Chapter 3-Biology and Behavior Flashcards
(41 cards)
neurons
are the basic units of the nervous system since they receive(take in), integrate(asses incoming signals) and transmit(pass own signals to others) information in the system. They communicate through neutral networks among neurons.
central nervous system
includes the brain and spinal cord nerve cells
peripheral nervous system
includes all other nervous cells except those in the CNS
sensory neurons
also called afferent neurons since they detect external info and transmit it to the brain..example….touching a hot object and instantly removing hand(somatosensory)
motor neurons
efferent neurons that direct muscles to contract or relax by transmitting signals from the brain to the rest of the body
inter neurons
communicate within local neurons only
neuron structure=dendrites, cell body, axon, terminal butto
the dendrites are the branches at the end of the neuron that receives signals from other neuron’s terminal buttons. The center within the branches is the cell body aka soma where signals are processed and transmitted along the axon with nodes between the segments of the axon.From here the signal is sent from the terminal buttons in the synapse
dendrites
branching extensions that detect information from neighboring neurons
soma(cell body)
collects and assesses info from other neurons
Axon
chain that transmits the signals onto the terminal buttons
synapse
space where neurons communicate it contains the synaptic cleft which is the gap between the two neurons
Action potential(neural firing)
the neural impulse that are passed down the axon, this occurs in a 3 step process within each node. First its at a resting period and then the action potential which is when potassium and sodium channels open and when they eventually close the potential returns to resting state.
ALL or NONE:action potential
the actions potential within each node of the axon either happens or it doesn’t since there is no partial firing off the signals. The strength of the firing is constant and doesn’t go weaker or stronger with a particular stimuli…example…paying a video game and shooting a missile by pressing a button..the missile will be shot at the same strength regardless of how hard you push the button.
refractory period
period in which the neuron cannot fire since sodium ions are no longer rushing into the sodium channels nor is potassium rushing out. the resting period is when there is a slightly negative charge within(creating polarization-so its at rest), because the the positive ion channels close
excitatory signal
the signal for postsynaptic neurons that encourages the neuron to fire.
inhibitory signal
discourages the neuron from firing
5 steps of neutrotransmitter release
1) nuerotransmitter made in the axon,2)it is then stored in vesicles, 3)vesicles attach to presynaptic membrane, the membrane opens and releases the stored nuerotrasmitter to the synaptic cleft, as a result of action potential 4) these then bind to receptors on the postsynaptic of another neurons dendrite 5)if the released neurotransmitter is unbound then it is terminated by reuptake, deactivation, and autoreception
reuptake
if the neurotransmitter does not bind to the postsynaptic membrane on the dendrite than it is taken in by the presynaptic membrane again
deactivation
this is another termination process for the neurotransmittter that does not bind to the postsynaptic membrane….if deactivation occurs than it is terminated by being broken down by enzymes in the synapse.
autoreception
the released neurotransmitter may bind to the presynaptic neurons
examples of neurotransmitters
Acetylcholine-Ach, motor control of muscles, learning, memry………..Dopamine(DA)-voluntary movement, reward, motivation,,,,Seratonin(5)HT)-mood, hunger, sleep, attentiveness…..Norepinephrine(NE)-alertness and vigilance……Gamma(GABA)-primary inhibitor neurotrans..ar..if not present seizures and tremors…Glutamate(Glu)-primary exitatory neurotrans learning & memory
brain stem-(central nervous system-part)
this part of the brain includes the midbrain, pons, and medulla oblongata…the brain stem is vital for surivival since it regulates heart rate, respiration, vomiting.
cerebellum
coordinates movement and balance. So every lobe controls diff functions related to motor behavior
Hypothalamus
regulated body functions such as thirst hunger aggression and sexual behavior, also controls the endocrine system(communication network influencing thought, behavior, actions)
