Neurons and nervous systems

Neuron

a nerve cell; the basic building block of the nervous system

Neuron types

sensory, motor, interneurons

Cell body - neuron

Life center, contains nucleus and organelles

Dendrites- neuron

receives messages from other cells

Axon- neuron

Sends messages away from cell body to neurons, muscle, etc

Neural impulse - neuron

electrical signal traveling down the axon

Terminal branches of axon - neuron

forms junctions with other cells

Myelin sheath - neuron

covers the axon of some neurons and helps speed neural impulses

Synapse- neuron

area where a neuron communicates with another cell

Synapse gap - neuron

The space between a neuron. They never touch.

Communication of neuron

Synapse, synapse gap, neurotransmitter

Neurotransmitter

chemical messengers that cross the synaptic gaps between neurons

Reuptake

process by which neurotransmitters are taken back into the synaptic vesicles

Refractory period

a period of inactivity after a neuron has fired

Excitatory

Causes next cell to fire

Inhibitory

Keeps next cell from firing

Threshold

Level of stimulation needed to trigger a neural impulse

Depolarize

in the nervous system, to lose the charge that normally exists across the neuronal membrane

Acetylcholine

enables muscle action, learning, and memory

Dopamine

influences movement, learning, attention, and emotion

Serotonin

Affects mood, hunger, sleep, and arousal

Norepinephrine

helps control alertness and arousal

GABA

a major inhibitory neurotransmitter

Glutamine

A major excitatory neurotransmitter; involved in memory

Agonist neuron

a drug that mimics the effect of a neurotransmitter

Antagonist neuron

drug/ chemical that blocks action of neurotransmitters

Nervous system

the network of nerve cells and fibers that transmits nerve impulses between parts of the body.

peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body

central nervous system

brain and spinal cord

Autonomic

controls self-regulated action of internal organs and glands

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations. Ex- heartbeat faster

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy EX- slow heartbeat

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.

adrenal glands

epinephrine and norepinephrine.

Adrenaline and noradrenaline.

Fight and flight.

Dituitary Gland

In endocrine system