Such Great Potential
Charge inside nerve is -70mV; higher concentration of potassium inside the cell and a higher concentration of sodium ions outside the cell; the movement of K+ is mainly responsible for creating the electrical potential
Resting Potential
Neurons either fire maximally or not at all
All or None Response
Space which divides at least 2 neurons
Synapse
Excitatory or inhibitory; released as rewarding of a behaviour; pleasure
Dopamine
Associated with decreased levels of seretonin
Depression
K+ gates close slowly, so more K+ ions move out than normal; more negative charge inside neuron than normal
Hyperpolaztion
Improves the ability of electrical charge to flow far enough down the axon to reach the next node of Ranvier
Myelin Sheath
DAILY DOUBLE
1 answer
Carry impulses away from synapse
1 answer
Carry impulses to the synapse
Postsynaptic Neuron; Presynaptic Neuron
Generally inhibitory; impacts mood; happiness
Seretonin
Excess dopamine
Schizophrenia
Nerve becomes more permeable to highly concentrated Na+ than K+; rapid influx of Na+ causes -70mV to jump to 40mV
Depolarization
Different for each neuron; a potential stimulus must be above this critical value in order to produce a response
Threshold Level
Enzyme which follows acetylcholine and destroys it; sodium channels are closed, and neuron begins recovery phase
Cholinesterase
Can act as an excitatory transmitter chemical on many postsynaptic neurons by opening Na+ channels, causing depolarization; may also act an an inhibitory transmitter chemical on a different postsynaptic membrane by opening more K gates, K+ on inside of neuron follow concentration gradient and diffuse out of neuron
Acetylcholine
Deterioration of memory and mental capacity; related to decreased production of acetylcholine
Alzheimer's Disease
DAILY DOUBLE (2 answers)
Time required before a neuron can return to resting potential; this time is required to produce another action potential
Refractory Period; Recovery Time
When action potentials jump from node to node without depolarizing the region under the myelin sheath
Saltatory Conduction
Daily Double
1 answer
Triggers potassium channels to open; hyperpolarization; increased threshold level1 answer
Triggers receptor proteins in post synaptic cleft to allow positive ions (eg. sodium) in; depolarization; lowered threshold level
Inhibitory Neurotransmitters; Excitatory Neurotransmitters
Found in CNS and PNS; is excitatory in PNS; excitatory or inhibitory in CNS
Norepinephrine (noradrenaline)
Involuntary muscle contractions and tremors; inadequate production of dopamine
Parkinson's Disease
Na+ channels close, K+ gates open, and K+ diffuses out of cell restoring original polarization
Repolarization
Organisms which don't have myelinated neurons, so they have an increased axon diameter to speed up conduction; the larger the cross-sectional area of a neutron, the further it can conduct electrical charge along the axon
Invertebrates
Chemicals which brave the gap; released by the end plate of presynaptic neuron; move by diffusion
Neurotransmitters
DAILY DOUBLE
1 answer
Inhibitory; reduces pain perception
1 answer
Excitatory; memory
1 answer
Inhibitory; calms the body
Endorphins; Glutamic Acid; GABA
DAILY DOUBLE (1 answer) Theme: Threshold Levels
Theory which dictates that the message (stimulus) priority is determined by the frequency of impulses; some neurons have higher threshold levels, and are only set off with an increased stimulus
Spinal Gate Theory