Chapter 3-Biology and Behavior Flashcards
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)
Thalamus
center for all sensory info except smell which in contrast goes directly to the cerebral cortex
hippocampus
memory formation, May be subject to plasticity(change of the brain as a result to experience, drug, or injury..london cab drivers have bigger hippocampus(more memorization)
amygdala
emotional association(+ or -)…associating expereince with emotions…ex eating an unpleasant food with disgust.The amygdala plays imp. role in responding to fear stimuli
basal ganglia
crucial for planning and producing movement, they receive info from the entire cerebral cortex.any damage can lead to uncontrolled jerk movements.It contains the nucleus ganglia which is important for reward and motivation(from pleasurable experience)
cerebral cortex
it is the uttermost layer of the brain and it is responsible for sensory integration(assessment), thought production, and complex behavior.t contains 4 lobes–occipital(vision, parietal(touch, spatial relations), temporal(auditory and memory), and frontal(thought, planning, movement..),
occipital lobe
located at back part of the brain and are almost exclusively for vision , Vision is projected from the eye to the cerebral cortex
homunculuc
shows a representation of the whole body indicating how much of the brain is in charge of each body part and function.
autonomic
involuntary muscle movement,
somatic
voluntary muscle movement
contra lateral organization
right part of brain control the left part of body and left part of the brain controls the right part of body.
differences btw endocrine and nervous system
nervous system has neurotransmitter that are released from terminal buttons, they travel short distances, and are fast-acting…….endocrine system has hormones released from endocrine glands and travel throughout the body but are slow
pituary gland
the gland releasomg hormones from the cns to the periphery
oxytocin
uterine contraction, lactation, romantic relationships
vasopressin
social bonds, water balance, chronic stress regulation
monozygotic twins(identical)
occurs when one zygote splits into 2,with same genetic info,and same prenatal enviroment
dizygotic (frtaternal)
two zygotes develop at same time. differemt genes same prenatal environment/
apoptis
intentional cell death
