Lecture 1
Chapter 3.5 - Biology and behavior
Gene expression: Whether a particular gene is turned on or off.
Chromosomes: Structures within the cell body that are made up of DNA, segments of which
comprise individual genes.
Genes: The units of heredity that help determine the characteristics of an organism.
Dominant gene: A gene that is expressed in the offspring whenever it is present.
Recessive gene: A gene that is expressed only when it is matched with a similar gene from
the other parent.
Genotype: The genetic constitution of an organism, determined at the moment of
conception.
Phenotype: Observable physical characteristics, which result from both genetic and
environmental influences.
Monozygotic twins: Also called identical twins; twin siblings that result from one zygote
splitting in two and therefore share the same genes.
Dizygotic twins: Also called fraternal twins; twin siblings that result from two separately
fertilized eggs and therefore are no more similar genetically than non twin siblings.
Heritability: A statistical estimate of the extent to which variation in a trait within a
population is due to genetics.
Natural selection: In evolutionary theory, the idea that those who inherit characteristics that
help them adapt to their particular environments have a selective advantage over those who
do not.
Lecture 2
Chapter 3.1,3.2,3.3,3.4 - Biology and behavior
Neurons: The basic units of the nervous system; cells that receive, integrate, and transmit
information in the nervous system. They operate through electrical impulses, communicate
with other neurons through chemical signals, and form neural networks.
Central nervous system (CNS): The brain and the spinal cord.
Peripheral nervous system (PNS): All nerve cells in the body that are not
,part of the central nervous system. The peripheral nervous system includes the somatic and
autonomic nervous systems.
Sensory neurons: One of the three types of neurons; these neurons detect information
from the physical world and pass that information to the brain.
Motor neurons: One of the three types of neurons; these neurons direct muscles to contract
or relax, thereby producing movement.
Interneurons: One of the three types of neurons; these neurons communicate within local
or short-distance circuits.
Dendrites: Branch like extensions of the neuron that detect information from other neurons.
Cell body: The site in the neuron where information from thousands of other neurons is
collected and integrated.
Axon: A long narrow outgrowth of a neuron by which information is transmitted to other
neurons.
Terminal buttons: At the ends of axons, small nodules that release chemical signals from
the neuron into the synapse.
Synapse: The gap between the axon of a “sending” neuron and the dendrites of a
“receiving” neuron; the site at which chemical communication occurs between neurons.
Resting membrane potential: The electrical charge of a neuron when it is not active.
Action potential: The electrical signal that passes along the axon and subsequently causes
the release of chemicals from the terminal
buttons.
,Myelin sheath: A fatty material, made up of glial cells, that insulates some axons to allow for
faster movement of electrical impulses
along the axon.
Nodes of Ranvier: Small gaps of exposed axon, between the segments of myelin sheath,
where action potentials take place.
All-or-none principle: The principle that when a neuron fires, it fires with the same potency
each time; a neuron either fires or not—it cannot partially fire, although the frequency of
firing can vary.
Neurotransmitters: Chemical substances that transmit signals from one neuron to another.
Receptors: In neurons, specialized protein molecules on the postsynaptic
, membrane; neurotransmitters bind to these molecules after passing across
the synapse.
Reuptake: The process whereby a neurotransmitter is taken back into
the presynaptic terminal buttons, thereby stopping its activity.
Acetylcholine (ACh): The neurotransmitter responsible for motor control at the junction
between nerves and muscles; it is also involved in mental processes such as learning,
memory, sleeping, and dreaming.
Epinephrine: A monoamine neurotransmitter responsible for bursts of energy after an event
that is exciting or threatening.
Norepinephrine: A monoamine neurotransmitter involved in states of arousal and attention.
Serotonin: A monoamine neurotransmitter important for a wide range of
psychological activity, including emotional states, impulse control, and dreaming.
Dopamine: A monoamine neurotransmitter involved in motivation, reward,
and motor control over voluntary movement.
GABA: Gamma-aminobutyric acid; the primary inhibitory transmitter in the
nervous system.
Glutamate: The primary excitatory transmitter in the nervous system.
Endorphins: Neurotransmitters involved in natural pain reduction and reward.
