Revision - 2 Flashcards
What is not part of the neuron’s function?
The production of myelin
The sodium/potassium pump …
Continuously exchanges three intracellular Na+ for two K+
During an action potential …
The voltage of the cell membrane goes to about +30mV and then drops to -80mV before returning to -70mV
Nerve “impulse” describes …
The movement of an action potential along the axon
Dendrites can receive …
Both excitatory AND inhibitory input
Stimulation producing two ESPs in quick succession illustrates …
Temporal summation
Which of the following are characteristic of the postsynaptic membrane?
Thickened appearance and receptor proteins
A key event in the release of neurotransmitter molecules into the synaptic cleft is the …
Influx of Ca++ ions i n response to the arrival of an action potential at the button (bouton)
Neurotransmitters are produced in the …
Soma and synaptic terminals
What element is not part of the amine subtype of small-molecule neurotransmitters?
Glycine
The correct chronological order of presynaptic events:
1) Action potential reaches axon terminal
2) Calcium ion channel opens
3) Exocytosis
4) Diffusion of neurotransmitter
Acetylcholine is the classical neurotransmitter for …
All skeletal motor synapses
Sympathetic neurons are ___ while parasympathetic neurons are ___
Cholingeric AND adrenergic, ONLY cholinergic
Gamma Amino Butyric Acid (GABA) …
Decreses the firing of cells
A second messanger is …
A chemical in the postsynaptic cell that is activated by a G protein (after receptor stimulation)
Neurotransmitter molecules are secreted from ___ in response to the arrival of an action potential
The axon terminal
The ___ cells support myelination of axons in the peripheral nervous system
Golgi
The ___ is defined as the difference in electrical charge between the inside and the outside of the axon membrane
Membrane potential
The process by which similarly charged particles repel each other and are thus distributed throughout a medium, is termed:
Electrostatic pressure
What event restores the membrane potential from the peak of the action potential back to the resting level?
Potassium ions move out of the cell
The “all-or-none law” refers to the observation that an action potential …
is produced whenever the membrane potential reaches threshold
What is suggested as an advantage associated with myelination?
Myelin prevents cross-talk between adjacent neurons
What is true of receptors?
Neurotransmitters bind to and activate receptors to exert their effects
An electrical charge applied to an axon that moves the membrane potential from -70mV to -45mV will result in an …
Action potential
Movement of the axon membrane potential from -70mV to -65mV would be termed:
Depolarisation
