Chapter 2 Flashcards
(50 cards)
Neural Communication
The body’s information system is built from billions of interconnected cells (neurons)
Soma
Cell body
Life support center of the neuron, has a nucleus
Dendrites
Fiber extensions off the cell body that receives messages from other neurons
Axon
Long single extension of neuron (varies in length) that passes messages to other neurons, glands, and neurons
Myelin Sheath
A layered, white-ish fatty substance that covers the axon
It insulates and speeds up messages through neurons
Terminal Branches
Endings of an axon
Bulb
Top of the branches, filled with neurotransmitters
Neurotransmitter
Sends messages to other neurons
Nodes of Ranvier
Spaces between the myelin sheath sections
Hillack
Point at which the soma meets axon
Synapse
Space between neurons; neurotransmitters and following dendrites
Resting Potential
Normal resting stage where positive ions are outside of axon while negative ions are inside
Depolarization
Axon is fired, thus allowing positively charged ions to enter
Threshold
Minimum amount of intensity one may take before axon fires
Action Potential
Exceeds minimum intensity when neuron fires strong throughout axon or not at all
Direction of Impulse
Cell body —–> Bulbs Terminal
All or None Principle
Go hard or go home!
Will fire at full force or doesn’t at all
Refractory Period
Axon rests and tells positive ions to go back outside where it belongs
Back to normal stage
Excitatory
Inhibitory
Accelerator
Brake
Re-uptake
Applies the brakes on neurotransmitter action
Lock and Key Mechanism
Neurotransmitters bind to the receptors of the receiving neuron
Glial Cells
Housekeeper of the nervous system
Keeping extracellular environment clean of debris
Acetylcholine (AcH)
Memory process, muscle action, learning
Too little: alzheimer’s
Norepinephrine
Stimulate heart beat, arousal, alertness
Too little: depressed moods
