nervous system Flashcards
(21 cards)
ion
An atom or group of atoms that has gained or lost electrons, resulting in it having an electrical charge; both chemical and electrical charge
homeostasis
the body’s desire for and ability to maintain a stable internal environment
neuron
a nerve cell
synapse
A specialized connective tissue found between neurons;the connection between the axon terminal of one neuron and the dendrite of another neuron; formed by learning (integration of stimulus)
axon
A long “cable” that extends from a neuron, carrying electrical impulses that are traveling away from the cell in order to communicate with other neurons.
schwann cell
Specialize cells that “insulate” the axon fibers, using a material called the myelin sheath; this myelin sheath insulation helps the neuron communicate more quickly
nodes of ranvier
Small sections of exposed axon fibers that are not insulated by Schwann cells.
action potential
The trading of ions (because of unbalanced chemical/electrical concentration) that creates the transmission of a nerve impulse.
resting potential
The difference in chemical and electrical concentrations in a neuron, creating the potential/pressure to move a signal.
refractory period
The time it takes for a neuron to readjust the Na and K levels through a pump, during which time no new impulse can be transmitted.
synaptic plasticity
The strength or weakness of synaptic connections based on the level of usage; allows for adaptations to neural circuits
charge in neuron
electrical
charge in synaptic cleft
chemical
what do neurons need
sodium, potassium, calcium
central nervous system
Receives, processes, responds to, and regulates signals from; control center. (brain and spinal cord)
peripheral nervous system
carries information to and from the brain/body.
somatic nervous system
Voluntary system responsible for sensory and motor functions.
automatic nervous system
Involuntary system that manages a stable internal environment through heart rate, breathing, digestion, blood pressure, and arousal.
sympathetic nervous system
Prepares the body for immediate responses to stress and danger, initiating the (fight or flight) response.
parasympathetic nervous system
Calms the body down after a sympathetic response and maintains homeostasis/relaxation.
vagus nerve
Major nerve in the parasympathetic nervous system, which connects the brain to the gut, influencing mood, stress regulation and cognitive function
