Psy 201 Ch 3 Set A: The Neuron

biological - Behavioral Neuroscience; mind and body connection; nervous and endocrine systems; Area of specialization: behavioral neuroscience and physiological/biological perspective

receptor cells (neural receptors); neurons; effector cells; glial cells

located in the sense organs; receive stimulation

transport or transmit messages; located between receptor and effector cells

located near the muscles and glands; tell muscles to contract and glands to secrete

do not send or receive nerve impulses; hold neurons in place; absorb toxins and waste materials that would damage or kill neurons; outnumber neurons about 10 to 1

basic building block of the nervous system; main role is transmit/transport messages; single nerve cell; 100 billion nerve cells; brain and spinal cord; various shapes and sizes; must use microscope; bundle of neurons - nerve; supported by glial (glue) cells

sensory (afferent); interneurons; motor (efferent)

transmit messages from receptor cells in sense organs to CNS

also called association neurons; connect one neuron to another; most located in CNS

transmit messages from the CNS to effector cells near the muscles and glands; muscles contract, glands secrete

the brain and spinal cord

all neurons have three main parts: dendrites, soma (cell body), and axon; other parts: myelin sheath, nodes, axonal terminals, terminal buttons, synaptic vesicles, and synaptic cleft

short fibers; collect messages from neighboring neurons

carry out the basic functions of cell; nucleus is located here

long fiber; message leaves neuron by way of axon; additional structures of neurons

fatty, white substance; surrounds axon; helps message travel down axon; speeds up the impulse

breaks in the myelin sheath; impulse jumps from node to node

end of axon; axon splits into many parts; terminals connect to other neurons

knobs at the end of terminal; house synaptic vesicles

tiny oval sacs; holds the neurotransmitters

gap; space between two neurons

communication between neurons; message is being conducted; neurons do not touch physically; communication is electrochemical in nature; is like a tiny battery

electrically charged particles/atoms (positive or negative)

two states: resting state/potential and acting state/potential; distinction: stimulation/impulse, membrane, ions

no stimulation (not receiving any messages); no impuse; membrane is semi-permeable; cell is more negatively charged inside than outside; condition of cell is polarized

allows some ions to come in while holding others outside

cell is stimulated; neuron has "fired" impulse or message; membrane is permeable; channels open up, more ions flow in; changes condition of cell: depolarized

after firing, cell must rest/recover; two refractory periods: absolute and relative

immediately following action potential; membrane is not excitable; cannot discharge another impuse

immediately following the absolute refractory period; membrane is excitable; impulse must be stronger than the initial impulse (stimulation)

action potentials occur either at a uniform and maximum intensity or they do not occur at all

Two types of chemical reactions can occur (neurotransmitters released): excitatory or inhibitory

causes the action potential; neuron fires

prevents the neuron from firing; each neurotransmitter fits like a lock and key; deactivation must occur, two ways: enzymes and reputake

neurotransmitters can be broken down by other chemicals

transmitter molecules are taken back into the presynaptic axon terminals