Neurons and related cells Flashcards
What are the main components of a typical neuron?
Cell body (soma), axon hillock, axon, terminal branches, dendrites.
What is the function of dendrites?
Dendrites receive signals from other neurons.
What is the role of the axon?
The axon transmits electrical impulses away from the cell body.
What occurs at the axon hillock?
The axon hillock integrates signals and initiates action potentials.
What are terminal branches?
Terminal branches are the endings of the axon that release neurotransmitters.
What is the difference between graded and action potentials?
Graded potentials are variable in amplitude, while action potentials are all-or-nothing events.
What are the four main phases of an action potential?
Resting membrane potential, depolarization, repolarization, hyperpolarization.
What is the refractory period?
The refractory period is the time during which a neuron cannot fire another action potential, ensuring directionality.
What are the three main functional classes of neurons?
Sensory neurons, interneurons, motor neurons.
What occurs at a typical chemical synapse?
Presynaptic neurons release neurotransmitters that activate post-synaptic receptors, leading to changes in membrane potential.
What is the function of SNARE proteins?
SNARE proteins facilitate the fusion of vesicles with the presynaptic membrane to release neurotransmitters.
What is the general role of glial cells?
Glial cells surround and support neurons, provide electrical insulation, supply nutrients, and maintain the chemical environment.
What are common mechanisms of age-related neuronal deterioration?
Neuronal atrophy, loss of myelination, and impaired regeneration.
What are the central mechanisms of nerve aging?
Neuronal atrophy, loss of myelination, noisy processing, and dopamine loss.
What are the peripheral mechanisms of nerve aging?
Declined axonal transport, axonal atrophy, myelin loss, and impaired regeneration.
