of Chemical Communication
Synthesis - Make them in the neuron
Storage - held in synaptic vesicles
Release - into synaptic space
Binding - attach to receptor sites
Deactivation - stop the neurotransmitter signals
Excitatory transmitter
Decrease resting potential of post-synaptic neuron, may even fire; depolarization
Inhibitory transmitter
Increase resting potential of post synaptic neuron; hyperpolarization
Glutamate
Excitatory, Expressed in whole brain, Controls behaviors (learning + memory)
GABA
inhibitory, expressed in the whole brain, controls behaviours (anxiety + motor control)
Norepinephrine
Excitatory + Inhibitory, involved in learning, memory, wakefulness, eating, depression, panic disorders
Serotonin
Inhibitory, Functions at various sites, controls mood, eating, sleep, arousal, depression
Dopeamine
Excitatory and inhibitory, functions at various sites, controls voluntary movement, learning, motivation, pleasure, depression, Parkinsons disease, schizophrenia
Forebrain
Highly developed, numerous functions
