writing prompts - exam two

action potential

a rapid change in membrane potential due to the movement of ions across the neuron's membrane.

resting membrane potential

the voltage of a neuron at rest, typically around -70 mV.

threshold

the membrane potential that must be reached for an action potential to occur, typically -55 mV.

depolarization

the process of the membrane potential becoming more positive, often due to Na+ influx.

repolarization

the return of the membrane potential to a negative value after depolarization, often due to K+ efflux.

all-or-None Principle

the principle stating that if a neuron fires an action potential, it does so fully, or not at all.

graded potentials

small changes in membrane potential that can be excitatory or inhibitory and vary in strength.

summation

the process by which multiple graded potentials add together to determine if an action potential starts.

saltatory Conduction

the rapid transmission of action potentials along myelinated axons, jumping between nodes of ranvier.

synaptic transmission

the process of signal transmission at a synapse, involving neurotransmitter release and receptor binding.

ligand-gated receptors

receptors that open ion channels directly upon ligand binding, causing quick cellular responses.

g-protein coupled receptors (GPCRs)

receptors that activate a G-protein, leading to slower, more prolonged cellular responses.

sympathetic nervous system

the part of the autonomic nervous system that increases heart rate during stress or exercise.

endocrine system

the system that releases hormones into the bloodstream, affecting various physiological processes.

photoreceptors

cells in the retina (rods and cones) that detect light and contribute to vision.

hair cells

Sensory cells in the cochlea that transduce sound waves into electrical signals for hearing.